废热锅炉管束应力腐蚀失效分析

The Failure Analysis of Stress Corrosion of Waste Heat Boiler Tube Bundle

某化工公司废热锅炉在运行期间U型换热管发生泄漏失效。经过对试样化学成分、宏微观断口和能谱检测,结合废热锅炉运行环境对换热管失效原因进行了综合分析。结果表明高温水中Cl-引起的应力腐蚀开裂是其失效的主要原因,控制废热锅炉制造过程中管道残余应力水平及锅炉给水中Cl、S含量是防止废热锅炉发生类似失效的措施。

The U-type pipe of waste heat boiler in One Chemical Company had a leakage in the operation.After the chemical composition analysis,macro and micro fracture analysis and energy spectrum detection to the sample,connecting with the comprehensively analysis of the operation environment,it results that the stress corrosion cracking caused by Cl ingredients in boiler water is the main cause of its failure.To control the residual stress level of pipe in manufacturing process of waste heat boiler,Cl and S content in boiler water are good methods to prevent the occurrence of similar failure.