-AL, the main function is to refine grain and deoxidation, can promote nitriding layer in nitriding steel, when the content is high, can improve the oxidation resistance at high temperature, resistance to H2S gas corrosion, solid solution strengthening effect, improve the heat strength of heat resistant alloy; ---------B, trace boron can improve the hardenability of steel, but with the increase of carbon content in steel, the improvement of hardenability gradually weakens or even completely disappears; ---------C, with the increase of the content, the hardness and strength of the steel also increase, but the plasticity and toughness decrease; ---------Co, has the effect of solid solution strengthening, so that steel has red hardness, improve high temperature performance, oxidation resistance and corrosion resistance, as an important alloy element of superalloy and superhard high-speed steel, improve the Ms point of steel, reduce the hardenability of steel; ----------Cr, improve the hardenability of steel, and has a secondary hardening effect, increase the wear resistance of high carbon steel, the content of more than 12%, so that the steel has good high temperature oxidation resistance and oxidation resistance medium corrosion effect, improve the thermal strength of steel, is the main alloy element of stainless acid-resistant steel and heat-resistant steel, but the content is high, easy to produce brittleness; ----------Mn, reduce the lower critical point of steel, increase the degree of supercooling during austenite cooling, refine the pearlite structure to improve its mechanical properties, as an important alloying element of low alloy steel, can significantly improve the hardenability of steel, but there is an adverse tendency to increase grain coarsening and temper brittleness; ----------Mo, improve the hardenability of steel, content 0.5%, can reduce the temper brittleness, there is a secondary hardening effect. Increase the thermal strength and creep strength, and improve the corrosion resistance of organic acids and reducing media when the content is 2%--3%; ----------N, there is not obvious solution strengthening and improve the effect of hardenability, improve creep strength, and other elements in steel, precipitation hardening, surface nitridation, improve hardness and wear resistance, increase corrosion resistance, in low carbon steel, residual nitrogen will lead to aging brittleness.
|
