The mold material should have good machinability and easy finishing; it has high heat treatment hardenability, which makes the internal and surface microstructure and properties after quenching uniform, and the dimensional deformation is small; durable high temperature plasticity and thermal fatigue resistance, The mold will not be cracked prematurely; high temperature strength, hardness and high temperature wear resistance, low thermal expansion coefficient, ensuring dimensional stability during mold use; high resistance to liquid die casting alloy chemical erosion and mechanical erosion The ability to prevent mold sticking and melt loss of meat; high high temperature oxidation resistance, normal temperature corrosion resistance, not easy to rust phenomenon.
In order to improve the impact toughness, the chemical purity of the commonly used H13 steel requires: the sulfur content of the superior grade steel is less than 0.005%; the super H13 steel requires less than 0.003% sulfur, and the phosphorus content is less than 0.015%. The grain boundary of steel is free of eutectic carbide inclusions, and the bulk eutectic carbide and impurity intensity are extremely small, which can not resist thermal fatigue and reduce the ductility of steel, which is the origin of crack occurrence. To use the refined steel of electroslag remelting furnace, it not only has high purity, but also has compact structure, excellent thermal fatigue resistance, good thermal crack resistance, excellent toughness and ductility, excellent polishing property, and good difference. To the equivalent performance. The uniformity of the steel requires uniform organization of the material. The steel embryo has the same mechanical properties in any direction, and there is no difference in performance in the longitudinal, transverse and deep directions.
Proper selection of mold materials and high-strength alloy materials can increase mold life. It is recommended that the molds with high life requirements be selected from Sweden's One Victory 8407, DIEVAR, Germany 2344, American H13 (4Gr5MoV1Si), and Japan SKD61 materials. Japan's Hitachi's DAC55, ZHD435 and ASSAB DIEVAR have good toughness and high temperature strength at high hardness, and the die life is also very good.