There is an important effect of strong toughness and wear resistance of carbon steel, die steel for hot, the increase of the carbon content, strength, hardness and wear resistance increase; but the plasticity and toughness decrease. For cold working die steel, the carbon content increased, the flexural strength and wear resistance increase; reduce the carbon content, toughness increased while the flexural strength and wear resistance decreased, therefore, impact resistance and high toughness cold working die steel carbon content is 0.5%-0.7%, die steel with high abrasion resistance, carbon content 1.2%-2.3%. Carbon can improve the hardenability of steel; but with carbon content increasing, the corrosion resistance of steel decreased, weldability and cold forming performance deterioration.
The effect of chromium Cr
To improve the corrosion resistance of chromium steel and anti-oxidation; increase the hardenability of two hardening effect, the formation of special carbide, improve wear resistance, especially in use and improve the performance of the steel at the same time, without compromising its technical performance; chromium also improve high temperature strength of steel, therefore, chromium is the basic elements of cold work, hot, plastic mold steel.
The effect of molybdenum Mo
The two molybdenum steel to improve the hardening capacity, high temperature strength and creep resistance; improve anti heat sensitivity, hardenability and toughness, brittleness can also inhibit steel; improve corrosion resistance in corrosion resistant plastic die steel, especially the corrosion resistance of oxide in the medium; but the increase tendency of decarburization.
The effect of tungsten W
The role of tungsten molybdenum for similar, forming hard and stable carbides in die steel after quenching and tempering steel, improve the hardness, tungsten reinforced steel wear resistance and anti thermal sensitivity function is better than that of tungsten molybdenum; but increased the toughness of the steel is decreased, the current generation of tungsten in molybdenum tends to improved toughness.
The effect of vanadium V
V strong grain refinement, strong wear resistance and improve two hardening ability and improve anti sensitive; but excessive content will significantly deteriorate the steel forging performance and grinding performance, the vanadium content in steel is about 0.2%-2%.
The effect of nickel Ni
Nickel is the only that can improve the strength and permeability of quenching steel, but also can improve the toughness of the elements, but no contribution to wear resistance and two hardening properties; and obvious deterioration of process performance (ductility, softening and cutting). Therefore, for rarely used in die steel in the cold, but in a large section of the hot die steel and plastic mould steel, adding a small amount of nickel to improve its hardenability and toughness.
The role of manganese Mn
Manganese strongly improve hardenability, reduce Ms, make steel after quenching residual austenite increase, thereby reducing the size of the deformation after quenching. Therefore, Mn is the essential component of air quenching deformation of cold die steel, the main alloy element is high carbon austenitic nonmagnetic steel. Because manganese intensified tempering brittleness and thermal sensitivity, Cr, Mo, V and should therefore be the amount of composite additives; die steel is limited in impact resistance and high toughness cold (Mn = 0.6%-0.8%).
Silicon can strongly improve deformation resistance and impact fatigue resistance of steel, improve the tempering stability and oxidation resistance, but also to a certain extent, reduce the plasticity, toughness and increase the decarburization tendency of steel. In the traditional impact resistant steel, silicon content is 0.5%-2.0%. The silicon content is high, easy to cause the heating process of graphitization of carbon in steel.
The effect of cobalt Co
Cobalt can improve two hardening effect of high speed steel, which increase the red hardness; improve the strength and toughness of maraging steel containing nickel, which has good mechanical properties; heat resistance and heat resistance of cobalt to improve heat resistant steel and hot working die steel.
The effect of sulfur S
Sulfur is a harmful element in steel, sulfur in iron and manganese compounds combine to form FeS, form MnS, will increase the brittleness of steel, reduce the strength and toughness of steel. But in the presence of sulfur in steel, improve the cutting performance of steel, therefore, the development of the sulfur free cutting steel, due to the increased content of sulfur and manganese, manganese sulfide more (MnS), to improve the cutting performance of steel.
The effect of phosphorus P
Phosphorus is a harmful element in steel, increase the brittleness of the steel, especially the low temperature brittleness (Leng Cui), but also improve the sensitivity of temper embrittlement of the steel, when phosphorus and manganese coexist, until the range has high temperature tempering temper brittleness. But phosphorus can improve the strength and corrosion resistance of steel, so the development of the rail steel containing low alloy steel and phosphorus, to improve their corrosion resistance, abrasion resistance and compressive properties.
Kunshan cold die steel