CAJ | 학술논문

某300 MW 火电机组运行中发生汽动给水泵0Cr13Ni4Mo 不锈钢主轴断裂事故。通过化学成分分析、力学性能测试、显微组织分析及断口形貌分析等方法对其断裂原因进行了分析。结果表明：给水泵主轴断裂是由于其表面镀铬处理使得镀铬层内形成众多垂直于轴基体的微裂纹，不仅降低了材料的疲劳强度，并为轴体开裂提供了众多的裂纹源，这些微裂纹在扭转循环载荷作用下向基体内部不断疲劳扩展直至断裂。
모300 MW 화전궤조운행중발생기동급수빙0Cr13Ni4Mo 불수강주축단렬사고。통과화학성분분석、역학성능측시、현미조직분석급단구형모분석등방법대기단렬원인진행료분석。결과표명：급수빙주축단렬시유우기표면도락처리사득도락층내형성음다수직우축기체적미렬문，불부강저료재료적피로강도，병위축체개렬제공료음다적렬문원，저사미렬문재뉴전순배재하작용하향기체내부불단피로확전직지단렬。
The 0Cr13Ni4Mo stainless steel shaft of a steam feed pump of a 300 MW thermal power unit fractured during service.The investigation for the failure including chemical compositions analysis,mechanical properties test,microstructure observation and fracture pattern examination of the shaft was taken to find out the fracture reasons.The results show that there were many micro cracks vertical to base body in the surface chromium coating of the shaft because of chromizing treatment,which not only reduced the fatigue strength of the shaft,but also provided many cracking sources.Under the action of cycled torsion loading,micro cracks in the chromium coating extended continuously to base body of the shaft until fracture.