焊前热处理对压铸镁合金GTAW焊气孔的影响  

Influences of Heat Treatment Before Welding on Porosity in GTAW Welding of Die Casting Magnesium Alloy

作　　者：李阳[1,2] 游国强[1,3] 马小黎[1] 赵旭[1] 杜娟[1] 陈磊[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400044 [2]国家镁合金材料工程技术研究中心,重庆400044 [3]东风小康汽车有限公司,重庆400030

出　　处：《材料工程》2015年第12期39-44,共6页Journal of Materials Engineering

基　　金：国家自然科学青年基金资助项目(51105393);山东省自主创新专项资助项目(2012CX60301);四川省科技计划资助项目(2013GZ0128)

摘　　要：在不同温度下对压铸AM60B母材进行焊前热处理,待冷至室温后对其实施不填丝GTAW重熔焊接。焊后用扫描电镜对焊缝截面的气孔分布及形貌进行观察,并用粒径分析软件Nano measurer 1.2测量焊缝中气孔尺寸,用基于Matlab二次开发的图像分析程序识别和计算焊缝气孔率。结果表明:焊缝气孔主要分布在焊缝熔融区及熔合线附近;与未经焊前热处理母材对应的焊缝相比,经焊前热处理后所得焊缝中的气孔率及气孔尺寸均降低;随着焊前热处理温度升高,焊后气孔率及气孔尺寸均逐渐增加。The base metals of die casting AM60 Bmagnesium alloy were welded by GTAW without filling material after heat treatment at different temperatures and cooling to room temperature.The distribution and morphology of pores in the sections of welds were observed by scanning electron microscopy,the sizes of the pores in the welds were measured by the particle size analysis software of Nano measurer 1.2,and the weld porosity was distinguished and calculated by a secondary developed image analysis program based on Matlab.The results indicate that：the pores are mainly distributed in the fusion zone and near the fusion line.Compared with the weld without heat treatment before welding,both the porosity and the sizes of pores in the welds with heat treatment before welding decrease.With the increase of the heat treatment temperatures before welding,both the porosity and the sizes of pores after welding increase.

关 键 词：焊前热处理 GTAW 压铸镁合金 气孔 

分 类 号：TG456.7[金属学及工艺—焊接]