On designing a tool steel, its composition and heat treatment parameters are chosen to provide a hardened and tempered martensitic matrix in which carbides are evenly distributed. In this condition the matrix has an optimum combination of hardness and toughness. The primary carbides provide resistance against abrasive wear and secondary carbides (if any) increase the resistance against plastic deformation. Tool steels are alloyed with carbide forming elements (Typically: vanadium, tungsten, molybdenum and chromium) furthermore some steel types contains cobalt, which respectively raises the temperature at which martensite transformation initiates and at which the transformation is complete. Addition of alloying elements serves primarily two purpose (i) to improve the hardenabillity and (ii) to provide harder and thermally more stable carbides than cementite. Assuming proper heat treatment, the properties of a tool steel strongly depends on which alloying elements are added and their respective concentrations.
|Place of Publication||Roskilde|
|Publisher||Risø National Laboratory|
|Number of pages||25|
|Publication status||Published - 2001|
|Series||Denmark. Forskningscenter Risoe. Risoe-R|