The range of cold work die steels is very wide, from various carbon tool steels, alloy tool steels, high speed tool steels to powder high speed tool steels and powder high alloy die steels. Cold work die steel is mainly used to manufacture molds for pressing and forming workpieces under cold conditions. Such as: cold blanking die, cold stamping die, cold drawing die, stamping die, cold extrusion die, thread pressing die and powder pressing die. Commonly used cold work die steel SKD11, DC53, SLD and so on.
Cold working die steel has the following characteristics.
1. In terms of use temperature, the use temperature of cold working die steel does not exceed 200~300℃.
2, in terms of specific uses, cold working die steel is mainly used to manufacture a variety of cold stamping die, cold pier die, cold extrusion die and wire drawing die.
3, in terms of load bearing, bearing stamping stress, extrusion stress, tensile stress, bending stress, impact load friction.
4, in terms of performance requirements, cold work die steel has high strength, high hardness, high wear resistance, high fatigue resistance, high bite resistance, enough toughness and small heat treatment deformation.
5, in terms of chemical composition requirements, the content of carbon is high, and the carbon element (mass fraction) required for tough die steel working under impact conditions is generally between 0.50% and 0.70%; The mold requiring high hardness and high wear resistance requires carbon content (mass fraction) between 1.20% and 2.30%, and cr, mn, mo, w, v, nb, si, ti, al, ni, co and other elements are often added to steel. Among them, cr, mn, si, ni, al, co and other elements not only play a role in solid solution strengthening, but also improve the hardenability of steel. Mo, w, v, nb form carbides or composite carbides, refine grains, improve the hardness and wear resistance of steel, improve the tempering stability of steel, and eliminate the tempering brittleness of steel.
6, in terms of organizational requirements, in service organization should be: tempered martensite plus fine granular carbide plus a small amount of residual austenite.
7, in the forging process, it is necessary to express repeatedly in multiple directions, thick and long.
8, in the heat treatment process, often demand annealing, quenching, low temperature tempering and other processes. Sometimes according to the need for surface strengthening treatment, such as nitriding, boron and so on.
