Inconel 690/S32101异种合金搭接接头的组织与性能

Microstructures and mechanical properties of Inconel 690/S32101 dissimilar lap joints

采用氩弧焊将镍基Inconel 690合金覆板以搭接的形式,焊接于新型乏燃料水池材料双相不锈钢S32101的表面,并对比自熔焊和填充焊两种工艺对接头显微组织及力学性能的影响.结果表明,在合理的工艺条件下,两种工艺均可以获得成形良好的搭接接头,但填充焊可得到更大的搭接宽度,其抗拉强度最高可达538 MPa.焊后检测发现,焊缝组织主要由胞状晶所组成,其间分布有颗粒状铁素体析出物.两侧熔合线处呈现不同的结晶形貌,Inconel 690覆板侧具有明显的外延生长组织,而S32101侧则出现平面晶结构.与自熔焊相比,填充焊热影响区中奥氏体溶解现象仅出现在熔合线附近极小的范围内.

The GTAW(gas tungsten arc welding) was employed to weld Inconel 690 nickel-based alloy overlay plate and S32101 duplex stainless-steel, a new type material for fabricating spent fuel pool, with lap joint. Microstructures and mechanical properties of the joints fabricated with autogenous welding and filler welding were comparative studied.Compared with autogenous welding, a sound bead, with larger lap width and the tensile strength of 538 MPa, was obtained by filler welding under the optimized welding parameters. The welds were characteristic of cellular grains and fine ferritic precipitates dispersed among them. Different solidification microstructures were presented at fusion boundaries within weld. Epitaxial growth can be observed in the side of Inconel 690 and planar growth in the other side. Austenite dissolution range in the heat affected zone of the filler welding is narrower than that of autogenous welding.