Influence of Boron Content on the Tensile Properties and Deformation Behavior of GH3230 Nickel-Based Superalloy

Minor alloying elements play critical roles in the microstructural evolution and mechanical properties of wrought superalloys. The wrought GH3230 Ni-based superalloys with boron (B) contents ranging from 0.0018 to 0.0088 wt.% were prepared by a casting–forging process to investigate the effects of B on microstructure and tensile deformation behavior. The results showed that while the B content had a limited influence on ultimate tensile strength, it significantly improved macroscopic ductility by promoting deformation homogeneity through the modification of carbide morphology and distribution. The carbides exhibited blocky aggregation at low B contents (0.0018–0.0052 wt.%), whereas the formation of uniformly dispersed granular carbides was promoted at higher B contents (0.0066–0.0088 wt.%). Digital image correlation and EBSD analyses revealed that aggregated carbides induced localized deformation and high dislocation density regions, while dispersed granular carbides facilitated homogeneous strain distribution. These findings demonstrate that the B-induced carbide evolution plays a critical role in regulating tensile deformation behavior of GH3230 alloys.