Vanadium and titanium containing steel for motor train unit axle and heat processing technology thereof

The invention relates to vanadium and titanium containing steel for a motor train unit axle and a heat processing technology thereof. The vanadium and titanium containing steel is prepared from, by weight, 0.24-0.30% of C, 0.20-0.40% of Si, 0.70-1.00% of Mn, 0.90-1.20% of Cr, 0.70-1.30% of Ni, 0.20-0.30% of Mo, 0.10-0.60% of Cu, 0.01-0.04% of Zr, 0.04-0.08% of V, 0.015-0.030% of Ti, 0.001-0.005% of Ca, 0.015-0.045% of Als, the balance Fe and other unavoidable impurities, the weight percentage of P, the weight percentage of S and the weight percentage of T[O] are smaller than or equal to 0.01, 0.008 and 0.0015 respectively. The steel tissue includes tempered sorbite and a small amount of lower bainite, wherein the content of the tempered sorbite on the near surface of the axle is 100%, and the content of the tempered sorbite at the 1/2 radius position of the axle is 80-90%. After heat processing, plasticity and tenacity of the vanadium and titanium containing steel are obviously higher than those of commercial