High-manganese austenitic steel for ultralow-temperature valve and casting preparation method thereof

The invention discloses high-manganese austenitic steel for an ultralow-temperature valve and a casting preparation method of the high-manganese austenitic steel, the high-manganese austenitic steel comprises, by weight, 0.35%-0.55% of C, 0%-0.5% of Si, 22.5%-25.5% of Mn, 0%-0.015% of P, 0%-0.005% of S, 3.0%-4.0% of Cr, 0%-0.4% of Ni, 0%-0.12% of Mo, 0.05%-0.15% of V, 0.3%-0.7% of Cu, 0%-0.02% of Nb, 0%-0.03% of Ti, 0%-0.005% of B, 0%-0.005% of N and the balance Fe and a small amount of impurities, the high-manganese austenitic steel is formed through casting of a sand box model, and the high-manganese austenitic steel 本发明公开了一种超低温阀门用高锰奥氏体钢及其铸件制备方法，高锰奥氏体钢包含以下重量百分比的成分，C:0.35~0.55%、Si:0~0.5%、Mn:22.5~25.5%、P:0~0.015%、S:0~0.005%、Cr:3.0~4.0%、Ni:0~0.4%、Mo:0~0.12%、V:0.05~0.15%、Cu:0.3~0.7%、Nb:0~0.02%、Ti:0~0.03%、B:0~0.005%、N:0~0.005%、余量为Fe和少量杂质，并通过砂箱模型浇注成型，本发明所制高锰奥氏体钢具有较高抗拉强度、屈服强度、超低温冲击韧性。