某电厂高温再热蒸汽管道立管管夹尾部发生变形，通过几何尺寸测量、化学成分分析、拉伸试验及热-结构耦合有限元分析等方法，分析了管夹变形的原因。结果表明：管夹在直段与弯曲段的转角处存在应力集中现象，该处等效应力超过相应温度下材料的屈服强度，导致管夹变形；通过增加管夹厚度和在管夹直段与弯曲段的转角处设置肋板，可使其最大等效应力降低至相应温度下材料的屈服强度以下，有效防止管夹变形。

The end of the riser pipe clamp of a high-temperature reheat steam pipe in a power plant was deformed. The reasons for the deformation of pipe clamp were analyzed through geometric measurement, chemical composition analysis, tensile test, and thermal-structure coupled finite element analysis. The results showed that there was a stress concentration phenomenon in pipe clamp at the corners of the straight section and the curved section, and the equivalent stress exceeded the yield strength of the material at corresponding temperature, resulting in deformation of pipe clamp. By increasing the thickness of pipe clamp and setting ribs at the corners of the straight section and the curved section, the maximum equivalent stress could be reduced below yield strength of the material at corresponding temperature, effectively preventing deformation of pipe clamp.