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What is Alloying of High-speed and Tool Steels – Definition

The four major alloying elements in high-speed steels and tool steels are: tungsten, chromium, vanadium and molybdenum. These alloying elements combine with carbon to form very hard and wear-resistant carbide compounds.

Tool Steel

Tool steel
Tool steel refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools.

Tool steel refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools (punches, dies, molds, tools for cutting, blanking, forming, drawing, steering and slitting tools). Their suitability comes from their distinctive hardness, resistance to abrasion and deformation, and their ability to hold a cutting edge at elevated temperatures. With a carbon content between 0.5% and 1.5%, tool steels are manufactured under carefully controlled conditions to produce the required quality. The presence of carbides in their matrix plays the dominant role in the qualities of tool steel.

They are generally grouped into two classes:

  • Plain carbon steels containing a high percentage of carbon, about 0.80-1.50%
  • Alloy tool steels, in which other elements (chromium, molybdenum, vanadium, tungsten and cobalt) are added to provide greater strength, toughness, corrosion and heat resistance of steel.

One of subgroups of tool steels is high-speed steels (HSS), which were named primarily for their ability to machine and cut materials at high speeds (high hot hardness). It is often used in power-saw blades and drill bits. This group of tool steels is described in a separate article.

High-speed Steel

High speed steel
High speed steel (HSS) is a tool steel with high hardness, high wear resistance and high heat resistance. High-speed steel is often used in power-saw blades and drill bits.

High-speed steels, abbreviated as HSS, are a specialized class of tool steels that were named primarily for their ability to machine and cut materials at high speeds (high hot hardness). It is often used in power-saw blades and drill bits. High-speed steel is superior to the older high-carbon steel tools in that it can withstand higher temperatures without losing its temper (hardness). High-speed steels are complex iron-base alloys of carbon, chromium, vanadium, molybdenum, or tungsten, or combinations there of. To achieve good cutting performance from HSS, an appropriate hardening response must be provided in heat treatment.

Central to the performance of high-speed steels is the hardening response achieved during the heat treatment process. Alloying elements are introduced in quantities given by the  intended application and by their function in the heat treatment process, whether to increase the solidus temperature or inhibit the growth of secondary hardening precipitates, enabling higher operating temperature.

M2 high-speed steel

Alloying Agents in High-speed and Tool Steels

High-speed steel - M8
High-speed steel – M8

Pure iron is too soft to be used for the purpose of structure, but the addition of small quantities of other elements (carbon, manganese or silicon for instance) greatly increases its mechanical strength. The synergistic effect of alloying elements and heat treatment produces a tremendous variety of microstructures and properties. The four major alloying elements that form carbides in high-speed steels are: tungsten, chromium, vanadium and molybdenum. These alloying elements combine with carbon to form very hard and wear-resistant carbide compounds. The microstructure of high-speed steels consists of a martensitic matrix with a dispersion of two sets of carbides. These carbides are usually known as primary and secondary carbides. Primary carbides are those carbides formed during solidification of the steel. Secondary carbides are those carbides formed during secondary hardening heat-treatment of the steels.

  • Tungsten. Produces stable carbides and refines grain size so as to increase hardness, particularly at high temperatures. Tungsten is used extensively in high-speed tool steels and has been proposed as a substitute for molybdenum in reduced-activation ferritic steels for nuclear applications. The addition of about 10% of tungsten and molybdenum in total maximises efficiently the hardness and toughness of high speed steels and maintains those properties at the high temperatures generated when cutting metals. Tungsten and molybdenum are  interchangeable at an atomic level and both promote resistance to tempering which gives improved tool cutting performance at higher   temperatures.
  • Chromium. Chromium increases hardness, strength, and corrosion resistance. The strengthening effect of forming stable metal carbides at the grain boundaries and the strong increase in corrosion resistance made chromium an important alloying material for steel. Generally speaking, the concentration specified for most grades is approximately 4%. This level appears to result in the best balance between hardness and toughness. Chromium plays an important role in the hardening mechanism and is considered irreplaceable. At higher temperatures, chromium contributes increased strength. It is ordinarily used for applications of this nature in conjunction with molybdenum.
  • Molybdenum. Molybdenum (about 0.50-8.00%) when added to a tool steel makes it more resistant to high temperature. Molybdenum increases hardenability and strength, particularly at high temperatures due to the high melting point of molybdenum. Molybdenum is unique in the extent to which it increases the high-temperature tensile and creep strengths of steel. It retards the transformation of austenite to pearlite far more than it does the transformation of austenite to bainite; thus, bainite may be produced by continuous cooling of molybdenum-containing steels.
  • Vanadium. Vanadium is generally added to steel to inhibit grain growth during heat treatment. In controlling grain growth, it improves both the strength and toughness of hardened and tempered steels. The size of the grain determines the properties of the metal. For example, smaller grain size increases tensile strength and tends to increase ductility. A larger grain size is preferred for improved high-temperature creep properties. Vanadium is added to promote abrasion resistance and to produce hard and stable carbides which being only partly soluble, release little carbon into the matrix.

 

References:
Materials Science:

U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 2 and 2. January 1993.
William D. Callister, David G. Rethwisch. Materials Science and Engineering: An Introduction 9th Edition, Wiley; 9 edition (December 4, 2013), ISBN-13: 978-1118324578.
Eberhart, Mark (2003). Why Things Break: Understanding the World by the Way It Comes Apart. Harmony. ISBN 978-1-4000-4760-4.
Gaskell, David R. (1995). Introduction to the thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. ISBN 978-1-56032-992-3.
González-Viñas, W. & Mancini, H.L. (2004). An Introduction to Materials Science. Princeton University Press. ISBN 978-0-691-07097-1.
Ashby, Michael; Hugh Shercliff; David Cebon (2007). Materials: engineering, science, processing and design (1st ed.). Butterworth-Heinemann. ISBN 978-0-7506-8391-3.
J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.

See above:
High-speed Steel

We hope, this article, Alloying of High-speed and Tool Steels, helps you. If so, give us a like in the sidebar. Main purpose of this website is to help the public to learn some interesting and important information about materials and their properties.

What is Strength of High-speed Steel – Definition

Ultimate tensile strength of high-speed steel – AISI M2 depends on heat treatment process, but it is about 1200 MPa. Strength of High-speed Steel
High speed steel
High speed steel (HSS) is a tool steel with high hardness, high wear resistance and high heat resistance. High-speed steel is often used in power-saw blades and drill bits.

High-speed steels, abbreviated as HSS, are a specialized class of tool steels that were named primarily for their ability to machine and cut materials at high speeds (high hot hardness). It is often used in power-saw blades and drill bits. High-speed steel is superior to the older high-carbon steel tools in that it can withstand higher temperatures without losing its temper (hardness). High-speed steels are complex iron-base alloys of carbon, chromium, vanadium, molybdenum, or tungsten, or combinations there of. To achieve good cutting performance from HSS, an appropriate hardening response must be provided in heat treatment.

Central to the performance of high-speed steels is the hardening response achieved during the heat treatment process. Alloying elements are introduced in quantities given by the  intended application and by their function in the heat treatment process, whether to increase the solidus temperature or inhibit the growth of secondary hardening precipitates, enabling higher operating temperature.

Strength of High-speed Steel – AISI M2

In mechanics of materials, the strength of a material is its ability to withstand an applied load without failure or plastic deformation. Strength of materials basically considers the relationship between the external loads applied to a material and the resulting deformation or change in material dimensions. Strength of a material is its ability to withstand this applied load without failure or plastic deformation.

