Diffusion bonding of AISI 304L steel to low-carbon steel with AISI 304L steel interlayer

The diffusion bonding (DB) of AISI 304L to low carbon steel with an AISI 304L interlayer was attempted at temperatures of 850, 900, and 950 °C, with a 90-min holding time at a pressure of 10 MPa. The tensile test revealed that the transition joints achieved a maximum tensile strength of 340.5 MPa. The microhardness test carried out on the diffusion-bonded samples revealed the formation of more hard and brittle phases at higher temperatures. Optical micrographs and scanning electron microscopy (SEM) images showed the grain growth, the width of the diffused region and the fine details of the interface structure. The tensile strength of the diffusion bonded joints was not affected due to the formation of intermetallic compounds at the interface because the fracture took place in the base metal low carbon steel.

► Maximum tensile strength of 340.5 MPa for the samples processed at 900 °C. ► SEM image revealed variation in pearlite distribution. ► Diffusion coefficient values were estimated for Cr, Ni and Mn. ► XRD reports revealed formation of Mn3Si, Cr3Ni5Si2, and α phase in the interface.