高压换热器TP347焊缝开裂失效分析  

Cracking Failure Analysis of TP347 Weld of High Pressure Heat Exchanger

作　　者：魏薇 黄国根 章芳芳 WEI Wei;HUANG Guogen;ZHANG Fangfang(Zhejiang Academy of Special Equipment Science,Hangzhou 310020,China;Key Laboratory of Special Equipment Safety Testing Technology of Zhejiang Province,Hangzhou 310020,China)

机构地区：[1]浙江省特种设备科学研究院,浙江杭州310020 [2]浙江省特种设备安全检测技术研究重点实验室,浙江杭州310020

出　　处：《热加工工艺》2020年第17期159-162,共4页Hot Working Technology

基　　金：浙江省质监系统NQI科研计划(20180109)。

摘　　要：通过宏观检查、显微组织观察、断口扫描及能谱分析、硬度测试、化学成分分析等多种手段,研究了某柴油加氢装置高压换热器用进出口管线TP347焊缝开裂的原因。结果表明:该裂纹为焊接热裂纹,产生原因是焊接温度过高、线能量不均匀、焊条质量不稳定,造成显微组织不均匀,产生过大的残余应力,而且δ铁素体含量过少,碳化铌沿晶界析出和出现全奥氏体组织,抗热裂纹能力降低。The cracking causes of the TP347 weld on inlet and outlet pipes of a high pressure heat exchanger was studied by means of macro-morphology observation,microstructure observation,fracture analysis,EDS analysis,hardness test and chemical composition analysis.The results indicate that the cracks are welding hot crack.Because the welding temperature is too high,the line energy is not uniform,the welding rod quality is not stable,the microstructure is not uniform,the residual stress is too large,and the content ofδferrite is too small,the niobium carbide precipitates along the grain boundary and appears the whole austenite structure,and the ability to resist thermal cracks is reduced.

关 键 词：TP347焊缝 焊接热裂纹 Δ铁素体 残余应力 碳化铌 

分 类 号：TG142.71[一般工业技术—材料科学与工程] TG441.7[金属学及工艺—金属材料]