本发明公开了一种低压缩比690MPa级特厚钢板及其制造方法,涉及钢铁冶炼技术领域,其化学成分及质量百分比如下:C:0.06%～0.10%,Si:0.20%～0.50%,Mn:1.45%～1.80%,P≤0.015%,S≤0.003%,Ni:1.20%～1.80%,Cu:0.10%～0.40%,Mo:0.10%～0.50%,Nb:0.010%～0.050%,V:0.001%～0.040%,Ti:0.001%～0.020%,Al:0.015%～0.040%,其余为Fe及不可避免的杂质.制得低温韧性优良,强韧性匹配好,120～160mm厚690MPa级特厚超高强钢板.

The invention discloses a low-compression-ratio 690 MPa-grade super-thick steel plate and a manufacturing method thereof, and relates to the technical field of steel smelting. The low-compression-ratio 690 MPa-grade super-thick steel plate comprises the following chemical components in percentage by mass: 0.06-0.10% of C, 0.20-0.50% of Si, 1.45-1.80% of Mn, no more than 0.015% of P, no more than 0.003% of S, 1.20-1.80% of Ni, 0.10-0.40% of Cu, 0.10-0.50% of Mo, 0.010-0.050% of Nb, 0.001-0.040% of V, 0.001-0.020% of Ti, 0.015-0.040% of Al, and the balance of Fe and inevitable impurities. The 690 MPa-grade super-thick steel plate with excellent low-temperature toughness, excellent toughness matching and 120-160 mm thickness is prepared.