Medium carbon ultra-high strength steel with alloy element containing S between 5% and 10%. It is developed on the basis of hot-working die steel. The main alloy elements are Cr, Mo, W, V, Si, etc. The hardenabilhy is very high. Generally, it can obtain complete martensite structure by air quenching. After high temperature tempering at 500-600 ° C, dispersed M2C and MC type carbide precipitate to produce secondary hardening effect. The tensile strength at room temperature can reach over 1500MPa and still maintain high strength at temperatures ranging from 300 to 500 ℃, making it suitable for use at medium temperatures. The yield strength can reach more than 2500MPa with proper plasticity when the austenite deformation heat treatment process is adopted.
No classification at present.