High-temperature-resistance medium-low-carbon medium-low-alloy steel and preparing method thereof

The invention discloses high-temperature-resistance medium-low-carbon medium-low-alloy steel. The high-temperature-resistance medium-low-carbon medium-low-alloy steel is characterized by comprising chemical components including, by weight percent, 0.20 to 0.30% of C, 2.2 to 3.2% of Cr, 1.5 to 2.5% of Mo, 0.5 to 1.5% of Ni, 0.6 to 0.9% of W, 0.2 to 0.9% of V, 0.1 to 0.15% of Nb, and the balance Fe.The prepared alloy steel has the excellent room temperature toughness and low-temperature impact toughness at the same time, meanwhile, the room temperature strength can be up to above 1210 MPa, at the temperature of 700 DEG C, the high-temperature strength can be above 550 MPa, and the high-temperature strength can be improved by two to four times compared with existing alloy steel. 一种耐高温中低碳中低合金钢，其特征在于：所述中低碳中低合金钢的化学成分按重量百分比计为C：0.20~0.30%、Cr：2.2~3.2%、Mo：1.5~2.5%、Ni：0.5~1.5%、W：0.6~0.9%、V：0.2~0.9%、Nb：0.1~0.15%，其余成分为Fe。本发明制备的合金钢同时具有优异的室温韧性和低温冲击韧性的同时，室温强度达到1210MPa以上，在700℃是高温强度达到550MPa以上，高温强度较现有合金钢提高2-4倍。