What is Hardness of High-carbon Steel - Definition

Hardness of High-carbon Steel – AISI 1095 Steel. Brinell hardness of high-carbon steel is approximately 200 MPa. In materials science, hardness is the ability to withstand surface indentation (localized plastic deformation) and scratching.

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

High-carbon steel has approximately 0.60 to 1.00% carbon content. Hardness is higher than the other grades but ductility decreases. They are almost always used in a hardened and tempered condition and, as such, are especially wear resistant and capable of holding a sharp cutting edge. Therefore, high carbon steels could be used for springs, rope wires, hammers, screwdrivers, wrenches and knives. The 10xx series (e.g. 1095 steel) is the most popular choice for carbon steel used in knives as well as katanas. AISI 1095 carbon steel is brittle, and has high hardness and strength. 1095 steel, when used in knives, holds a great edge and is very easy to sharpen. However, the properties of this type of steel give it a tendency to easily rust if not oiled and deliberately cared for.

Hardness of High-carbon Steel – AISI 1095 Steel

Brinell hardness of high-carbon steel is approximately 200 MPa.

In materials science, hardness is the ability to withstand surface indentation (localized plastic deformation) and scratching. Hardness is probably the most poorly defined material property because it may indicate resistance to scratching, resistance to abrasion, resistance to indentation or even resistance to shaping or localized plastic deformation. Hardness is important from an engineering standpoint because resistance to wear by either friction or erosion by steam, oil, and water generally increases with hardness.

Brinell hardness test is one of indentation hardness tests, that has been developed for hardness testing. In Brinell tests, a hard, spherical indenter is forced under a specific load into the surface of the metal to be tested. The typical test uses a 10 mm (0.39 in) diameter hardened steel ball as an indenter with a 3,000 kgf (29.42 kN; 6,614 lbf) force. The load is maintained constant for a specified time (between 10 and 30 s). For softer materials, a smaller force is used; for harder materials, a tungsten carbide ball is substituted for the steel ball.

The test provides numerical results to quantify the hardness of a material, which is expressed by the Brinell hardness number – HB. The Brinell hardness number is designated by the most commonly used test standards (ASTM E10-14[2] and ISO 6506–1:2005) as HBW (H from hardness, B from brinell and W from the material of the indenter, tungsten (wolfram) carbide). In former standards HB or HBS were used to refer to measurements made with steel indenters.

The Brinell hardness number (HB) is the load divided by the surface area of the indentation. The diameter of the impression is measured with a microscope with a superimposed scale. The Brinell hardness number is computed from the equation:

There are a variety of test methods in common use (e.g. Brinell, Knoop, Vickers and Rockwell). There are tables that are available correlating the hardness numbers from the different test methods where correlation is applicable. In all scales, a high hardness number represents a hard metal.

References:

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See above:
High-carbon Steels

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