Ultimate Tensile Strength

Ultimate tensile strength of high-speed steel – AISI M2 depends on heat treatment process, but it is about 1200 MPa.

Yield Strength - Ultimate Tensile Strength - Table of MaterialsThe ultimate tensile strength is the maximum on the engineering stress-strain curve. This corresponds to the maximum stress that can be sustained by a structure in tension. Ultimate tensile strength is often shortened to “tensile strength” or even to “the ultimate.”  If this stress is applied and maintained, fracture will result. Often, this value is significantly more than the yield stress (as much as 50 to 60 percent more than the yield for some types of metals). When a ductile material reaches its ultimate strength, it experiences necking where the cross-sectional area reduces locally. The stress-strain curve contains no higher stress than the ultimate strength. Even though deformations can continue to increase, the stress usually decreases after the ultimate strength has been achieved. It is an intensive property; therefore its value does not depend on the size of the test specimen. However, it is dependent on other factors, such as the preparation of the specimen, the presence or otherwise of surface defects, and the temperature of the test environment and material. Ultimate tensile strengths vary from 50 MPa for an aluminum to as high as 3000 MPa for very high-strength steels.

Yield Strength

Yield strength of high-speed steel – AISI M2 depends on heat treatment process, but it is about 1000 MPa. Compressive yield strength is about 3250 Mpa.

The yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning plastic behavior. Yield strength or yield stress is the material property defined as the stress at which a material begins to deform plastically whereas yield point is the point where nonlinear (elastic + plastic) deformation begins. Prior to the yield point, the material will deform elastically and will return to its original shape when the applied stress is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible. Some steels and other materials exhibit a behaviour termed a yield point phenomenon. Yield strengths vary from 35 MPa for a low-strength aluminum to greater than 1400 MPa for very high-strength steels.

Young’s Modulus of Elasticity

Young’s modulus of elasticity of high-speed steel – AISI M2 is 200 GPa.

The Young’s modulus of elasticity is the elastic modulus for tensile and compressive stress in the linear elasticity regime of a uniaxial deformation and is usually assessed by tensile tests. Up to a limiting stress, a body will be able to recover its dimensions on removal of the load. The applied stresses cause the atoms in a crystal to move from their equilibrium position. All the atoms are displaced the same amount and still maintain their relative geometry. When the stresses are removed, all the atoms return to their original positions and no permanent deformation occurs. According to the Hooke’s law, the stress is proportional to the strain (in the elastic region), and the slope is Young’s modulus. Young’s modulus is equal to the longitudinal stress divided by the strain.

References:
Materials Science:

U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 2 and 2. January 1993.
William D. Callister, David G. Rethwisch. Materials Science and Engineering: An Introduction 9th Edition, Wiley; 9 edition (December 4, 2013), ISBN-13: 978-1118324578.
Eberhart, Mark (2003). Why Things Break: Understanding the World by the Way It Comes Apart. Harmony. ISBN 978-1-4000-4760-4.
Gaskell, David R. (1995). Introduction to the thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. ISBN 978-1-56032-992-3.
González-Viñas, W. & Mancini, H.L. (2004). An Introduction to Materials Science. Princeton University Press. ISBN 978-0-691-07097-1.
Ashby, Michael; Hugh Shercliff; David Cebon (2007). Materials: engineering, science, processing and design (1st ed.). Butterworth-Heinemann. ISBN 978-0-7506-8391-3.
J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.

See above:
High-speed Steel

We hope, this article, Strength of High-speed Steel, helps you. If so, give us a like in the sidebar. Main purpose of this website is to help the public to learn some interesting and important information about materials and their properties.

What is Hardness of High-speed Steel – Definition

Rockwell hardness of high-speed steel – AISI M2 depends on heat treatment process, but it is approximately 65 HRC. Hardness of High-speed Steel
High speed steel
High speed steel (HSS) is a tool steel with high hardness, high wear resistance and high heat resistance. High-speed steel is often used in power-saw blades and drill bits.

High-speed steels, abbreviated as HSS, are a specialized class of tool steels that were named primarily for their ability to machine and cut materials at high speeds (high hot hardness). It is often used in power-saw blades and drill bits. High-speed steel is superior to the older high-carbon steel tools in that it can withstand higher temperatures without losing its temper (hardness). High-speed steels are complex iron-base alloys of carbon, chromium, vanadium, molybdenum, or tungsten, or combinations there of. To achieve good cutting performance from HSS, an appropriate hardening response must be provided in heat treatment.

Central to the performance of high-speed steels is the hardening response achieved during the heat treatment process. Alloying elements are introduced in quantities given by the  intended application and by their function in the heat treatment process, whether to increase the solidus temperature or inhibit the growth of secondary hardening precipitates, enabling higher operating temperature.

Hardness of High-speed Steel – AISI M2

Rockwell hardness of high-speed steel – AISI M2 depends on heat treatment process, but it is approximately 65 HRC.

Brinell hardness number

Rockwell hardness test is one of the most common indentation hardness tests, that has been developed for hardness testing. In contrast to Brinell test, the Rockwell tester measures the depth of penetration of an indenter under a large load (major load) compared to the penetration made by a preload (minor load). The minor load establishes the zero position. The major load is applied, then removed while still maintaining the minor load. The difference between depth of penetration before and after application of the major load is used to calculate the Rockwell hardness number. That is, the penetration depth and hardness are inversely proportional. The chief advantage of Rockwell hardness is its ability to display hardness values directly. The result is a dimensionless number noted as HRA, HRB, HRC, etc., where the last letter is the respective Rockwell scale.

The Rockwell C test is performed with a Brale penetrator (120°diamond cone) and a major load of 150kg.

 

References:
Materials Science:

U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 2 and 2. January 1993.
William D. Callister, David G. Rethwisch. Materials Science and Engineering: An Introduction 9th Edition, Wiley; 9 edition (December 4, 2013), ISBN-13: 978-1118324578.
Eberhart, Mark (2003). Why Things Break: Understanding the World by the Way It Comes Apart. Harmony. ISBN 978-1-4000-4760-4.
Gaskell, David R. (1995). Introduction to the thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. ISBN 978-1-56032-992-3.
González-Viñas, W. & Mancini, H.L. (2004). An Introduction to Materials Science. Princeton University Press. ISBN 978-0-691-07097-1.
Ashby, Michael; Hugh Shercliff; David Cebon (2007). Materials: engineering, science, processing and design (1st ed.). Butterworth-Heinemann. ISBN 978-0-7506-8391-3.
J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.

See above:
High-speed Steel

We hope, this article, Hardness of High-speed Steel, helps you. If so, give us a like in the sidebar. Main purpose of this website is to help the public to learn some interesting and important information about materials and their properties.

What is High-speed Steel – HSS – Definition

High-speed steels, abbreviated as HSS, are a specialized class of tool steels that were named primarily for their ability to machine and cut materials at high speeds (high hot hardness).
High speed steel
High speed steel (HSS) is a tool steel with high hardness, high wear resistance and high heat resistance. High-speed steel is often used in power-saw blades and drill bits.

High-speed steels, abbreviated as HSS, are a specialized class of tool steels that were named primarily for their ability to machine and cut materials at high speeds (high hot hardness). It is often used in power-saw blades and drill bits. High-speed steel is superior to the older high-carbon steel tools in that it can withstand higher temperatures without losing its temper (hardness). High-speed steels are complex iron-base alloys of carbon, chromium, vanadium, molybdenum, or tungsten, or combinations there of. To achieve good cutting performance from HSS, an appropriate hardening response must be provided in heat treatment.

