通过化学成分分析、金相检验、力学性能测试等手段对某电厂超超临界锅炉末级过热器T91钢管爆裂原因进行了分析。结果表明: 爆管系超温运行所致, 过热导致钢管材料显微组织老化、力学性能显著下降; 并根据现场情况对爆裂管的超温原因进行了分析, 认为异物堵塞造成超温的可能性较大。

The bursting and leakage reason of final superheater T91 steel tubes of a ultra super critical boiler was analyzed through chemical compositions analysis, microstructure analysis and mechanical properties test. The results show that the failure of the final superheater tubes was due to overheat which deteriorated the microstructure and mechanical properties of the tubes material. It was believable that the overheat of the bursting tubes was caused by blockage, according to the analysis results on the spot.