A7N01铝合金焊接接头的不均匀特性  

Inhomogeneity for A7N01 aluminum alloy welded joint

作　　者：张亮[1] 方洪渊[1] 王林森[1,2] 刘雪松[1] 

机构地区：[1]哈尔滨工业大学先进焊接与连接国家重点试验室,哈尔滨150001 [2]中国东方电气集团东方锅炉股份有限公司,自贡643001

出　　处：《焊接学报》2012年第11期97-100,118,共4页Transactions of The China Welding Institution

摘　　要：以A7N01铝合金焊接接头为分析对象,通过金相试验、显微硬度试验、拉伸试验和缺口疲劳试验分析了焊接接头微区的不均匀性.结果表明,A7N01铝合金焊接接头母材、焊缝、热影响区内的组织和硬度差别较大,焊缝硬度最低约为HV75,母材焊缝最高约为HV110,热影响区内硬度变化较大.母材的屈服强度和抗拉强度高于焊缝和热影响区.而热影响区的断后伸长率最高.三个区域内疲劳裂纹萌生寿命差异较小,裂纹萌生寿命与总寿命之比近似为常数,疲劳总寿命差别明显,母材的疲劳总寿命最长,焊缝疲劳总寿命最短.Inhomogeneity for A7N01 alloy welded joint was investigated in terms of microstructure,microhardness,tensile properties and fatigue life.Experiment results show that microstructure and microhardness of base metal,weld metal and HAZ are much different.Microhardness for weld metal is about HV75 which is the lowest compared with HV110 for base metal and HAZ in which microhardness changes significantly.The ultimate tensile strength and yield strength of base metal is higher than that of weld metal and HAZ.Notched specimens were used in fatigue test to study the inhomogeneity of the joint.Experiment results demonstrate that there is less difference in fatigue crack initiation life for the three micro-zones,and the ratio of fatigue initiation life to the total faitgue life is contant for each micro-zone.However,the difference of fatigue life is remarkable that weld metal has the shortest total fatigue life and base metal has the longest one.

关 键 词：铝合金 不均匀性 疲劳裂纹萌生寿命 微区性能 

分 类 号：TG405[金属学及工艺—焊接]