Central to the performance of high-speed steels is the hardening response achieved during the heat treatment process. Alloying elements are introduced in quantities given by the  intended application and by their function in the heat treatment process, whether to increase the solidus temperature or inhibit the growth of secondary hardening precipitates, enabling higher operating temperature.

High-speed Steel – AISI M2

For example, molybdenum high-speed steel – AISI M2 is the “standard” and most widely used industrial HSS. Molybdenum high speed steels are designated as Group M steels according to the AISI classification system. M2 HSS has small and evenly distributed carbides giving high wear resistance, though its decarburization sensitivity is a little bit high. It is usually used to manufacture a variety of tools, such as drill bits, taps and reamers.

high speed steel properties density strength price

Summary

Name High-speed steel
Phase at STP N/A
Density 78160 kg/m3
Ultimate Tensile Strength 1200 MPa
Yield Strength 1000 MPa
Young’s Modulus of Elasticity 200 GPa
Brinell Hardness 720 BHN
Melting Point 1430 °C
Thermal Conductivity 41 W/mK
Heat Capacity 470 J/g K
Price 8 $/kg

The carbon and alloy contents are balanced at sufficient levels to provide high attainable hardening response, excellent wear resistance, high resistance to the softening effects of elevated temperature, and good toughness for effective use in industrial cutting applications. Titanium nitride (an extremely hard ceramic material), or titanium carbide coatings can be used in the tools made of this kind of steels through physical vapor deposition process to improve the performance and life span of the tool. TiN has a Vickers hardness of 1800–2100 and it has metallic gold color.

M2 high-speed steel

84%Iron in Periodic Table

6%Tungsten in Periodic Table

5%Molybdenum in Periodic Table

Alloying Agents in High-speed Steels

High-speed steel - M8
High-speed steel – M8

Pure iron is too soft to be used for the purpose of structure, but the addition of small quantities of other elements (carbon, manganese or silicon for instance) greatly increases its mechanical strength. The synergistic effect of alloying elements and heat treatment produces a tremendous variety of microstructures and properties. The four major alloying elements that form carbides in high-speed steels are: tungsten, chromium, vanadium and molybdenum. These alloying elements combine with carbon to form very hard and wear-resistant carbide compounds. The microstructure of high-speed steels consists of a martensitic matrix with a dispersion of two sets of carbides. These carbides are usually known as primary and secondary carbides. Primary carbides are those carbides formed during solidification of the steel. Secondary carbides are those carbides formed during secondary hardening heat-treatment of the steels.

  • Tungsten. Produces stable carbides and refines grain size so as to increase hardness, particularly at high temperatures. Tungsten is used extensively in high-speed tool steels and has been proposed as a substitute for molybdenum in reduced-activation ferritic steels for nuclear applications. The addition of about 10% of tungsten and molybdenum in total maximises efficiently the hardness and toughness of high speed steels and maintains those properties at the high temperatures generated when cutting metals. Tungsten and molybdenum are  interchangeable at an atomic level and both promote resistance to tempering which gives improved tool cutting performance at higher   temperatures.
  • Chromium. Chromium increases hardness, strength, and corrosion resistance. The strengthening effect of forming stable metal carbides at the grain boundaries and the strong increase in corrosion resistance made chromium an important alloying material for steel. Generally speaking, the concentration specified for most grades is approximately 4%. This level appears to result in the best balance between hardness and toughness. Chromium plays an important role in the hardening mechanism and is considered irreplaceable. At higher temperatures, chromium contributes increased strength. It is ordinarily used for applications of this nature in conjunction with molybdenum.
  • Molybdenum. Molybdenum (about 0.50-8.00%) when added to a tool steel makes it more resistant to high temperature. Molybdenum increases hardenability and strength, particularly at high temperatures due to the high melting point of molybdenum. Molybdenum is unique in the extent to which it increases the high-temperature tensile and creep strengths of steel. It retards the transformation of austenite to pearlite far more than it does the transformation of austenite to bainite; thus, bainite may be produced by continuous cooling of molybdenum-containing steels.
  • Vanadium. Vanadium is generally added to steel to inhibit grain growth during heat treatment. In controlling grain growth, it improves both the strength and toughness of hardened and tempered steels. The size of the grain determines the properties of the metal. For example, smaller grain size increases tensile strength and tends to increase ductility. A larger grain size is preferred for improved high-temperature creep properties. Vanadium is added to promote abrasion resistance and to produce hard and stable carbides which being only partly soluble, release little carbon into the matrix.

Properties of Molybdenum High-speed Steel – AISI M2

Material properties are intensive properties, that means they are independent of the amount of mass and may vary from place to place within the system at any moment. The basis of materials science involves studying the structure of materials, and relating them to their properties (mechanical, electrical etc.). Once a materials scientist knows about this structure-property correlation, they can then go on to study the relative performance of a material in a given application. The major determinants of the structure of a material and thus of its properties are its constituent chemical elements and the way in which it has been processed into its final form.

Mechanical Properties of High-speed Steel – AISI M2

Materials are frequently chosen for various applications because they have desirable combinations of mechanical characteristics. For structural applications, material properties are crucial and engineers must take them into account.

Strength of High-speed Steel – AISI M2

In mechanics of materials, the strength of a material is its ability to withstand an applied load without failure or plastic deformation. Strength of materials basically considers the relationship between the external loads applied to a material and the resulting deformation or change in material dimensions. Strength of a material is its ability to withstand this applied load without failure or plastic deformation.

Ultimate Tensile Strength

Ultimate tensile strength of high-speed steel – AISI M2 depends on heat treatment process, but it is about 1200 MPa.

Yield Strength - Ultimate Tensile Strength - Table of MaterialsThe ultimate tensile strength is the maximum on the engineering stress-strain curve. This corresponds to the maximum stress that can be sustained by a structure in tension. Ultimate tensile strength is often shortened to “tensile strength” or even to “the ultimate.”  If this stress is applied and maintained, fracture will result. Often, this value is significantly more than the yield stress (as much as 50 to 60 percent more than the yield for some types of metals). When a ductile material reaches its ultimate strength, it experiences necking where the cross-sectional area reduces locally. The stress-strain curve contains no higher stress than the ultimate strength. Even though deformations can continue to increase, the stress usually decreases after the ultimate strength has been achieved. It is an intensive property; therefore its value does not depend on the size of the test specimen. However, it is dependent on other factors, such as the preparation of the specimen, the presence or otherwise of surface defects, and the temperature of the test environment and material. Ultimate tensile strengths vary from 50 MPa for an aluminum to as high as 3000 MPa for very high-strength steels.

Yield Strength

Yield strength of high-speed steel – AISI M2 depends on heat treatment process, but it is about 1000 MPa. Compressive yield strength is about 3250 Mpa.

The yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning plastic behavior. Yield strength or yield stress is the material property defined as the stress at which a material begins to deform plastically whereas yield point is the point where nonlinear (elastic + plastic) deformation begins. Prior to the yield point, the material will deform elastically and will return to its original shape when the applied stress is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible. Some steels and other materials exhibit a behaviour termed a yield point phenomenon. Yield strengths vary from 35 MPa for a low-strength aluminum to greater than 1400 MPa for very high-strength steels.

Young’s Modulus of Elasticity

Young’s modulus of elasticity of high-speed steel – AISI M2 is 200 GPa.

