一种高韧性高速车轴用钢,所述钢的化学成分以重量百分比计为,C：0.20～0.28％,Si：0.15～0.40％,Cr：0.90～2.00％,Mn：0.15～0.80％,V：0.15～0.30％,Nb：0.00～0.06％,Ni：0.90～1.50％,Mo：0.15％～0.30％,Alt：0.010～0.030％,P：<0.010％,S：<0.010％,O：<0.0015％,N：<0.008％,余为Fe和不可避免的杂质；同时本发明还提供一种钢的热处理方法。本发明采用新型中低C、高V、微Nb、Mo复合微合金化、较高Cr、Ni合金设计,经两次淬火+高温回火热处理后,可以获得细晶奥氏体晶粒及高V微合金纳米第二相增强的马氏体组织,实现高强度和高韧性的优异匹配,最终使高速车轴具有良好的抗冲击和抗疲劳等服役性能。

The utility model relates to a high toughness high speed axle steel, and the chemical composition of the steel in weight percentage is C: 0.20 ~ 0.28%,Si: 0.15 ~ 0.40%,Cr: 0.90 ~ 2.00%,Mn: 0.15 ~ 0.80%,V: 0.15 ~ 0.30%,Nb: 0.00 ~ 0.06%,Ni: 0.90 ~ 1.50%,Mo: 0.15% ~ 0.30%,Alt: 0.010 ~ 0.030%,P: < 0.010%,S: < 0.010%,O: < 0.0015%,N: < 0.008%, the rest is Fe and inevitable impurities; The invention also provides a heat treatment method for steel. This invention adopts novel high low C, V, Nb, Mo composite micro alloying, high Cr, Ni alloy design, after two times of high temperature quenching and tempering heat treatment, can get fine grain austenite grain and high V microalloy nano second phase enhanced martensite structure, realize the excellent matching of high strength and high toughness and eventually make the axle has good resistance to impact and fatigue resistance, etc Service performance.