超临界机组轴封冷却器TP304不锈钢管泄漏原因分析  

Analysis on Leakage Cause of TP304 Stainless Steel Tube in Gland Steam Condenser of USC Units

作　　者：田晓[1] 肖国华[1] 李益民[1] 杨百勋[1] 

机构地区：[1]西安热工研究院有限公司,西安710043

出　　处：《理化检验（物理分册）》2013年第1期64-67,70,共5页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：通过宏观检验、化学成分分析、拉伸试验、压扁试验、晶间腐蚀试验、金相检验、扫描电镜及能谱分析等方法,对某电厂汽轮机轴封冷却器TP304不锈钢管的泄漏问题进行了分析。结果表明:TP304不锈钢管在外表面残余拉应力和蒸汽中Cl-,S2-的联合作用下,经过一定时间因发生严重应力腐蚀导致管子开裂。对此,提出了消除TP304不锈钢焊管表面残余应力、严格控制汽水品质、降低有害离子含量等建议。The leakage cause of TP304 stainless steel tube in gland steam condenser of USC units was investi- gated by means of macroscopic observation, chemical composition analysis, tensile test, flattening test, intergranu- lar corrosion test, metallographic examination, SEM and EDS analysis. The results showed that the leakage of TP304 stainless steel tube was caused by stress corrosion under the joint action of surface residual stress and corro- sive medium CI , S2- in steam. For this, preventive measures, such as relieving surface residual stress, strictly controlling boiler steam-water quality, reducing the content of harmful irons, have been put forward.

关 键 词：轴封冷却器 TP304不锈钢 应力腐蚀 裂纹 

分 类 号：TK223.3[动力工程及工程热物理—动力机械及工程] TG115[金属学及工艺—物理冶金]