某电厂省煤器管在第二次试运行期间发生泄漏。通过宏观检查、化学成分分析、金相检验、扫描电镜及能谱分析对省煤器管泄漏的原因进行了分析。结果表明：省煤器管存在制造缺陷，焊缝热影响区存在的魏氏组织和脱碳层使焊缝脆性增大，原始缺陷裂纹扩展直至造成省煤器管泄漏。

Economizer tube of a power plant leaked during the second trial operation. The leakage cause of economizer tube were analyzed by macroscopic examination, chemical composition analysis, metallographic examination, scanning electron microscope and energy spectrum analysis. The results show that there were manufacturing defects in the economizer tube, widmanstatten structure and decarburization layer in the heat affected zone of the weld joint, which increased the brittleness of the weld joint, and the original crack defects expanded until the economizer tube leaked.