T91钢TIG+MIG焊接接头性能及组织

Mechanical properties and microstructure of TIG+MIG welded joint of T91 steel

摘要: 对采用TIG+MIG焊的T91钢焊接接头进行了力学性能、持久强度和高温时效试验,并对T91钢TIG+MIG焊接接头的显微组织及断口的断裂特征进行了观察和分析。结果表明,T91钢TIG+MIG焊接接头的韧脆转变温度(FATT)为-13℃,625℃17958h高温持久试验为70MPa,外推10⁵h高温持久强度为46.48MPa。焊接接头的高温性能取决于其组织的变化,以MC₂₃C₆为主的合金碳化物对持久强度起了重要作用。

Abstract: The mechanical properties, creep strength and high temperature ageing of TIG+MIG welded joint of T91 steel were tested. Microstructure and fracture morphology of the joint was analyzed. The creep strength of 625℃ for 17958 h is 70 MPa, which can deduce that the sustained strength after 10⁵ h is 46.5 MPa and the FATT is -13℃. It is proved that the properties of TIG+MIG welding joint at high temperature is determined by the change of microstructure. Furthermore, M₂₃C₆ plays an important role.