460MPa-grade maritime work steel with excellent fracture resistance and preparation method of 460MPa-grade maritime work steel

The invention discloses 460MPa-grade maritime work steel with excellent fracture resistance and a preparation method of the 460MPa-grade maritime work steel. The 460MPa-grade maritime work steel comprises 0.05%-0.10% of C, 0.15%-0.40% of Si, 1.40%-2.00% of Mn, less than or equal to 0.008% of P, less than or equal to 0.002% of S, 0.15%-0.45% of Cu, 0.50%-1.00% of Ni, 0.15%-0.40% of Cr, 0.015%-0.05% of Nb, 0.007%-0.02% of Ti, 0.015%-0.055% of Alt, less than or equal to 0.001% of O, less than or equal to 0.005% of N and the balance Fe and inevitable impurities, wherein Pcm is less than or equal to 0.24%. According to the invention, the 460MPa-grade marine steel with the maximum thickness of 100mm and excellent fracture resistance is obtained by optimizing the component screening ratio, the preparation process, the toughness matching of the microscopic structure and the like. 本发明公开了一种抗断裂性能优良的460MPa级海工钢及其制备方法，包括：C：0.05％～0.10％，Si：0.15％～0.40％，Mn：1.40％～2.00％，P≤0.008％，S≤0.002％，Cu：0.15％～0.45％，Ni：0.50％～1.00％，Cr：0.15％～0.