Chromium: chromium can form chromium carbides in the steel, can improve the high temperature strength and wear resistance of the steel, the C curve shifts to the right, to improve the hardenability and tempering stability of hot work die steel H13. Chromium and other carbide forming elements give steel has high hardenability and resistance to softening ability, so H13 steel can be hardened in condition of air cooling. In the 6barN2 gas vacuum processing conditions can harden diameter is 160mm. But add chromium, carbides will increase the inhomogeneity, the steel will appear in the metastable eutectic carbide. Chromium content increased to improve thermal strength of the material, but the toughness of adverse.
Mo: can improve the high temperature hardness and the hardenability of the steel. In addition, molybdenum can hinder the austenite grain growth, thereby to refine the crystal grain, reduce the temper brittleness.
Vanadium: Vanadium to form carbides is easier than the chromium and molybdenum, dissolved in solid solution of iron is extremely small. Vanadium carbides so that the steel has good hot hardness, and refine the grain, improve the wear resistance of hot work die steel H13.
Si: Silicon has strengthening effect is very good for ferritic solid solution replacement, second only to the phosphorus, but also to some extent reduce the steel toughness and plastic. The general will be restricted in the range of steel deoxidation need. If the Si as alloy elements added to steel, the amount is generally not less than 0.4%. Silicon can also improve the tempering resistance. Si can reduce the diffusion rate of carbon in ferrite, the precipitation of carbides is not easy to aggregation when tempering, the increase of tempering stability. In addition, silicon is easy to make the steel presents zonal organization, makes the lateral performance of the steel than the longitudinal performance is poor, also increased the brittle transition temperature of steel. Si also increased decarburization sensitivity of steel, but the Si is beneficial to improve the high temperature oxidation resistance of the mold steel H13 steel.
Mn: Manganese can change the nature and shape of oxide when during solidification of hot work die steel H13. At the same time it has a greater affinity with S, can prevent formation of low melting point sulfides "FeS" at the grain boundaries, and formation of a certain plastic MnS, thereby eliminating the harmful effects of sulfur, improve hot workability of the steel. Mn has a solid solution strengthening effect, thereby enhancing the ferrite and austenite strength and hardness. Although the solid solution strengthening effect is lower than carbon, silicon and phosphorus, but the ductility of the steel is almost not affected. In the "ferrite - pearlite" type steels, only Mn can increase the yield strength and the cold-brittle transition temperature changes to a minimum.
The above article from Songshunsteel official website (http://www.songshunsteel.com/)
The original address: http://www.songshunsteel.com/news_show_27_22_42.html, reproduced please specify
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