A novel Al−Mg−Er−Zr alloy was welded by highly efficient tandem GMAW,and the effect of Er on the porosity,microstructure and mechanical properties of the weld joints were investigated by comparing them with Al5083 all...A novel Al−Mg−Er−Zr alloy was welded by highly efficient tandem GMAW,and the effect of Er on the porosity,microstructure and mechanical properties of the weld joints were investigated by comparing them with Al5083 alloy weld joints.The results showed that compared to the welds without Er addition,the porosity decreased from 0.78%to 0.38%,which was attributed to the ability of Er to reduce the content of free hydrogen in the welds.Furthermore,the grain size near the fusion boundary and weld metal(WM)was significantly refined with the addition of Er.Grain refinement near the fusion boundary was attributed to the heterogeneous nucleation induced by Al_(3)(Er,Zr)from base metal,while grain refinement in WM was caused by the hindering effect of Al_(3)Er on grain boundary migration.Additionally,the ultimate tensile strength of the weld joints increased from 272.44 to 338.74 MPa with Er addition.The precipitation strengthening induced by Al_(3)Er contributed to an increase by 20%in strength.展开更多
在熔化极气体保护焊(Gas metal arc welding,GMAW)过程中,当焊接速度超过临界值后,焊缝成形变差,出现咬边和驼峰焊道,无法满足生产要求。研究证明,熔池中动量很大的后向液体流是产生驼峰焊道的主要原因。自主研发外加磁场发生装置,向熔...在熔化极气体保护焊(Gas metal arc welding,GMAW)过程中,当焊接速度超过临界值后,焊缝成形变差,出现咬边和驼峰焊道,无法满足生产要求。研究证明,熔池中动量很大的后向液体流是产生驼峰焊道的主要原因。自主研发外加磁场发生装置,向熔池施加横向电磁力,对后向液体流进行主动干预,并调控熔池流态,从而抑制驼峰焊道的形成。在Q235低碳钢板上开展焊接工艺试验,获得了不同磁感应强度下的焊缝表面成形;采用高速摄像技术,拍摄焊接过程中的电弧和熔池图像,分析外加磁场对电弧形态、熔池流场和焊缝成形的影响规律,初步揭示外加磁场抑制驼峰焊道的机理。试验结果表明,外加横向磁场能明显调控熔池流态,减小后向液体流的动量,并能有效抑制驼峰焊道和咬边等缺陷,显著改善焊缝成形,提高临界焊接速度。展开更多
基金the National Key R&D Program of China(No.2023YFB3407800)the National Natural Science Foundation of China(No.U2141213)the experimental supports by Instrumental Analysis Center of Shanghai Jiao Tong University,China.
文摘A novel Al−Mg−Er−Zr alloy was welded by highly efficient tandem GMAW,and the effect of Er on the porosity,microstructure and mechanical properties of the weld joints were investigated by comparing them with Al5083 alloy weld joints.The results showed that compared to the welds without Er addition,the porosity decreased from 0.78%to 0.38%,which was attributed to the ability of Er to reduce the content of free hydrogen in the welds.Furthermore,the grain size near the fusion boundary and weld metal(WM)was significantly refined with the addition of Er.Grain refinement near the fusion boundary was attributed to the heterogeneous nucleation induced by Al_(3)(Er,Zr)from base metal,while grain refinement in WM was caused by the hindering effect of Al_(3)Er on grain boundary migration.Additionally,the ultimate tensile strength of the weld joints increased from 272.44 to 338.74 MPa with Er addition.The precipitation strengthening induced by Al_(3)Er contributed to an increase by 20%in strength.
文摘在熔化极气体保护焊(Gas metal arc welding,GMAW)过程中,当焊接速度超过临界值后,焊缝成形变差,出现咬边和驼峰焊道,无法满足生产要求。研究证明,熔池中动量很大的后向液体流是产生驼峰焊道的主要原因。自主研发外加磁场发生装置,向熔池施加横向电磁力,对后向液体流进行主动干预,并调控熔池流态,从而抑制驼峰焊道的形成。在Q235低碳钢板上开展焊接工艺试验,获得了不同磁感应强度下的焊缝表面成形;采用高速摄像技术,拍摄焊接过程中的电弧和熔池图像,分析外加磁场对电弧形态、熔池流场和焊缝成形的影响规律,初步揭示外加磁场抑制驼峰焊道的机理。试验结果表明,外加横向磁场能明显调控熔池流态,减小后向液体流的动量,并能有效抑制驼峰焊道和咬边等缺陷,显著改善焊缝成形,提高临界焊接速度。
