Metallurgy of Mo in alloy steel & iron

Alloying elements such as chromium, molybdenum, tungsten, etc. are added to carbon steel to improve properties such as hardness, strength and toughness.

The classic methods of strengthening low alloy steels are

  • solution hardening
  • quenching and tempering
  • precipitation hardening
  • controlled rolling

Molybdenum is an effective strengthener in all cases. 

The large majority of low alloy steels are quenched and tempered – Q+T.

From unalloyed Mild Steel to Low Alloy Steel


  • Phase Transformation and Hardenability of Medium Carbon Alloy Steels by W.W. Cias : Climax Molybdenum Company, 1972.
  • Steels; Microstructures and Properties by R.W.K. Honeycombe
  • Functions of the Alloying Elements in Steel by E.C. Bain, ASM 1939
  • Molybdenum’s Place in the Pressure Vessel Field. By R G Dunn, G F Whiteley, W Fairhurst, Climax Molybdenum Company 1970 
  • Steel Deterioration in Hydrogen - What API-sponsored Research has explained. Preprint 63-67, API (May 16, 1967)