Bonding Characterization of 316L and Porous Stainless Steel Thin Pipes by Vacuum Brazing

Abstract:

Vacuum brazing of porous stainless steel tube and 316L stainless steel has been successfully performed using BNi-7 brazing paste as a filler metal. Ni-Cr solid solution and Ni-P intermetallics were the main phases in the brazing seam. And the interface microstructure of the joint was observed by means of SEM and EDS. The experimental results showed that the highest tensile strength of 245 MPa was acquired from the joint brazed at 980℃ for15min. Longer processing time or higher processing temperature than these conditions did not further improve the joint strength. This is ascribed to the interdiffusion between molten liquid of the filler and solid base metal due to concentration gradients.