YIELD STRENGTH 460 MPA GRADE HOT-ROLLED HIGH-TOUGHNESS LOW-TEMPERATURE-RESISTANT H-BEAM AND PREPARATION METHOD THEREFOR

摘要

A yield strength 460 MPa grade hot-rolled high-toughness low-temperatureresistant H-beam, the weight percentage of the chemical components thereof being: C: 0.03%-0.07% Si≤3%, Mn: 1.20%-1.40%, Nb: 0.015%-0.030%, V: 0.10%-0.15%, Ti: 0.015%-0.025%, Ni: 0.25%-0.45%, Cr: 0.30%-0.50%, Als: 0.01%-0.06%, N: 0.010%-0.023%, P≤0.015%, S≤0.010%, and 0<0.004%, and the remainder being Fe and inevitable impurities. By using the N-containing composite micro-alloying composition design, higher strength and toughness can be obtained whilst achieving strength of 460MPa grade and above on an ordinary hot-rolling H-beam steel-rolling machine; the H-beam product has good mechanical properties, yield strength≥460 MPa, tensile strength≥600mpa, and elongation ≥18% and -40°C longitudinal impact energy ≥100J, being suitable for use in extremely low temperature conditions.