Zhang Chen, Li Geng, Gao Ming, Zeng XiaoYan
School of Mechanical & Electrical Engineering, Wuhan Institute of Technology, Wuhan 430073, China.
Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, Wuhan 430074, China.
Materials (Basel). 2017 Jan 26;10(2):106. doi: 10.3390/ma10020106.
Both laser-arc hybrid welding and narrow gap welding have potential for the fabrication of thick sections, but their combination has been seldom studied. In this research, 40 mm thick mild steel was welded by narrow gap laser-arc hybrid welding. A weld with smooth layer transition, free of visible defects, was obtained by nine passes at a 6 mm width narrow gap. The lower part of the weld has the lowest mechanical properties because of the lowest amount of acicular ferrite, but its ultimate tensile strength and impact absorbing energy is still 49% and 60% higher than those of base metal, respectively. The microhardness deviation of all filler layers along weld thickness direction is no more than 15 HV, indicating that no temper softening appeared during multiple heat cycles. The results provide an alternative technique for improving the efficiency and quality of welding thick sections.
激光电弧复合焊和窄间隙焊在厚板焊接方面都具有潜力，但二者的结合却鲜有研究。在本研究中，采用窄间隙激光电弧复合焊对40毫米厚的低碳钢进行焊接。在6毫米宽的窄间隙下经过九道焊获得了层间过渡平滑、无可见缺陷的焊缝。焊缝下部由于针状铁素体含量最低，其力学性能最差，但其抗拉强度和冲击吸收能量仍分别比母材高49%和60%。沿焊缝厚度方向所有填充层的显微硬度偏差不超过15 HV，表明在多次热循环过程中未出现回火软化现象。研究结果为提高厚板焊接效率和质量提供了一种替代技术。
