电子探针测试胀裂失效不锈钢换热器管中的氮元素  

EPMA Test of Nitrogen in Stainless Steel Heat Exchanger Tube with Expansion Crack Failure

作　　者：赵同新 王宜权 崔会杰 孙友宝 黄涛宏 ZHAO Tongxin;WANG Yiquan;CUI Huijie;SUN Youbao;HUANG Taohong(Analytical Applications Center of SHIMADZU(China)Co.,Ltd.,Shanghai 200233,China)

机构地区：[1]岛津企业管理(中国)有限公司分析中心,上海200233

出　　处：《理化检验（物理分册）》2021年第6期45-47,65,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：某2205双相不锈钢换热器管在胀管连接工艺中出现了裂纹,使用电子探针(EPMA)分析了该换热器管的失效原因。结果表明:局部的强奥氏体形成化元素氮的富集导致此处出现了异常的组织分布,原本两相组织含量相近的位置形成了粗大的奥氏体单相区,其塑性和强度均比正常组织差。在加工过程中微裂纹萌生,最终导致换热器管发生胀裂。Cracks appeared in the expansion process of a 2205 duplex stainless steel heat exchanger tube. The failure causes of the heat exchanger tube were analyzed by electron probe micro analyzer(EPMA). The results show that the enrichment of local strong austenite forming element nitrogen led to abnormal microstructure distribution here. The single-phase zone of coarse austenite was formed at the position where the content of two-phase should be similar, and its plasticity and strength were worse than the normal microstructure. In the process of machining, microcracks initiated and eventually led to the expansion crack of the heat exchanger tube.

关 键 词：双相不锈钢 失效分析 电子探针 氮元素 异常组织 

分 类 号：TG115[金属学及工艺—物理冶金]