| 摘要 |
<p>Disclosed is a thick steel plate production method wherein: a steel piece having a specified component composition is heated to 1000-1200°C; then, with the plate-thickness centre temperature at 950-1200°C, initial rolling is carried out for 4-16 passes at a cumulative rolling reduction rate of 50-95%; next, with the plate-thickness centre temperature at 850-950°C, latter rolling is carried out for 2-8 passes with each pass being at a rolling reduction rate of 10-25% and pass time being 3-25 seconds; then, accelerated cooling is carried out wherein the plate-thickness centre temperature is cooled from 750°C or above to 650°C or lower at a cooling speed of 1-50°C/s. The thick steel plate produced is characterised by having a plate thickness of 10-40mm and yield stress of 315-550 MPa, having a microstructure which is a mixed structure of ferrite and bainite, or, ferrite, perlite and bainite, and having an average crystal particle diameter of 5-20 µm.</p> |
