Patent ID: 10801090

Abstract:
The invention discloses an ultra-high obdurability steel plate having a low yield ratio, comprising the chemical elements in mass percentages of: C: 0.18-0.34%, Si: 0.10-0.40%, Mn: 0.50-1.40%, Cr: 0.20-0.70%, Mo: 0.30-0.90%, Nb: 0-0.06%, Ni: 0.50-2.40%, V: 0-0.06%, Ti: 0.002-0.04%, Al: 0.01-0.08%, B: 0.0006-0.0020%, N≤0.0060%, O≤0.0040%, Ca: 0-0.0045%, and the balance of Fe and other unavoidable impurities. The invention also discloses a process of manufacturing the steel plate, wherein the heating temperature is 1080-1250° C.; the quenching temperature is 860-940° C.; and the tempering temperature is 150-350° C.