本发明公开特宽厚壁低屈强比X80直缝焊管用钢及其生产方法。钢中含有，C：0.045％～0.065％、Si：0.26％～0.40％、Mn：1.60％～1.80％、P≤0.010％、S≤0.0015％、Nb：0.04％～0.06％、Ti：0.008％～0.020％、Ni：0.10％～0.24％、Cu：0.16％～0.25％、Mo≤0.12％、Cr≤0.30％、Ni+Cu+Mo+Cr：0.45％～0.75％、Al：0.010％～0.030％、N：0.0010％～0.0040％，其余为Fe和不可避免的杂质。铸坯加热温度1190～1220℃，均热温度1170～1200℃；粗轧开轧温度1100～1140℃，精轧开轧温度810～840℃，开冷温度710～750℃。成品钢板厚度≥30mm、宽度≥4320mm，低温韧性和抗应变性良好。

The invention discloses extra-wide thick wall low bending strength ratio X80 straight seam welding pipe steel and a production method thereof. In steel, C: 0.045 % ~0.065%, Si: 0.26% ~ 0.40%, Mn: 1.60% ~ 1.80%, P≤ 0.010%, S≤ 0.015%, Nb: 0.04% ~ 0.06%, Ti: 0.08% ~ 0.020%, Ni: 0.10% ~ 0.24%, Cu: 16% ~ 25%, Mo≤ 12%, Cr≤ 30%, Ni+Cu+Mo+Cr: 0.45% ~ 0.75%, Al: 0.010% ~ 0.030%, N: 0.0010% ~ 0.0040%, the rest are Fe and inevitable impurities. Casting billet heating temperature is 1190 ~ 1220℃, soaking temperature is 1170 ~ 1200℃; Rough rolling opening temperature is 1100 ~ 1140℃, finishing rolling opening temperature is 810 ~ 840℃, cooling temperature is 710 ~ 750℃. The thickness of the finished steel plate is more than 30mm, the width is more than 4320mm, the steel plate has good low temperature toughness and good strain resistance.