What is Molybdenum - Alloying Metal - Definition

Found in small quantities in stainless steels, molybdenum increases hardenability and strength, particularly at high temperatures. The high melting point of molybdenum makes it important for giving strength to steel and other metallic alloys at high temperatures.

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. Alloys are usually stronger than pure metals, although they generally offer reduced electrical and thermal conductivity. Strength is the most important criterion by which many structural materials are judged. Therefore, alloys are used for engineering construction. The synergistic effect of alloying elements and heat treatment produces a tremendous variety of microstructures and properties.

Molybdenum. Found in small quantities in stainless steels, molybdenum increases hardenability and strength, particularly at high temperatures. The high melting point of molybdenum makes it important for giving strength to steel and other metallic alloys at high temperatures. 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.

Molybdenum in High-speed Steels

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 thereof. To achieve good cutting performance from HSS, an appropriate hardening response must be provided in heat treatment.

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.

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:
Stainless Steel

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