Chemical elements of steel shot

　　In the production of steel shot, the chemical composition is a basic indicator of product production, which affects the microstructure and heat treatment effect of the product. Therefore, in order to achieve the effect of alloy steel shot, it is necessary to understand its chemical composition. .

　　According to relevant standards, the chemical composition of alloy steel shot is: carbon (C) content: 0.85-1.20%; silicon (Si) content: ≥ 0.40; manganese (Mn) content: 0.35-1.20%; sulfur (S) content: ≤0.05%; Phosphorus (P) content: ≤0.05%.

　　1. The content of silicon in the range of 0.4% has the following advantages, reducing the melting point, improving the fluidity, and deoxidizing the molten steel; solid solution strengthening improves the strength of the steel and improves the hot tendency of the steel, but when the content is too high, It will cause the reduction of section shrinkage, especially the impact toughness will be significantly reduced, and the brittleness of the alloy steel shot will increase, which is easy to break. Therefore, the silicon content should be controlled between 0.6% and 1.5%.

　　2. Manganese can form an infinite solid solution with iron, resulting in solid solution strengthening and improving the strength and hardness of the steel; on the other hand, it can increase the fluidity, reduce the crystallization temperature range, and play the role of composite deoxidation of molten steel together with silicon. Manganese can improve the deoxidation effect of silicon and aluminum, and can also form sulfides with sulfur to remove the harmful effects of sulfur. 3. Sulfur is also a harmful element. Sulfur is only soluble in molten steel, and its solubility in solid solution is very small. Severe sulfur segregation occurs during solidification, resulting in hot brittleness of steel. 4. Phosphorus is a harmful element. Although it has a strong solid solution strengthening effect and can improve the strength and hardness of steel, phosphide can strongly reduce the toughness of steel, increase low temperature brittleness, and increase the breaking rate of steel shot. It should be strictly control. 5. Tungsten is a carbide forming element, which improves the hardness and wear resistance of the material and improves the stability of austenite. In the understanding of the chemical composition of steel shot, the hardness and strength of the product are presented by the above chemical elements. When adding chemical elements, it must be carried out in accordance with its standards, and its content must be strictly controlled to avoid harmful elements. Too much will reduce the quality of alloy steel shot.