The influence of alloying elements on the phase transition during heating
Alloying elements affect the rate of austenite formation and the size of austenite grains during heating. (1) Influence on the formation rate of austenite: Cr, Mo, W, V and other strong carbide forming elements have a high affinity for carbon, forming alloy carbides that are insoluble in austenite, which significantly slows down austenite Formation rate: Co, Ni and other non-carbide-forming elements increase the diffusion rate of carbon and accelerate the formation of austenite; alloy elements such as Al, Si, Mn have little effect on the formation rate of austenite. (2) Effect on austenite grain size: most alloying elements have the effect of preventing austenite grain growth, but the degree of influence is different. The elements that strongly hinder the growth of grains are: V, Ti, Nb, Zr, etc.; the elements that hinder the growth of grains are: W, Mn, Cr, etc.; the elements that have little effect on the growth of grains are: Si, Ni, Cu, etc.; elements that promote grain growth: Mn, P, etc.