600MW亚临界机组T91钢焊接接头失效分析

600 MW Subcritical Unit T91 Steel Welded Joints Failure Analysis

某电厂600 MW亚临界机组过热器管T91焊接接头泄漏,通过对开裂部位进行一系列试验分析,结果表明,该过热器管焊接工艺执行不严格,使焊缝和热影响区产生粗大淬硬马氏体组织,在多处应力作用下产生热影响区冷裂纹,扩展形成宏观开裂失效。

A power plant 600 MW subcritical unit T91 superheater tubes welded joints leak through cracks parts of a series of tests, the results showed that the superheater tube welding process execution is not strict, the weld and heat affected zone to produce thick quenched hard martensite, resulting in heat affected zone cold cracking under multiple stress, extended to form a macroscopic crack failure.