本发明属于冶金技术领域，具体地，本发明涉及一种屈服强度460MPa级热轧高韧性耐低温H型钢及其制备方法。本发明的屈服强度460MPa级高韧性耐低温H型钢，其化学成分组成按重量百分比为：C：0.03％～0.07％，Si≤0.3％，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%，O≤0.010%，其余为Fe和不可避免杂质。本发明的采用含N复合微合金化成分设计，从而在普通热轧H型钢轧机上实现460MPa级别以上强度的同时，获得较高的强韧性。本发明的H型钢产品其力学性能良好，屈服强度≥460MPa，抗拉强度≥600MPa，延伸率≥18%；-40℃纵向冲击功≥100J，适合极低温条件地区使用。

The invention belongs to the technical field of metallurgy, and specifically relates to hot-rolled high-toughness low-temperature-resistant H-shaped steel with the yield strength of 460 MPa and a preparation method thereof. The high-toughness low-temperature-resistant H-shaped steel with the yield strength of 460 MPa comprise, by weight, 0.03-0.07% of C, less than or equal to 0.3% of Si, 1.20%-1.40% of Mn, 0.015%-0.030% of Nb, 0.10%-0.15% of V, 0.015%-0.025% of Ti, 0.25%-0.45% of Ni, 0.30%-0.50% of Cr, 0.01-0.06% of Als, 0.010%-0.023% of N, less than or equal to 0.015% of P, less than or equal to 0.010% of S, less than or equal to 0.004% of O, and the balance Fe and inevitable impurities. According to the hot-rolled high-toughness low-temperature-resistant H-shaped steel, N-containing composite micro-alloying component design is adopted, so that higher strength and toughness can be obtained while the strength above 460 MPa is achieved on a common hot-rolled H-shaped steel rolling machine. The H-shaped steel products is good in mechanical property, the yield strength is larger than or equal to 460 MPa, the tensile strength is larger than or equal to 600 MPa, and the elongation percentage is larger than or equal to 18%; and the longitudinal impact power at the temperature of 40 DEG,C is larger than or equal to 100J; and the hot-rolled high-toughness low-temperature-resistant H-shaped steel is suitable for being used in regions with extremely low temperature.