本发明公开了一种屈服785MPa级大厚度海洋工程用钢板及生产方法,所述钢板化学成分组成及其质量百分含量为:C:0.07～0.10%,Si:0.20～0.50%,Mn:0.80～1.00%,P≤0.010%,S≤0.005%,Ni:7.00～8.00%,Cr:0.60～0.80%,Mo:0.60～0.80%,V:0.06～0.08%,Al:0.020～0.050%,其余为Fe和不可避免的杂质;所述生产方法包括加热,轧制,热处理工序. 本发明通过合理的化学成分设计及轧制和热处理工艺, 所得钢板屈服强度≥785MPa, 抗拉强度≥870MPa, 60℃纵向冲击功≥70J, 厚度180～200 mm.

The invention discloses a yield strength 785 MPa grade large-thickness marine engineering steel plate and a production method thereof. The steel plate comprises the following chemical components of, in percentage by mass, 0.07%-0.10% of C, 0.20%-0.50% of Si, 0.80%-1.00% of Mn, less than or equal to 0.010% of P, less than or equal to 0.005% of S, 7.00%-8.00% of Ni, 0.60%-0.80% of Cr, 0.60%-0.80% ofMo, 0.06%-0.08% of V, 0.020%-0.050% of Al, and the balance Fe and inevitable impurities. The production method comprises the steps of heating, rolling and heat treatment. According to the steel plateand the method, the design of the chemical components and the processes of rolling and heat treatment are reasonable, the yield strength of the obtained steel plate is greater than or equal to 785 MPa, the tensile strength is greater than or equal to 870 MPa, the longitudinal impact work at minus 60 DEG C is greater than or equal to 70 J, and the thickness is 180-200 mm.