采用手工电弧焊分别对三种厚度WDB620钢板对接接头进行焊接,并对焊接接头的金相组织和力学性能进行了试验研究。结果表明,三种板厚下WDB620钢的焊接接头都具有较高的抗拉强度和低温冲击韧性,焊接接头的塑性、抗裂性都较好,在所选用焊接工艺参数下焊接接头具有优良的综合力学性能。不管是常温或是-20℃条件下,热影响区的冲击韧性都优于焊缝区。热影响区和焊缝区的金相组织基本为粒状贝氏体+少量铁素体,且热影响区晶粒较细,焊缝区晶粒较粗,导致晶粒细小的热影响区冲击韧性优于晶粒粗大的焊缝区。 The WDB620 steel plate butt joints were welded by hand arc welding, and the microstructure and mechanical properties of the welded joints were tested. The results show that the welded joint of WDB620 steel has higher tensile strength and low temperature impact toughness under all three thicknesses. The plasticity and crack resistance of the welded joint are good. The welded joint has excellent Comprehensive mechanical properties. The impact toughness of the heat-affected zone is better than the weld zone at room temperature or -20 ℃. The microstructure of the HAZ and the weld zone is basically granular bainite + a small amount of ferrite, and the heat affected zone has fine grains and coarser grains in the weld zone, resulting in the small heat affected zone impact toughness Better than coarse grain weld zone.