轧制复合Q235B特厚钢板组织和力学性能的研究

Research on Microstructure and Mechanical Properties of Rolling Cladding Q235B Extra Thick Steel Plate

特厚板Q235B在真空组坯焊接后进行了多道次轧制复合,厚度从400mm轧制到80mn。结果表明:轧制复合钢板没有明显缺陷,超声波探伤、力学性能满足要求。轧制后的晶粒组织为均匀细小的铁素体+珠光体。拉伸断口宏观上比较平齐,缩颈不明显;从微观上看,断口存在一部分解理断裂,其余大部分是韧窝,韧窝底为夹杂物,能谱分析为氧化物+MnS。

The multi-pass rolling cladding of Q235 extra-thick steel plate after the vacuum welding was carried out, and rolling thickness was from 400 mm to 80 ram. The results show that rolling cladding plate has no obvious defects, and ultrasonic flaw detection and mechanical properties meet the requirements. The grain microstructure after rolling is uniform and fine ferrite＋pearlite. In macrography, the tensile fracture surface is relatively flat, and the shrinkage is not obvious. From the microscopic view, there is some cleavage fracture and most of the rest is the dimple. And there are inclusion in ductile pit bottom, which are oxide ＋MnS after energy spectrum analysis.