Inconel 601镍基高温合金激光焊焊缝的显微组织

Microstructure of Inconel 601 nickel-based superalloy laser welded joint

对3.0 mm厚的Inconel 601镍基合金激光焊后焊接接头的显微组织进行研究。结果表明:凝固后焊缝金属仍呈奥氏体相,其相组成由奥氏体基体γ相、γ′相(Ni3Al为主)以及碳化物相(Cr23C6)组成。同时,熔池金属以交互结晶的方式优先依附在半熔化状态的母材晶粒表面生长。另外,在焊缝金属中观察到以胞状和树枝状为主的亚结构,亚结构中存在凝固亚晶界、凝固晶粒边界和迁移晶粒边界。

The welded joint microstructure of 3.0 mm-thickness Inconel 601 superalloy was analyzed. The results show that the phase composition of the welded joint consists of austenite matrix γ phase, γ＇ phase （Ni3Al-based） and carbide phase （Cr23C6）, which is similar with the metal phase composition. And the molten pool metal grows up in the form of interaction crystallization, which is prior to attach to the semi-molten state of the metal surface. The cellular and dendritic substructures are observed in the welded joint microstructures. Solidification sub-grain boundary （SSGB）, solidification grain boundary （SGB） and migrated grain boundary （MGB） exist in the substructure.