Heat treatment process of high-carbon chromium-nickel heat- resistant stainless steels

摘要

The present invention relates to a heat treatment process of high- carbon chromium-nickel heat-resistant stainless steels for the purpose of improving the creep rupture strength of the steel at temperatures over about 800° C particularly at about 1000° C. P PThe feature of the present invention lies in that heat- resistant stainless steels containing 0.2 - 1.5% C, 15 - 40% Cr, 10 - 50% Ni, 5% or less Si, 15% or less Mn, with the balance Fe, and impurities are heated for 1 to 60 minutes in a temperature range from 1280° C to 1350. degree. C and then quenched to room temperature at cooling rates higher than 200° C/min. in order to produce the eutectic carbide structure consisted of the matrix metal and carbide phases in which M.sub. 7 C.sub.3 -type carbide is contained not less than 25% by weight of the total weight of the carbides, that are present in the said eutectic carbide structure, at grain boundary triple points, along grain boundaries and within grains.