The Young’s modulus of elasticity is the elastic modulus for tensile and compressive stress in the linear elasticity regime of a uniaxial deformation and is usually assessed by tensile tests. Up to a limiting stress, a body will be able to recover its dimensions on removal of the load. The applied stresses cause the atoms in a crystal to move from their equilibrium position. All the atoms are displaced the same amount and still maintain their relative geometry. When the stresses are removed, all the atoms return to their original positions and no permanent deformation occurs. According to the Hooke’s law, the stress is proportional to the strain (in the elastic region), and the slope is Young’s modulus. Young’s modulus is equal to the longitudinal stress divided by the strain.

Hardness of High-speed Steel – AISI M2

Rockwell hardness of high-speed steel – AISI M2 depends on heat treatment process, but it is approximately 65 HRC.

Brinell hardness number

Rockwell hardness test is one of the most common indentation hardness tests, that has been developed for hardness testing. In contrast to Brinell test, the Rockwell tester measures the depth of penetration of an indenter under a large load (major load) compared to the penetration made by a preload (minor load). The minor load establishes the zero position. The major load is applied, then removed while still maintaining the minor load. The difference between depth of penetration before and after application of the major load is used to calculate the Rockwell hardness number. That is, the penetration depth and hardness are inversely proportional. The chief advantage of Rockwell hardness is its ability to display hardness values directly. The result is a dimensionless number noted as HRA, HRB, HRC, etc., where the last letter is the respective Rockwell scale.

The Rockwell C test is performed with a Brale penetrator (120°diamond cone) and a major load of 150kg.

Thermal Properties of High-speed Steel – AISI M2

Thermal properties of materials refer to the response of materials to changes in their thermodynamics/thermodynamic-properties/what-is-temperature-physics/”>temperature and to the application of heat. As a solid absorbs thermodynamics/what-is-energy-physics/”>energy in the form of heat, its temperature rises and its dimensions increase. But different materials react to the application of heat differently.

Heat capacity, thermal expansion, and thermal conductivity are properties that are often critical in the practical use of solids.

Melting Point of High-speed Steel – AISI M2

Melting point of high-speed steel – AISI M2 steel is around 1430°C.

In general, melting is a phase change of a substance from the solid to the liquid phase. The melting point of a substance is the temperature at which this phase change occurs. The melting point also defines a condition in which the solid and liquid can exist in equilibrium.

Thermal Conductivity of High-speed Steel – AISI M2

The thermal conductivity of high-speed steel – AISI M2 is 41 W/(m.K).

The heat transfer characteristics of a solid material are measured by a property called the thermal conductivity, k (or λ), measured in W/m.K. It is a measure of a substance’s ability to transfer heat through a material by conduction. Note that Fourier’s law applies for all matter, regardless of its state (solid, liquid, or gas), therefore, it is also defined for liquids and gases.

The thermal conductivity of most liquids and solids varies with temperature. For vapors, it also depends upon pressure. In general:

thermal conductivity - definition

Most materials are very nearly homogeneous, therefore we can usually write k = k (T). Similar definitions are associated with thermal conductivities in the y- and z-directions (ky, kz), but for an isotropic material the thermal conductivity is independent of the direction of transfer, kx = ky = kz = k.

[/lgc_column]
References:
Materials Science:

U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 2 and 2. January 1993.
William D. Callister, David G. Rethwisch. Materials Science and Engineering: An Introduction 9th Edition, Wiley; 9 edition (December 4, 2013), ISBN-13: 978-1118324578.
Eberhart, Mark (2003). Why Things Break: Understanding the World by the Way It Comes Apart. Harmony. ISBN 978-1-4000-4760-4.
Gaskell, David R. (1995). Introduction to the thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. ISBN 978-1-56032-992-3.
González-Viñas, W. & Mancini, H.L. (2004). An Introduction to Materials Science. Princeton University Press. ISBN 978-0-691-07097-1.
Ashby, Michael; Hugh Shercliff; David Cebon (2007). Materials: engineering, science, processing and design (1st ed.). Butterworth-Heinemann. ISBN 978-0-7506-8391-3.
J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.

See above:
Steel

We hope, this article, High-speed Steel – HSS, helps you. If so, give us a like in the sidebar. Main purpose of this website is to help the public to learn some interesting and important information about materials and their properties.

What are Properties of Molybdenum High-speed Steel – AISI M2 – Definition

Molybdenum high-speed steel – AISI M2 is the “standard” and most widely used industrial HSS. M2 HSS has small and evenly distributed carbides giving high wear resistance, though its decarburization sensitivity is a little bit high. Properties of Molybdenum High-speed Steel
High speed steel
High speed steel (HSS) is a tool steel with high hardness, high wear resistance and high heat resistance. High-speed steel is often used in power-saw blades and drill bits.

Molybdenum high-speed steel – AISI M2 is the “standard” and most widely used industrial HSS. Molybdenum high speed steels are designated as Group M steels according to the AISI classification system. M2 HSS has small and evenly distributed carbides giving high wear resistance, though its decarburization sensitivity is a little bit high. It is usually used to manufacture a variety of tools, such as drill bits, taps and reamers.

The carbon and alloy contents are balanced at sufficient levels to provide high attainable hardening response, excellent wear resistance, high resistance to the softening effects of elevated temperature, and good toughness for effective use in industrial cutting applications. Titanium nitride (an extremely hard ceramic material), or titanium carbide coatings can be used in the tools made of this kind of steels through physical vapor deposition process to improve the performance and life span of the tool. TiN has a Vickers hardness of 1800–2100 and it has metallic gold color.

M2 high-speed steel

Properties of Molybdenum High-speed Steel – AISI M2

Material properties are intensive properties, that means they are independent of the amount of mass and may vary from place to place within the system at any moment. The basis of materials science involves studying the structure of materials, and relating them to their properties (mechanical, electrical etc.). Once a materials scientist knows about this structure-property correlation, they can then go on to study the relative performance of a material in a given application. The major determinants of the structure of a material and thus of its properties are its constituent chemical elements and the way in which it has been processed into its final form.

Mechanical Properties of High-speed Steel – AISI M2

Materials are frequently chosen for various applications because they have desirable combinations of mechanical characteristics. For structural applications, material properties are crucial and engineers must take them into account.

Strength of High-speed Steel – AISI M2

In mechanics of materials, the strength of a material is its ability to withstand an applied load without failure or plastic deformation. Strength of materials basically considers the relationship between the external loads applied to a material and the resulting deformation or change in material dimensions. Strength of a material is its ability to withstand this applied load without failure or plastic deformation.

Ultimate Tensile Strength

Ultimate tensile strength of high-speed steel – AISI M2 depends on heat treatment process, but it is about 1200 MPa.

Yield Strength - Ultimate Tensile Strength - Table of MaterialsThe ultimate tensile strength is the maximum on the engineering stress-strain curve. This corresponds to the maximum stress that can be sustained by a structure in tension. Ultimate tensile strength is often shortened to “tensile strength” or even to “the ultimate.”  If this stress is applied and maintained, fracture will result. Often, this value is significantly more than the yield stress (as much as 50 to 60 percent more than the yield for some types of metals). When a ductile material reaches its ultimate strength, it experiences necking where the cross-sectional area reduces locally. The stress-strain curve contains no higher stress than the ultimate strength. Even though deformations can continue to increase, the stress usually decreases after the ultimate strength has been achieved. It is an intensive property; therefore its value does not depend on the size of the test specimen. However, it is dependent on other factors, such as the preparation of the specimen, the presence or otherwise of surface defects, and the temperature of the test environment and material. Ultimate tensile strengths vary from 50 MPa for an aluminum to as high as 3000 MPa for very high-strength steels.

