EH40船板钢的弯曲焊丝窄间隙MAG焊工艺研究

Research on Narrow Gap Metal Active Gas Arc Welding with Curved Wire for EH40 Ship Steel Plate

采用弯曲焊丝窄间隙熔化极活性气体保护焊接(MAG)法对EH40船用高强钢进行了平焊位置的焊接试验。焊接试验过程中,焊接热输入为13 k J/cm,采用了3种焊接工艺参数。检测了焊接接头的组织和力学性能。试验结果表明,焊缝质量良好,无侧壁未熔合及其他焊接缺陷。此外,焊接接头的热影响区比较窄,其组织主要为贝氏体和铁素体,平均冲击吸收能量为267J,与母材基本相同。焊接接头的强度高于母材。焊接接头的力学性能满足船级社要求。

Trial welding in flat position of marine high-strength EH40 steel plate was done by narrow gap metal active gas arc welding with a curved wire. The welding heat input was as large as 13 k J/cm, and three types of welding process parameters were employed in the trial-welding.Microstructure and mechanical properties of the welded joint were tested. The results showed that the weld offered good welding quality,and failure of the sidewall to be fused and other welding defects were not found in it. Moreover,the heat affected zone of welded joint was more narrow,and exhibited microstructure composed predominantly of bainite and ferrite,and mean impact absorption energy of 267 J which is nearly equivalent to that of the base metal. The weld joint was superior to the base metal in strength. The mechanical properties of the welded joint met the requirements of classification society.