Abstract: The 250 mm casting slab of steel Q355D bearing 0. 14% ~ 0. 18% C and 1.40% ~ 1.60% Mn is hot-rolled by the controlled rolling process. The results show that the microstructure of rolled plate is fine and uniform by rough rolling at 1050 - 1130℃  , finishing rolling at 920℃ and final rolling at 880 ℃ , and the final cooling below 670℃  , the properties of the 70 mm and 80 mm thick plate can meet the requirements of Q355D steel grade and the Z25 reduction of area (RA) is 58% 〜64% to meet the requirement of Z25 direction RA≥25%.

摘要： 采用控制轧制工艺对0.14%～0.18%C,1.40%～1.60%Mn Q355D钢250 mm连铸板坯进行热轧,结果表明,在粗轧温度1050～1130℃、精轧温度920℃、终轧温度880℃控制轧制条件下,终冷温度在670℃以下生产的厚板组织细小均匀,生产70mm和80mm规格厚板性能符合Q355D级别要求,并且Z25断面收缩率(RA)为58%～64%满足Z25方向RA≥25%的要求。

关键词: 低合金钢Q355D, 厚板, 控轧控冷, 力学性能, 组织