通过合理设计化学成分、优化控轧控冷及调质工艺,成功开发一种70 mm厚规格Q890高强钢。钢板力学性能良好,其中钢板厚度1/2处及1/4处屈服强度在895~976 MPa之间;抗拉强度在949~1020 MPa之间;伸长率在15.5%~18.0%之间;-20℃及-40℃冲击功分别在165~209 J之间和103~197 J之间。调质处理后的钢板力学性能完全满足GB/T 16270-2009对Q890的要求。回火工艺模拟实验表明,随回火温度的升高,钢板强度下降,但塑性及韧性得到改善;600℃左右回火后,其强度、塑性及韧性达到较好匹配。 Through the rational design of chemical composition, optimization of controlled rolling and cooling, and quenching and tempering, a 70 mm thick Q890 high strength steel has been successfully developed. The mechanical properties of the steel plate are good, among which the plate thickness is 1/2 and 1/4 of the yield strength is between 895 and 976 MPa; the tensile strength is between 949 and 1020 MPa; the elongation is between 15.5% and 18.0% The impact energy at -20 ° C and -40 ° C is between 165 and 209 J and between 103 and 197 J, respectively. After quenched and tempered steel mechanical properties fully meet the GB / T 16270-2009 Q890 requirements. Tempering simulation experiments show that with the tempering temperature, steel strength decreased, but the ductility and ductility improved; 600 ℃ after tempering, the strength, ductility and toughness to achieve a better match.