Yield Strength

Yield strength of high-speed steel – AISI M2 depends on heat treatment process, but it is about 1000 MPa. Compressive yield strength is about 3250 Mpa.

The yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning plastic behavior. Yield strength or yield stress is the material property defined as the stress at which a material begins to deform plastically whereas yield point is the point where nonlinear (elastic + plastic) deformation begins. Prior to the yield point, the material will deform elastically and will return to its original shape when the applied stress is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible. Some steels and other materials exhibit a behaviour termed a yield point phenomenon. Yield strengths vary from 35 MPa for a low-strength aluminum to greater than 1400 MPa for very high-strength steels.

Young’s Modulus of Elasticity

Young’s modulus of elasticity of high-speed steel – AISI M2 is 200 GPa.

The Young’s modulus of elasticity is the elastic modulus for tensile and compressive stress in the linear elasticity regime of a uniaxial deformation and is usually assessed by tensile tests. Up to a limiting stress, a body will be able to recover its dimensions on removal of the load. The applied stresses cause the atoms in a crystal to move from their equilibrium position. All the atoms are displaced the same amount and still maintain their relative geometry. When the stresses are removed, all the atoms return to their original positions and no permanent deformation occurs. According to the Hooke’s law, the stress is proportional to the strain (in the elastic region), and the slope is Young’s modulus. Young’s modulus is equal to the longitudinal stress divided by the strain.

Hardness of High-speed Steel – AISI M2

Rockwell hardness of high-speed steel – AISI M2 depends on heat treatment process, but it is approximately 65 HRC.

Brinell hardness number

Rockwell hardness test is one of the most common indentation hardness tests, that has been developed for hardness testing. In contrast to Brinell test, the Rockwell tester measures the depth of penetration of an indenter under a large load (major load) compared to the penetration made by a preload (minor load). The minor load establishes the zero position. The major load is applied, then removed while still maintaining the minor load. The difference between depth of penetration before and after application of the major load is used to calculate the Rockwell hardness number. That is, the penetration depth and hardness are inversely proportional. The chief advantage of Rockwell hardness is its ability to display hardness values directly. The result is a dimensionless number noted as HRA, HRB, HRC, etc., where the last letter is the respective Rockwell scale.

The Rockwell C test is performed with a Brale penetrator (120°diamond cone) and a major load of 150kg.

Thermal Properties of High-speed Steel – AISI M2

Thermal properties of materials refer to the response of materials to changes in their thermodynamics/thermodynamic-properties/what-is-temperature-physics/”>temperature and to the application of heat. As a solid absorbs thermodynamics/what-is-energy-physics/”>energy in the form of heat, its temperature rises and its dimensions increase. But different materials react to the application of heat differently.

Heat capacity, thermal expansion, and thermal conductivity are properties that are often critical in the practical use of solids.

Melting Point of High-speed Steel – AISI M2

Melting point of high-speed steel – AISI M2 steel is around 1430°C.

In general, melting is a phase change of a substance from the solid to the liquid phase. The melting point of a substance is the temperature at which this phase change occurs. The melting point also defines a condition in which the solid and liquid can exist in equilibrium.

Thermal Conductivity of High-speed Steel – AISI M2

The thermal conductivity of high-speed steel – AISI M2 is 41 W/(m.K).

The heat transfer characteristics of a solid material are measured by a property called the thermal conductivity, k (or λ), measured in W/m.K. It is a measure of a substance’s ability to transfer heat through a material by conduction. Note that Fourier’s law applies for all matter, regardless of its state (solid, liquid, or gas), therefore, it is also defined for liquids and gases.

The thermal conductivity of most liquids and solids varies with temperature. For vapors, it also depends upon pressure. In general:

thermal conductivity - definition

Most materials are very nearly homogeneous, therefore we can usually write k = k (T). Similar definitions are associated with thermal conductivities in the y- and z-directions (ky, kz), but for an isotropic material the thermal conductivity is independent of the direction of transfer, kx = ky = kz = k.

References:
Materials Science:

U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 2 and 2. January 1993.
William D. Callister, David G. Rethwisch. Materials Science and Engineering: An Introduction 9th Edition, Wiley; 9 edition (December 4, 2013), ISBN-13: 978-1118324578.
Eberhart, Mark (2003). Why Things Break: Understanding the World by the Way It Comes Apart. Harmony. ISBN 978-1-4000-4760-4.
Gaskell, David R. (1995). Introduction to the thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. ISBN 978-1-56032-992-3.
González-Viñas, W. & Mancini, H.L. (2004). An Introduction to Materials Science. Princeton University Press. ISBN 978-0-691-07097-1.
Ashby, Michael; Hugh Shercliff; David Cebon (2007). Materials: engineering, science, processing and design (1st ed.). Butterworth-Heinemann. ISBN 978-0-7506-8391-3.
J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.

See above:
High-speed Steel

We hope, this article, Properties of Molybdenum High-speed Steel – AISI M2, helps you. If so, give us a like in the sidebar. Main purpose of this website is to help the public to learn some interesting and important information about materials and their properties.

What is Hardness of Tool Steel – Definition

Rockwell hardness of tool steel – A2 steel depends on heat treatment process, but it is approximately 60 HRC. Hardness of Tool Steel
Tool steel
Tool steel refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools.

Tool steel refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools (punches, dies, molds, tools for cutting, blanking, forming, drawing, steering and slitting tools). Their suitability comes from their distinctive hardness, resistance to abrasion and deformation, and their ability to hold a cutting edge at elevated temperatures. With a carbon content between 0.5% and 1.5%, tool steels are manufactured under carefully controlled conditions to produce the required quality. The presence of carbides in their matrix plays the dominant role in the qualities of tool steel.

They are generally grouped into two classes:

  • Plain carbon steels containing a high percentage of carbon, about 0.80-1.50%
  • Alloy tool steels, in which other elements (chromium, molybdenum, vanadium, tungsten and cobalt) are added to provide greater strength, toughness, corrosion and heat resistance of steel.

One of subgroups of tool steels is high-speed steels (HSS), which were named primarily for their ability to machine and cut materials at high speeds (high hot hardness). It is often used in power-saw blades and drill bits. This group of tool steels is described in a separate article.

Example of Tool Steel – A2 Steel

A2 tool steel is an air hardening, cold work steel of group A steels containing molybdenum and chromium. A2 steel contains 5% of chromium steel which provides high hardness after heat treatment with good dimensional stability. The carbon content in A2 tool steels is high. A2 offers good toughness with medium wear resistance and is relatively easy to machine. A2 tool steel can be used in many applications which require good wear resistance as well as good toughness. Typical applications for A2 steel:

  • Forming dies
  • Slitters
  • Gauges
  • Shear blades
  • Blanking tools
  • Punch dies

A2 tool steel

Hardness of Tool Steel – A2 Steel

Rockwell hardness of tool steel – A2 steel depends on heat treatment process, but it is approximately 60 HRC.

Brinell hardness number

Rockwell hardness test is one of the most common indentation hardness tests, that has been developed for hardness testing. In contrast to Brinell test, the Rockwell tester measures the depth of penetration of an indenter under a large load (major load) compared to the penetration made by a preload (minor load). The minor load establishes the zero position. The major load is applied, then removed while still maintaining the minor load. The difference between depth of penetration before and after application of the major load is used to calculate the Rockwell hardness number. That is, the penetration depth and hardness are inversely proportional. The chief advantage of Rockwell hardness is its ability to display hardness values directly. The result is a dimensionless number noted as HRA, HRB, HRC, etc., where the last letter is the respective Rockwell scale.

