Chemical Compositions and Grades

The most important alloying elements in hot work tool steels are, in addition to carbon (C), chromium (Cr), tungsten (W), silicon (Si), nickel (Ni), molybdenum (Mo), manganese (Mn), vanadium (V), and cobalt (Co) and they have a significant influence on the transformation behavior during heat treatment and on the technological properties. These alloying elements are quantitatively coordinated so that the desired properties are achieved at the working temperature of the tools. The carbon content is responsible for the hardness increase (achievable hardness increase during hardening) of the steels, while the hardness penetration (penetration depth of the martensitic transformation) and the precipitation hardening (formation of secondary carbides during tempering) depend on the metallic alloying elements.