大径厚壁P91三通管焊接及热处理工艺探讨

Discussion on welding and heat treatment process of P91 steel of large thick tee pipe

在防城港电厂600MW级超临界机组安装中,大径厚壁P91三通管管座预留长度过小,传统焊前预热、焊后热处理工艺容易造成应力集中。鉴于此,通过工艺实验和工程实践,探索出一套完全适用类似大径厚壁P91三通管的现场焊前预热、焊接及焊后热处理工艺。

During the installation of Supereritical 600 MW Unit of Fangchenggang Power Plant,a pipe socket on the large thick SA335/P91 steel header was found too short.Under such circumstance,traditional process of preheat and postweld heat treatment might cause stress concentration.Therefore,on the basis of experiments and the engineering practice,a process that is most suitable for preheat and welding and postweld heat treatment on site to treat the weld joint similar to large thick tee pipe （SA335/P91 steel）was explored in this article.