利用IPG YLS-6000型光纤激光器和摆动焊接头对Q235钢进行了线性焊接和摆动焊接试验,对比分析了两种焊接接头的显微组织及力学性能。结果表明:激光束摆动焊接较线性焊接可显著增加焊缝宽度(1.34 mm→1.60 mm);两种焊接接头各微区的显微组织相同,焊缝组织为板条马氏体、板条贝氏体和晶界铁素体,热影响区的完全奥氏体化区主要为铁素体和板条马氏体,不完全奥氏体化区则为晶粒尺寸不均匀的铁素体和珠光体;摆动焊接接头的整体硬度高于母材,焊缝纵向抗拉强度约为母材的1.74倍,延伸率仅为母材的66.7%,冲击韧度可达母材的90%左右,与线性焊接接头具有相同的力学性能。摆动焊接可以有效降低激光焊接对组对间隙的要求,且对焊接接头的硬度、强度和韧性无不利影响。

In this study, Q235 steel was welded by linear welding and oscillating welding using an IPG YLS-6000 fiber laser and oscillating welding head. The microstructures and mechanical properties of the two welded joints were compared and analyzed. Results show that laser beam oscillating welding can significantly increase the weld width from 1.34 mm to 1.60 mm when compared with linear welding; the microstructures of the two welded joints are lath martensite, lath bainite, and grain boundary ferrite; the complete austenitizing zones in heat-affected zones are made of ferrite and lath martensite, and the incomplete austenitizing zones consist of ferrite and pearlite with uneven grain sizes. The overall hardness of the oscillating welded joint is higher than that of the base metal. In addition, the tensile strength of the oscillating welded joint is 1.74 times that of the base metal, while the ductility and impact toughness of the joint are 66.7% and 90% that of the base metal, respectively. The oscillating welded joint has the same mechanical properties as the linear welded joint. Oscillating welding can effectively reduce the gap requirement associated with laser welding and has no adverse effects on the hardness, strength, and toughness of the welded joint.