12Cr1MoVG焊接接头在役时长对显微组织的影响及分析

Effect of In-service Time on Microstructure of 12Cr1MoVG Welded Joint

本文重点研究了高温在役时长对12Cr1MoVG锅炉主蒸汽管道的焊接接头显微组织,探讨了显微组织变化的原因,分析了焊接接头贝氏体球化的原因。结果表明随着使用时间增加,贝氏体发生球化,逐渐分布在α-铁素体中,使用时间越长,球化程度越严重。分析发现原子扩散是球化的主要形成原因,合金元素可以减缓球化行为。珠光体或贝氏体球化检测对锅炉安全使用非常重要。

This paper focus on the microstructure of the welded joint of main steam pipe that made by 12Cr1MoVG in-service time at high temperature,discusses the cause of change in microstructure,analyzes the mechanism of Bainite spheroidization which exist in welded joint.The result shows that the Bainite spheroidizes and gradually distributes inα-ferrite with the increase of in-service time.The spheroidization becomes more serious with the time increasing.It is found that atomic diffusion is the main cause of spheroidization and the spheroidization can be slowed down by alloying elements.The spheroidization of pearlite or bainite is very important for boiler safety.