通过宏观检查、化学成分、力学性能、显微组织及扫描电镜与能谱分析,结合设计、制造、安装等阶段存在的隐患分析,深入研究了某电厂SA213-TP347H高温再热器管频繁爆管原因。结果表明:高温再热器管子在弯管处存在不同程度的机械损伤缺陷。爆管管样化学成分、硬度、拉伸性能符合ASTM A213/A213M的规定;爆口处显微组织为奥氏体,晶界处存在含Cr和Nb成分析出物。备品备件硬度偏高,显微组织有明显的孪晶和较多滑移线,加速了敏化,晶界急剧贫Cr化。综上分析,高再频繁爆管的原因既有设计上的因素,也有制造质量的影响,而弯管未进行固溶处理,加速了贫Cr区的形成从而导致晶界抗腐蚀性能降低,导致晶间腐蚀所引起。 Through the macroscopic inspection, chemical composition, mechanical properties, microstructure and SEM and EDS, combined with the hidden danger analysis in the design, manufacture and installation stages, the author deeply studied the frequent squib of SA213-TP347H high temperature reheater tube the reason. The results show that there are some mechanical damage defects in the pipe of high temperature reheater pipe. The chemical composition, hardness and tensile properties of the explosive pipe sample conform to the requirements of ASTM A213 / A213M; the microstructure of the explosive orifice is austenite, and the precipitates containing Cr and Nb components exist in the grain boundary. Spare parts hardness is high, the microstructure has obvious twins and more slip lines, accelerated sensitization, the grain boundary sharp depletion of Cr. In summary, the causes of high frequent reclosing have both design and manufacturing quality effects, while the elbows have not been solution treated, accelerating the formation of depleted Cr regions, leading to a decrease in grain boundary corrosion resistance resulting in Intergranular corrosion caused.