某电厂TP304不锈钢换热管裂纹分析

Crack Analysis of TP304 Stainless Recuperator Tube in a Power Plant

某电厂汽轮机汽封加热器的TP304换热管出现裂纹,对已泄漏的换热管取样分析,TP304不锈钢管的化学成分和力学性能都符合技术条件要求,有应力腐蚀倾向,裂纹附近有较大拉应力,裂口表面含有Cl离子和Na离子等腐蚀介质,TP304管是由于应力腐蚀引起的开裂。

Crack was discovered on TP304 recuperator tube of a turbine steam seal healer in a power plant. Samples were collected and analyzed from these tubes which leakage happened and tile following conclusions were approached： Tbe composition and mechanical properties of TP304 stainless steel tube meet specification. TP304 was subjected to stress corrosion. Near the crack large tensile stress exist; Corrosion medium such as Cl- and Na＋ can be observed on the surface of the crack. Titus the cracking of the tube was cased by stress corrosion.