Microstructural Evolution of Brazing 304 Stainless Steel Using an Amorphous (Ni, Fe)-based Foil

Microstructural evolution of brazing 304 stainless steel using an amorphous (Ni, Fe)-based foil was studied. Base metals used were 304SS disks with the diameter of 15 mm and 3 mm in thickness. All joined surfaces were ground by SiC papers up to grit 1000 and ultrasonically cleaned by acetone prior to brazing. The results show that the microstructure of the braze joint using VZ-2106 filler foil is different from those using traditional Ni-based braze alloy. Interdiffusion between the VZ-2106 braze and 304SS substrate has little effect on the chemical composition of 304SS substrate close to the brazed joint. The VZ-2106 filler foil demonstrates good result in brazing 304SS. The microstructure of VZ-2106 brazed joint is significantly improved as compared with those of traditional Ni-based brazed specimens. Grain boundary BCrFe precipitates show little effect on tensile strength of the joint.