SA-335 P91钢全位置窄间隙热丝TIG焊接工艺及接头性能研究

针对SA-335 P91钢大口径管环缝,采用轨道式全位置热丝TIG焊机进行了窄间隙焊接。将整条环缝均分为16个区域,根据不同位置熔池受力状态对各区的焊接工艺参数进行修正设置,并对所获焊接接头的组织和性能进行了研究。所获焊缝和热影响区的组织均为回火马氏体,焊接接头的拉伸、弯曲、冲击等力学性能均满足要求。结果表明,窄间隙热丝TIG焊接工艺参数合理,分区修正设置恰当,能够满足SA-335 P91钢大口径管全位置焊接要求。

Study on Welding Procedure and Joint Properties of SA-335 P91 Steel with All-position Narrow Gap Hot Wire TIG

For the circumferential seam of SA-335 P91 steel pipe with large diameter,narrow-gap welding was performed with the orbital type all-position hot wire TIG welding machine. The whole circumferential seam was divided into 16 zones. According to the stress condition of the molten pool at different locations,the welding parameters of each zone were revised. The microstructure and properties of the obtained welded joints were studied. The microstructures of the weld and heat affected zone were all tempered martensite,and the mechanical properties of the welded joint,such as tensile,bending and impact properties,meet the requirements. The results show that the process parameters of narrow-gap hot wire TIG welding were reasonable and the zoning correction settings were appropriate,which can meet the requirements of all-position welding of SA-335 P91 steel pipe with large diameter.