PRODUCTION OF WEAR-RESISTANT STEEL PLATE HAVING EXCELLENT RESISTANCE TO DELAYED CRACKING

摘要

PURPOSE:To obtain a titled wear-resistant steel plate having high hardness by subjecting a steel contg. C, Si, Mn, Cr, Mo, Sol.Al and B respectively at prescribed ratios as principal components to hot rolling in a specific temp. range then subjecting the same to a hardening treatment from the temp. at the A3 transformation point or above. CONSTITUTION:A steel contg. 0.15-0.45% C, 0.05-1.00% Si, 0.05-0.45% Mn, 0.05-1.00% Cr, 0.03-0.85% Mo, 0.010-0.150% Sol.Al and 0.0003-0.0025% B, contg. =1 kind among Cu, Ni, V, etc. respectively at prescribed ratios according to need and consisting of the balance Fe with inevitable impurities is prepd. The content of N, P, S, Pb and Sb in said impurities is regulated as well. Such steel is hot-rolled at 1,000-1,200 deg.C to prevent formation of coarse crystal grains. Such steel is then subjected to hardening from the temp. at the As3 transformation point or above by which the intended wear resistant steel plate having excellent resistance to delayed cracking is obtd.