FGH98合金惯性摩擦焊接头显微组织与力学性能

Microstructure and mechanical properties of inertia friction welded joint of FGH98 alloy

采用惯性摩擦焊连接FGH98合金,研究了热处理对FGH98合金惯性摩擦焊接头显微组织以及力学性能的影响。结果表明,原始态焊接接头焊合区主要由γ和γ′两相组成,γ′相在焊接过程中发生了回溶,残余γ′相尺寸和数量均明显降低,经过热处理后,焊合区晶粒尺寸、残余γ′相的尺寸和数量未发生明显变化;原始态焊接接头的焊合区的硬度值最高,在焊合区的中心区域存在硬度降低的现象,热处理态焊接接头显微硬度整体分布相比原始态硬度值未发生较大变化;焊接接头室温拉伸的断裂位置在母材区,屈服强度大于1130 MPa,达到母材的93%以上;抗拉强度大于1616 MPa,达到母材的99%以上;750℃拉伸的断裂位置在焊缝区,屈服强度大于1025 MPa,达到母材的99%以上;抗拉强度大于1197 MPa,达到母材同等水平。

FGH98 alloy was welded by inertia friction welding.The effects of heat treatment on microstructure and mechanical properties of the welded joint were studied.The results show that the weld zone(WZ)of original welded joint is mainly composed ofγphase andγ’phase,the grain size decreases compared with the base metal,γ’phase dissolves back during welding,and the size and quantity of residualγ’phase decreases obviously.The hardness value of the welding area of the as-welded joint is the highest,and the hardness decreases in the central area of the welding area,and the microhardness of the welded joints does not change significantly after heat treatment.The tensile yield strength of welded joint after heat treatment at room temperature is above 1130 MPa,which is more than 93%of that of the base metal.The tensile strength is above 1616 MPa,up to 99%of the base material.While the yield strength at 750℃is above 1025 MPa,more than 99%of the base metal.The tensile strength is above 1197 MPa,reaching the same level of the base material.