2022-11-08
The important role of various alloying elements in steel (2)
03.Molybdenum element
Molybdenum (Mo) in steel can improve hardenability and heat strength, prevent temper brittleness, increase remanence and coercive force and corrosion resistance in some media. In quenched and tempered steel, molybdenum can make parts with larger cross-sections hardened and hardened, improve the tempering resistance or tempering stability of steel, so that parts can be tempered at higher temperatures, thereby more effectively eliminating ( Or reduce) residual stress, improve plasticity. In carburized steel, molybdenum, in addition to the above-mentioned effects, can also reduce the tendency of carbides to form a continuous network on the grain boundary in the carburized layer, reduce the residual austenite in the carburized layer, and relatively increase the surface layer. wear resistance. In forging dies, molybdenum can also maintain a relatively stable hardness of steel and increase resistance to deformation, cracking and wear. In stainless acid-resistant steel, molybdenum can further improve the corrosion resistance to organic acids (such as formic acid, acetic acid, oxalic acid, etc.), hydrogen peroxide, sulfuric acid, sulfurous acid, sulfate, acid dyes, bleaching powder, etc. Especially due to the addition of molybdenum, the pitting corrosion tendency caused by the presence of chloride ions is prevented. W12Cr4V4Mo high-speed steel containing about 1% molybdenum has wear resistance, tempering hardness and red hardness.