What question did this study set out to answer?

This study aims to analyze the failure mechanisms of dissimilar steel joints in a supercritical boiler's high-temperature reheater and propose management solutions.

May 29, 2026Open Access

660mw 超超临界锅炉高温再热器异种钢接头治理技术研究

Key Points

This study aims to analyze the failure mechanisms of dissimilar steel joints in a supercritical boiler's high-temperature reheater and propose management solutions.
Investigated a leakage incident at a specific coal-fired power plant's supercritical boiler
Analyzed failure causes related to oxidation rate, thermal expansion mismatch, and welding process
Proposed a transition pipe solution using SA-213T91Type1 with enhanced welding and inspection standards
Identified that oxidation voids and microcracks contributed to leaks due to material mismatches
Proposed management system demonstrated effectiveness in preventing failures in similar systems
Provided technical reference for safe operation of supercritical boiler high-temperature reheaters

Abstract

超超临界锅炉作为火力发电的核心设备，其高温再热器长期在高温、高压及交变应力工况下运行，异种钢接头因材料特性差异易成为故障高发部位。本文以某火力发电厂 #2 锅炉（DG-1967/28.25-II 型，660MW 超超临界参数）高温再热器泄漏事故为研究对象，通过分析事故原因，明确 12Cr1MoVG 与奥氏体不锈钢（TP310HCbN、 S30432）异种钢接头因氧化速率差异、膨胀系数不匹配及焊接工艺管控不足，导致熔合线处产生氧化缺口与微裂纹，最终引发泄漏。基于此，提出插入 SA-213T91Type1 过渡管的改造方案，结合严格的焊接工艺、热处理及检测标准，形成完整的异种钢接头治理体系。实践表明，该方案可有效解决异种钢接头开裂问题，为同类型超超临界锅炉高温再热器的安全稳定运行提供技术参考。

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