Corrosion resistance of bonding zone of AISI 316L–304 stainless steels joined with iron based glass ribbon interlayer: Microstructural effects

Abstract

The effect of holding time on the microstructure and corrosion resistance of the junction zone of AISI 316L bonded to AISI 304 stainless steels (SSs) at 960°C using an Fe based alloy filler was investigated. Samples of austenitic SSs were joined in a sandwich-like arrangement using non-commercial Fe₆₀Ni₁₂Cr₈P₁₃B₇ metallic glass ribbon. Microstructural analysis revealed significant dissolution of the amorphous ribbon in both SSs for short holding times, exhibiting a narrow interlayer with very fine precipitates. Larger holding times induced widening of the interlayer and coarsening of γ precipitates in the iron based alloy and significant variation of the interlayer chemical composition. Microstructural dissimilarity of the bonding zone promoted selective dissolution coupled with crevice corrosion of the joints in 3·5 wt-% sodium chloride solution. In general, at the joining temperature of 960°C, the bonding ribbon and the AISI 316L SS presented higher corrosion resistance as the holding time increased up to 20 min.