Incoloy 925 joints of 5 mm thick were accomplished by adopting high energy density, electron beam welding (EBW) process. Although the weld seam microstructure was completely austenitic and free from solidification cracking, the heat-affected zone (HAZ) of EBW joints experienced liquation cracking. The mechanical behaviour of the EB weld seams in the as-welded and direct aged (DA) at 732 °C for 4 h and air-cooled conditions were compared. Electron backscattered X-ray diffraction (EBSD) analysis revealed the formation of strengthening precipitate γ′ in the matrix and the precipitation of sigma (σ) phase, M₇C₃, M₂₃C₆ and Ti-rich carbides formed along the crystallite boundaries in the DA condition. The tensile property outcomes opined that the joint efficiency of the weld seams in the DA condition (99.32 %) was found to be better than the ones in the as-welded condition (71.32 %). Also, the yield strength has been considerably improved in the EB weld seams subjected to DA conditions. The carbide precipitation along the grain boundaries is discontinuous and also not effective in pinning the dislocations under impact loads.

采用高能量密度电子束焊接（EBW）工艺完成了5毫米厚的Incoloy 925接头。尽管焊缝组织是完全奥氏体的，并且没有凝固裂纹，但是EBW接头的热影响区（HAZ）发生了液化裂纹。比较了电焊和直接时效（DA）在732°C下4 h和空冷条件下的EB焊缝的力学行为。电子背散射X射线衍射（EBSD）分析表明，在基质中形成了增强的沉淀γ'，并沉淀了σ（σ）相，M ₇ C ₃，M ₂₃ C ₆在DA条件下，沿晶界形成了富钛碳化物。拉伸性能结果表明，在DA条件下焊缝的接头效率（99.32％）优于在焊接状态下的焊缝接头效率（71.32％）。而且，在经受DA条件的EB焊缝中，屈服强度得到了显着提高。沿晶界的碳化物沉淀是不连续的，并且在冲击载荷下也不能有效地固定位错。