某火电厂锅炉末级再热器T23/TP347H异种钢接头异常组织分析
|
摘要
某火电厂锅炉末级再热器异种钢接头(T23/TP347H)在割管检验中发现TP347H侧内壁坡口位置存在长约1.1 mm、宽0.5 mm的异常组织区域。对该接头进行了金相组织分析、扫描电镜分析、能谱分析、机械性能试验和当量温度计算。根据试验结果分析得出:该异常组织区域应为在打底焊时选用错误焊丝,发现选用错误焊丝后未能将打底焊焊丝金属清除干净,然后选用TP347H正常焊丝在此基础上继续焊接,从而在焊缝根部残留错误焊丝组织。根据试验结果给出相应的改进建议。
Abnormal microstructure area in TP347 H side inner wall groove of a T23/TP347 Hdissimilar steel joint of final reheater of boiler in a thermal power plant was found in the pipe cutting test process, this area is about 1.1 mm long and 0.5mm wide. The dissimilar steel joint was analyzed by metallographic analysis, scanning electron microscopy, energy spectrum analysis, mechanical properties test, and equivalent temperature calculation. The analysis results show that the reason of the abnormal microstructure is that wrong type of wire is selected during the backing welding, and the metal of welding wire isn't cleaned up completely, then the right welding wire of TP347 H is used to weld on the basis of wrong welding wire. Thereforc the microstructure of wrong welding wire is retained in the root of the weld. Finally, improvement suggestions are given according to the test results.
Abnormal microstructure area in TP347 H side inner wall groove of a T23/TP347 Hdissimilar steel joint of final reheater of boiler in a thermal power plant was found in the pipe cutting test process, this area is about 1.1 mm long and 0.5mm wide. The dissimilar steel joint was analyzed by metallographic analysis, scanning electron microscopy, energy spectrum analysis, mechanical properties test, and equivalent temperature calculation. The analysis results show that the reason of the abnormal microstructure is that wrong type of wire is selected during the backing welding, and the metal of welding wire isn't cleaned up completely, then the right welding wire of TP347 H is used to weld on the basis of wrong welding wire. Thereforc the microstructure of wrong welding wire is retained in the root of the weld. Finally, improvement suggestions are given according to the test results.
引文
[1]贾非.秦皇岛发电有限责任公司1号锅炉再热器垂直管组寿命诊断[J].电站系统工程,2009,25(2):41-42.
[2]龙会国,龙毅陈,红冬.高温再热器T23/12Cr1MoV异种钢焊缝失效机理[J].中国电力,2011,44(5):70-73.
[3]肖国振,尹成武,朱平,等.超临界锅炉末级过热器T23管性能状态评估及监督管理[J].锅炉技术,2013,44(1):63-66.
[4]国家能源局.火力发电厂金属材料选用导则:DL/T 715-2015[S].北京:中国电力出版社,2016.
[5]中华人民共和国国家质量监督检验检疫总局,中国国家标准化管理委员会.不锈钢焊丝和焊带:GB/T29713-2013[S].北京:中国标准出版社,2013.
[6]章亚林.奥氏体/贝氏体异种钢接头运行早中期组织性能分析[J].热力发电,2002(1):28-30.
[2]龙会国,龙毅陈,红冬.高温再热器T23/12Cr1MoV异种钢焊缝失效机理[J].中国电力,2011,44(5):70-73.
[3]肖国振,尹成武,朱平,等.超临界锅炉末级过热器T23管性能状态评估及监督管理[J].锅炉技术,2013,44(1):63-66.
[4]国家能源局.火力发电厂金属材料选用导则:DL/T 715-2015[S].北京:中国电力出版社,2016.
[5]中华人民共和国国家质量监督检验检疫总局,中国国家标准化管理委员会.不锈钢焊丝和焊带:GB/T29713-2013[S].北京:中国标准出版社,2013.
[6]章亚林.奥氏体/贝氏体异种钢接头运行早中期组织性能分析[J].热力发电,2002(1):28-30.