The Rockwell C test is performed with a Brale penetrator (120°diamond cone) and a major load of 150kg.

 

References:
Materials Science:

U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 2 and 2. January 1993.
William D. Callister, David G. Rethwisch. Materials Science and Engineering: An Introduction 9th Edition, Wiley; 9 edition (December 4, 2013), ISBN-13: 978-1118324578.
Eberhart, Mark (2003). Why Things Break: Understanding the World by the Way It Comes Apart. Harmony. ISBN 978-1-4000-4760-4.
Gaskell, David R. (1995). Introduction to the thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. ISBN 978-1-56032-992-3.
González-Viñas, W. & Mancini, H.L. (2004). An Introduction to Materials Science. Princeton University Press. ISBN 978-0-691-07097-1.
Ashby, Michael; Hugh Shercliff; David Cebon (2007). Materials: engineering, science, processing and design (1st ed.). Butterworth-Heinemann. ISBN 978-0-7506-8391-3.
J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.

See above:
Tool Steel

We hope, this article, Hardness of Tool Steel, helps you. If so, give us a like in the sidebar. Main purpose of this website is to help the public to learn some interesting and important information about materials and their properties.

What is Composition of Tool Steel – Definition

Tool steel usually contains a high percentage of carbon, about 0.80-1.50%. Alloy tool steel contains 5% of chromium which provides high hardness after heat treatment with good dimensional stability.
Tool steel
Tool steel refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools.

Tool steel refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools (punches, dies, molds, tools for cutting, blanking, forming, drawing, steering and slitting tools). Their suitability comes from their distinctive hardness, resistance to abrasion and deformation, and their ability to hold a cutting edge at elevated temperatures. With a carbon content between 0.5% and 1.5%, tool steels are manufactured under carefully controlled conditions to produce the required quality. The presence of carbides in their matrix plays the dominant role in the qualities of tool steel.

They are generally grouped into two classes:

  • Plain carbon steels containing a high percentage of carbon, about 0.80-1.50%
  • Alloy tool steels, in which other elements (chromium, molybdenum, vanadium, tungsten and cobalt) are added to provide greater strength, toughness, corrosion and heat resistance of steel.

One of subgroups of tool steels is high-speed steels (HSS), which were named primarily for their ability to machine and cut materials at high speeds (high hot hardness). It is often used in power-saw blades and drill bits. This group of tool steels is described in a separate article.

Composition of Tool Steel – A2 Steel

A2 tool steel is an air hardening, cold work steel of group A steels containing molybdenum and chromium. A2 steel contains 5% of chromium steel which provides high hardness after heat treatment with good dimensional stability. The carbon content in A2 tool steels is high. A2 offers good toughness with medium wear resistance and is relatively easy to machine. A2 tool steel can be used in many applications which require good wear resistance as well as good toughness. Typical applications for A2 steel:

  • Forming dies
  • Slitters
  • Gauges
  • Shear blades
  • Blanking tools
  • Punch dies

A2 tool steel

References:
Materials Science:

U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 2 and 2. January 1993.
William D. Callister, David G. Rethwisch. Materials Science and Engineering: An Introduction 9th Edition, Wiley; 9 edition (December 4, 2013), ISBN-13: 978-1118324578.
Eberhart, Mark (2003). Why Things Break: Understanding the World by the Way It Comes Apart. Harmony. ISBN 978-1-4000-4760-4.
Gaskell, David R. (1995). Introduction to the thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. ISBN 978-1-56032-992-3.
González-Viñas, W. & Mancini, H.L. (2004). An Introduction to Materials Science. Princeton University Press. ISBN 978-0-691-07097-1.
Ashby, Michael; Hugh Shercliff; David Cebon (2007). Materials: engineering, science, processing and design (1st ed.). Butterworth-Heinemann. ISBN 978-0-7506-8391-3.
J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.

See above:
Tool Steel

We hope, this article, Composition of Tool Steel, helps you. If so, give us a like in the sidebar. Main purpose of this website is to help the public to learn some interesting and important information about materials and their properties.

What are Properties of Tool Steel – A2 Steel – Definition

A2 tool steel is an air hardening, cold work steel of group A steels containing molybdenum and chromium. Properties of Tool Steel
Tool steel
Tool steel refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools.

A2 tool steel is an air hardening, cold work steel of group A steels containing molybdenum and chromium. A2 steel contains 5% of chromium steel which provides high hardness after heat treatment with good dimensional stability. The carbon content in A2 tool steels is high. A2 offers good toughness with medium wear resistance and is relatively easy to machine. A2 tool steel can be used in many applications which require good wear resistance as well as good toughness. Typical applications for A2 steel:

  • Forming dies
  • Slitters
  • Gauges
  • Shear blades
  • Blanking tools
  • Punch dies

A2 tool steel

Properties of Tool Steel – A2 Steel

Material properties are intensive properties, that means they are independent of the amount of mass and may vary from place to place within the system at any moment. The basis of materials science involves studying the structure of materials, and relating them to their properties (mechanical, electrical etc.). Once a materials scientist knows about this structure-property correlation, they can then go on to study the relative performance of a material in a given application. The major determinants of the structure of a material and thus of its properties are its constituent chemical elements and the way in which it has been processed into its final form.

Mechanical Properties of Tool Steel – A2 Steel

Materials are frequently chosen for various applications because they have desirable combinations of mechanical characteristics. For structural applications, material properties are crucial and engineers must take them into account.

Strength of Tool Steel – A2 Steel

In mechanics of materials, the strength of a material is its ability to withstand an applied load without failure or plastic deformation. Strength of materials basically considers the relationship between the external loads applied to a material and the resulting deformation or change in material dimensions. Strength of a material is its ability to withstand this applied load without failure or plastic deformation.

Ultimate Tensile Strength

Ultimate tensile strength of tool steel – A2 steel depends on heat treatment process, but it is about 1860 MPa.

Yield Strength - Ultimate Tensile Strength - Table of MaterialsThe ultimate tensile strength is the maximum on the engineering stress-strain curve. This corresponds to the maximum stress that can be sustained by a structure in tension. Ultimate tensile strength is often shortened to “tensile strength” or even to “the ultimate.”  If this stress is applied and maintained, fracture will result. Often, this value is significantly more than the yield stress (as much as 50 to 60 percent more than the yield for some types of metals). When a ductile material reaches its ultimate strength, it experiences necking where the cross-sectional area reduces locally. The stress-strain curve contains no higher stress than the ultimate strength. Even though deformations can continue to increase, the stress usually decreases after the ultimate strength has been achieved. It is an intensive property; therefore its value does not depend on the size of the test specimen. However, it is dependent on other factors, such as the preparation of the specimen, the presence or otherwise of surface defects, and the temperature of the test environment and material. Ultimate tensile strengths vary from 50 MPa for an aluminum to as high as 3000 MPa for very high-strength steels.

Yield Strength

Yield strength of tool steel – A2 steel depends on heat treatment process, but it is about 1400 MPa.

The yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning plastic behavior. Yield strength or yield stress is the material property defined as the stress at which a material begins to deform plastically whereas yield point is the point where nonlinear (elastic + plastic) deformation begins. Prior to the yield point, the material will deform elastically and will return to its original shape when the applied stress is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible. Some steels and other materials exhibit a behaviour termed a yield point phenomenon. Yield strengths vary from 35 MPa for a low-strength aluminum to greater than 1400 MPa for very high-strength steels.

Young’s Modulus of Elasticity

Young’s modulus of elasticity of tool steel – A2 steel is 200 GPa.

The Young’s modulus of elasticity is the elastic modulus for tensile and compressive stress in the linear elasticity regime of a uniaxial deformation and is usually assessed by tensile tests. Up to a limiting stress, a body will be able to recover its dimensions on removal of the load. The applied stresses cause the atoms in a crystal to move from their equilibrium position. All the atoms are displaced the same amount and still maintain their relative geometry. When the stresses are removed, all the atoms return to their original positions and no permanent deformation occurs. According to the Hooke’s law, the stress is proportional to the strain (in the elastic region), and the slope is Young’s modulus. Young’s modulus is equal to the longitudinal stress divided by the strain.

Hardness of Tool Steel – A2 Steel

Rockwell hardness of tool steel – A2 steel depends on heat treatment process, but it is approximately 60 HRC.

Brinell hardness number

Rockwell hardness test is one of the most common indentation hardness tests, that has been developed for hardness testing. In contrast to Brinell test, the Rockwell tester measures the depth of penetration of an indenter under a large load (major load) compared to the penetration made by a preload (minor load). The minor load establishes the zero position. The major load is applied, then removed while still maintaining the minor load. The difference between depth of penetration before and after application of the major load is used to calculate the Rockwell hardness number. That is, the penetration depth and hardness are inversely proportional. The chief advantage of Rockwell hardness is its ability to display hardness values directly. The result is a dimensionless number noted as HRA, HRB, HRC, etc., where the last letter is the respective Rockwell scale.

The Rockwell C test is performed with a Brale penetrator (120°diamond cone) and a major load of 150kg.

Thermal Properties of Tool Steel – A2 Steel

Thermal properties of materials refer to the response of materials to changes in their thermodynamics/thermodynamic-properties/what-is-temperature-physics/”>temperature and to the application of heat. As a solid absorbs thermodynamics/what-is-energy-physics/”>energy in the form of heat, its temperature rises and its dimensions increase. But different materials react to the application of heat differently.

Heat capacity, thermal expansion, and thermal conductivity are properties that are often critical in the practical use of solids.

Melting Point of Tool Steel – A2 Steel

Melting point of tool steel – A2 steel is around 1420°C.

In general, melting is a phase change of a substance from the solid to the liquid phase. The melting point of a substance is the temperature at which this phase change occurs. The melting point also defines a condition in which the solid and liquid can exist in equilibrium.

Thermal Conductivity of Tool Steel – A2 Steel

The thermal conductivity of tool steel – A2 steel is 26 W/(m.K).

The heat transfer characteristics of a solid material are measured by a property called the thermal conductivity, k (or λ), measured in W/m.K. It is a measure of a substance’s ability to transfer heat through a material by conduction. Note that Fourier’s law applies for all matter, regardless of its state (solid, liquid, or gas), therefore, it is also defined for liquids and gases.

The thermal conductivity of most liquids and solids varies with temperature. For vapors, it also depends upon pressure. In general:

thermal conductivity - definition

Most materials are very nearly homogeneous, therefore we can usually write k = k (T). Similar definitions are associated with thermal conductivities in the y- and z-directions (ky, kz), but for an isotropic material the thermal conductivity is independent of the direction of transfer, kx = ky = kz = k.

References:
Materials Science:

U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 2 and 2. January 1993.
William D. Callister, David G. Rethwisch. Materials Science and Engineering: An Introduction 9th Edition, Wiley; 9 edition (December 4, 2013), ISBN-13: 978-1118324578.
Eberhart, Mark (2003). Why Things Break: Understanding the World by the Way It Comes Apart. Harmony. ISBN 978-1-4000-4760-4.
Gaskell, David R. (1995). Introduction to the thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. ISBN 978-1-56032-992-3.
González-Viñas, W. & Mancini, H.L. (2004). An Introduction to Materials Science. Princeton University Press. ISBN 978-0-691-07097-1.
Ashby, Michael; Hugh Shercliff; David Cebon (2007). Materials: engineering, science, processing and design (1st ed.). Butterworth-Heinemann. ISBN 978-0-7506-8391-3.
J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.

See above:
Tool Steel

We hope, this article, Properties of Tool Steel – A2 Steel, helps you. If so, give us a like in the sidebar. Main purpose of this website is to help the public to learn some interesting and important information about materials and their properties.

What is Strength of Tool Steel – Definition

Ultimate tensile strength of tool steel – A2 steel depends on heat treatment process, but it is about 1860 MPa. Strength of Tool Steel
Tool steel
Tool steel refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools.

Tool steel refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools (punches, dies, molds, tools for cutting, blanking, forming, drawing, steering and slitting tools). Their suitability comes from their distinctive hardness, resistance to abrasion and deformation, and their ability to hold a cutting edge at elevated temperatures. With a carbon content between 0.5% and 1.5%, tool steels are manufactured under carefully controlled conditions to produce the required quality. The presence of carbides in their matrix plays the dominant role in the qualities of tool steel.

They are generally grouped into two classes:

  • Plain carbon steels containing a high percentage of carbon, about 0.80-1.50%
  • Alloy tool steels, in which other elements (chromium, molybdenum, vanadium, tungsten and cobalt) are added to provide greater strength, toughness, corrosion and heat resistance of steel.

Example of Tool Steel – A2 Steel

A2 tool steel is an air hardening, cold work steel of group A steels containing molybdenum and chromium. A2 steel contains 5% of chromium steel which provides high hardness after heat treatment with good dimensional stability. The carbon content in A2 tool steels is high. A2 offers good toughness with medium wear resistance and is relatively easy to machine. A2 tool steel can be used in many applications which require good wear resistance as well as good toughness. Typical applications for A2 steel:

  • Forming dies
  • Slitters
  • Gauges
  • Shear blades
  • Blanking tools
  • Punch dies

A2 tool steel

Strength of Tool Steel – A2 Steel

In mechanics of materials, the strength of a material is its ability to withstand an applied load without failure or plastic deformation. Strength of materials basically considers the relationship between the external loads applied to a material and the resulting deformation or change in material dimensions. Strength of a material is its ability to withstand this applied load without failure or plastic deformation.

Ultimate Tensile Strength

Ultimate tensile strength of tool steel – A2 steel depends on heat treatment process, but it is about 1860 MPa.

Yield Strength - Ultimate Tensile Strength - Table of MaterialsThe ultimate tensile strength is the maximum on the engineering stress-strain curve. This corresponds to the maximum stress that can be sustained by a structure in tension. Ultimate tensile strength is often shortened to “tensile strength” or even to “the ultimate.”  If this stress is applied and maintained, fracture will result. Often, this value is significantly more than the yield stress (as much as 50 to 60 percent more than the yield for some types of metals). When a ductile material reaches its ultimate strength, it experiences necking where the cross-sectional area reduces locally. The stress-strain curve contains no higher stress than the ultimate strength. Even though deformations can continue to increase, the stress usually decreases after the ultimate strength has been achieved. It is an intensive property; therefore its value does not depend on the size of the test specimen. However, it is dependent on other factors, such as the preparation of the specimen, the presence or otherwise of surface defects, and the temperature of the test environment and material. Ultimate tensile strengths vary from 50 MPa for an aluminum to as high as 3000 MPa for very high-strength steels.

