摘要
通过宏观和微观分析、硬度测试和管系应力计算分析了某1000 MW超超临界机组主蒸汽取样管泄漏的原因。结果表明:取样管泄漏性质为焊接热影响区Ⅳ型蠕变开裂。其早期失效的主要原因是管系布置的柔性不足导致二次应力过高。提出对T/P91等马氏体钢管道,需重视支吊架的合理设置和维护检修,以防管道发生早期失效。建议对高合金钢焊接接头进行寿命评估时除考虑等效蠕变应力之外,还需考虑应力三轴因子,以提高焊接接头蠕变寿命评估的精度。
The leakage reason of main steam sampling tube of one 1 000 MW USC unit was analyzed by means of macroscopic and microscopic analysis,hardness testing and piping stress calculation.The results showed that the properties of leaking was the typeⅣcracking in heat affected zone.The main reason of early failure was the high secondary stress for the poor flexibility of sampling tube layout.It would be paid attention to the layout of the leading-out tubes.It was suggested that the creep life evaluation of weld should take not only creep strain but also the stress triaxiality factor into account to improve the accuracy of creep life evaluation.
出处
《理化检验（物理分册）》
CAS
2010年第5期316-320,共5页
Physical Testing and Chemical Analysis(Part A:Physical Testing)
基金
中国华能集团科学技术项目(HNKJ04-G04)
