Visual inspection, SEM/EDS, XRD, oxalic acid etch test, oil extraction technique and oil composition analysis were undertaken determine the causes of the failed valve.

• 研究方法包括目视检查、SEM/EDS、XRD分析，并辅以不锈钢敏化试验及油渍萃取与成分分析技术，综合分析不锈钢阀门之材质劣化原因。