Yield Strength

Yield strength of tool steel – A2 steel depends on heat treatment process, but it is about 1400 MPa.

The yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning plastic behavior. Yield strength or yield stress is the material property defined as the stress at which a material begins to deform plastically whereas yield point is the point where nonlinear (elastic + plastic) deformation begins. Prior to the yield point, the material will deform elastically and will return to its original shape when the applied stress is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible. Some steels and other materials exhibit a behaviour termed a yield point phenomenon. Yield strengths vary from 35 MPa for a low-strength aluminum to greater than 1400 MPa for very high-strength steels.

Young’s Modulus of Elasticity

Young’s modulus of elasticity of tool steel – A2 steel is 200 GPa.

The Young’s modulus of elasticity is the elastic modulus for tensile and compressive stress in the linear elasticity regime of a uniaxial deformation and is usually assessed by tensile tests. Up to a limiting stress, a body will be able to recover its dimensions on removal of the load. The applied stresses cause the atoms in a crystal to move from their equilibrium position. All the atoms are displaced the same amount and still maintain their relative geometry. When the stresses are removed, all the atoms return to their original positions and no permanent deformation occurs. According to the Hooke’s law, the stress is proportional to the strain (in the elastic region), and the slope is Young’s modulus. Young’s modulus is equal to the longitudinal stress divided by the strain.

References:
Materials Science:

U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 2 and 2. January 1993.
William D. Callister, David G. Rethwisch. Materials Science and Engineering: An Introduction 9th Edition, Wiley; 9 edition (December 4, 2013), ISBN-13: 978-1118324578.
Eberhart, Mark (2003). Why Things Break: Understanding the World by the Way It Comes Apart. Harmony. ISBN 978-1-4000-4760-4.
Gaskell, David R. (1995). Introduction to the thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. ISBN 978-1-56032-992-3.
González-Viñas, W. & Mancini, H.L. (2004). An Introduction to Materials Science. Princeton University Press. ISBN 978-0-691-07097-1.
Ashby, Michael; Hugh Shercliff; David Cebon (2007). Materials: engineering, science, processing and design (1st ed.). Butterworth-Heinemann. ISBN 978-0-7506-8391-3.
J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.

See above:
Tool Steel

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What is Composition of Superalloys – Definition

Composition of Superalloys. Inconel 718 is composed of 55% nickel, 21% chromium, 6% iron, and small amounts of manganese, carbon, and copper.

superalloys - inconel - turbine bladeSuperalloys, or high-performance alloys, are non-ferrous alloys that exhibit outstanding strength and surface stability at high temperatures. Their ability to operate safely at a high fraction of their melting point (up to 85% of their melting points (Tm) expressed in degrees Kelvin, 0.85) is their key characteristics. Superalloys are generally used at temperatures above 540 °C (1000 °F), as at these temperatures ordinary steel and titanium alloys are losing their strengths, also corrosion is common in steels at this temperature. At high temperatures, superalloys retain mechanical strength, resistance to thermal creep deformation, surface stability, and resistance to corrosion or oxidation. Some nickel-based superalloys can withstand temperatures beyond 1200°C, depending on the composition of the alloy.​ Superalloys are often cast as a single crystal, while grain boundaries may provide strength, they decrease creep resistance.

Types of Superalloys

There are three main categories that are jointly called superalloys as mentioned  below. they   posses high level of temperature insensitivity or stability and are widely used as base materials for high temperature applications.

  • Nickel-based Superalloys. Nickel-based superalloys currently constitute over 50% of the weight of advanced aircraft engines. Nickel-base superalloys include solid-solution-strengthened alloys and age-hardenable alloys. Age-hardenable alloys consist of an austenitic (fcc) matrix dispersed with coherent precipitation of an Ni3(Al,Ti) intermetallic with an fcc structure. Ni-based superalloys are alloys with nickel as the primary alloying element are preferred as blade material in the previously discussed applications, rather than Co- or Fe-based superalloys. What is significant for Ni-based superalloys is their high strength, creep and corrosion resistance at high temperatures. It is common to cast turbine blades in directionally solidified form or single-crystal form. Single-crystal blades are mainly used in the first row in the turbine stage.
  • Iron – Nickel-based Superalloys. Fe-based superalloys have showed creep and oxidation resistance similar to that of Ni-based superalloys, while being far less expensive to produce. The most important class of this group are those alloys that are strengthened by an intermetallic compound precipitation in an FCC matrix.
  • Cobalt-based Superalloys. This class of alloys is relatively new. In 2006, Sato et al. discovered a new phase in the Co–Al–W system. Unlike other superalloys, cobalt-base alloys are characterized by a solid-solution-strengthened austenitic (fcc) matrix in which a small quantity of carbide is distributed. While not used commercially to the extent of Ni-based superalloys, alloying elements found in research Co-based alloys are C, Cr, W, Ni, Ti, Al, Ir, and Ta. They possess better weldability and thermal fatigue resistance as compared to nickel based alloy. Moreover, they have excellent corrosion resistance at high temperatures (980-1100 °C) because of their higher chromium contents.

These alloys are generally used at temperature above 450°C, as at these temperatures ordinary steel and titanium alloys are losing their strengths, also corrosion is common in steels at this temperature.

Example – Inconel 718 – Nickel-based Superalloy

In general, Inconel is a registered trademark of Special Metals for a family of austenitic nickel-chromium-based superalloys. Inconel 718 is a nickel-based superalloy that possesses high strength properties and resistance to elevated temperatures. It also demonstrates remarkable protection against corrosion and oxidation. Inconel’s high temperature strength is developed by solid solution strengthening or precipitation hardening, depending on the alloy. Inconel 718 is composed of 55% nickel, 21% chromium, 6% iron, and small amounts of manganese, carbon, and copper.

Common uses of superalloys are in the aerospace and some other high-technology industries. With the combination of corrosion resistance and material strength in the face of extreme heat, this kind of superalloy works well in the nuclear industry. Some nuclear plants use nickel-based superalloys for the reactor core, control rod, and similar parts.​ In nuclear industry, especially low-cobalt superalloys (due to possible activation of cobalt-59) are used. Some of structural parts of nuclear fuel assemblies, such as top and bottom nozzle, may be produced from superalloys such as Inconel. Spacing grids are usually made of a corrosion-resistant material with low absorption cross section for thermal neutrons, usually zirconium alloy (~ 0.18 × 10–24 cm2). First and last spacing grid may be also made of low-cobalt Inconel, which is a superalloy well suited for service in extreme environments subjected to pressure and heat.

Inconel 718

References:
Materials Science:

U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 2 and 2. January 1993.
William D. Callister, David G. Rethwisch. Materials Science and Engineering: An Introduction 9th Edition, Wiley; 9 edition (December 4, 2013), ISBN-13: 978-1118324578.
Eberhart, Mark (2003). Why Things Break: Understanding the World by the Way It Comes Apart. Harmony. ISBN 978-1-4000-4760-4.
Gaskell, David R. (1995). Introduction to the thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. ISBN 978-1-56032-992-3.
González-Viñas, W. & Mancini, H.L. (2004). An Introduction to Materials Science. Princeton University Press. ISBN 978-0-691-07097-1.
Ashby, Michael; Hugh Shercliff; David Cebon (2007). Materials: engineering, science, processing and design (1st ed.). Butterworth-Heinemann. ISBN 978-0-7506-8391-3.
J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.

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Superalloys

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