1700MPa-grade martensite cold-rolled high-strength steel and production method thereof

The invention discloses 1700MPa-grade martensite cold-rolled high-strength steel and a production method thereof. The cold-rolled high-strength steel comprises the following chemical components: 0.26%-0.33% of C, 0.2%-0.5% of Si, 0.5%-0.8% of Mn, less than or equal to 0.015% of P, less than or equal to 0.005% of S, 0.03%-0.07% of Als, 0.2%-0.4% of Cr, 0.03%-0.05% of Ni, 0.02%-0.04% of Nb, 0.02%-0.05% of Ti, 0.12%-0.17% of Cu, 0.003%-0.007% of Ca, less than or equal to 0.006% of N and the balance of Fe and inevitable impurities. The production method comprises the procedures of smelting, continuous casting, hot rolling, acid rolling and continuous annealing. The cold-rolled high-strength steel provided by the invention has good formability and excellent delayed cracking resistance. 本发明公开一种1700MPa级马氏体冷轧高强钢及其生产方法，冷轧高强钢的化学成分组成为：C：0.26%～0.33%，Si：0.2%～0.5%，Mn：0.5%～0.8%，P≤0.015%，S≤0.005%，Als：0.03%～0.07%，Cr：0.2%～0.4%，Ni：0.03～0.05%，Nb：0.02%～0.04%，Ti：0.02%～0.05%，Cu：0.12%～0.17%，Ca为0.003%～0.007%，N≤0.006%，其余为Fe及不可避免杂质；其生产