However, for some die steels with high wear resistance and small deformation after quenching, the highest chromium content can reach 13%. In order to form a large number of carbides, the highest carbon content in steel is also high, reaching 2.0%~2.3%. Cold working die steel has high carbon content, and its structure mostly belongs to hypereutectoid steel or ledeburite steel. Commonly used steels include high-carbon low-alloy steel, high-carbon high-chromium steel, chromium-molybdenum steel and medium-carbon chromium-tungsten alloy steel.
Cold rolling die includes cold stamping die, wire drawing die, drawing die, stamping die, winding die, winding plate, cold heading die and cold extrusion die. Steel for cold working dies should have high hardness, strength, wear resistance, sufficient toughness, high hardenability and hardening ability according to the working conditions of the dies manufactured by it.
The alloy tool steel used in this kind of application generally belongs to high carbon alloy steel, and the carbon mass fraction is greater than 0.80%. Chromium is an important alloying element of this kind of steel, and its mass fraction is usually less than 5%.