ZL305铝合金铸件裂纹形成原因分析  

Analysis on the Crack Formation in Aluminum Alloy Casting

作　　者：赵彦森 王鹏云[2] 张海洋[3] 王岳[2] 高灵清[2] ZHAO Yansen;WANG Pengyun;ZHANG Haiyang;WANG Yue;GAO Lingqing(Military Representatives Office of the Navy,Zhengzhou 450015,China;Luoyang Ship Material Research Institute,Luoyang 471023,China;713 Research Institute of China Shipbuilding Industry Corporation,Zhengzhou 450015,China)

机构地区：[1]海装某军事代表室,河南郑州450015 [2]中国船舶重工集团公司第七二五研究所,河南洛阳471023 [3]中国船舶重工集团公司第七一三研究所,河南郑州450015

出　　处：《材料开发与应用》2020年第5期40-44,共5页Development and Application of Materials

摘　　要：ZL305铝合金铸件使用多年后出现局部开裂。为探明原因,采用光学显微镜、扫描电镜、化学分析对开裂部位进行分析,结果表明,铸件开裂部位属应力腐蚀开裂。原因是合金中镁含量超过标准上限,在使用过程中逐步在晶界析出β相并呈链状,降低了晶界抗腐蚀性能,加之长期在海洋环境中承受较大应力,产生应力腐蚀导致开裂。In order to find out the causes for local cracking in ZL305 aluminum alloy casting after many years of service,optical microscope,scanning electron microscope and chemical analysis were used to analyze the cracking position.It is found out that the cracking of the casting belongs to stress corrosion cracking.The reason is that the magnesium content in the alloy exceeds the upper limit of the standard,and β phase precipitates gradually at the grain boundary and takes on chain shape during the service,which reduces the corrosion resistance of the grain boundary.In addition,the alloy bears large stress in the marine environment for a long time,resulting in stress corrosion and cracking.

关 键 词：铸造铝合金 Β相 应力腐蚀 

分 类 号：TG457.1[金属学及工艺—焊接]