420 MPa grade high-performance anti-shock H-type steel and preparation method thereof

The invention discloses 420 MPa grade high-performance anti-shock H-type steel and a preparation method thereof. The 420 MPa grade high-performance anti-shock H-type steel comprises, by weight, 0.15-0.18 % of C, 0.03-0.45 % of Si, 1.35-1.55 % of Mn. 0.070-0.090 % of V, not larger than 0.015 % of P, not larger than 0.020 % of S and the balanced E and inevitable impurities. The preparation method comprises the steps of molten steel smelting, deoxygenation alloying, molten steel LF furnace refining, molten steel casting and after-treatment. According to the 420 MPa grade high-performance anti-shock H-type steel and the preparation method thereof, the high V-N micro alloying technology is adopted for smelting, and austenite grains are effectively refined; the nitrogen content is increased in the smelting process, carbonitride of vanadium is formed to be dispersed and distributed in the grain boundary positions, nucleation of the austenite grains is promoted, and the austenite grains are further refined; through the technologies of rolling, cold control, rapid cooling and the like, the excellent appearance and the excellent surface quality of the H-type steel are guaranteed, the machining stress is relieved, and the performance is improved.