Corrosion behavior of stainless steel-tungsten carbide joints brazed with AgCuX (X = In, Ti) alloys

We studied the long-term corrosion behavior of carbide/316L stainless steel joints brazed with AgCuX alloys (X = Ti, In). The results show that the Cu-based solid solution (Cu (s,s)) in the brazing alloy is the weak link of corrosion germination. Ti increases the Fermi level and decreases the *H adsorption energy (delta G(*H)) of Cu(s,s), thus leading to a higher thermodynamic tendency of hydrogen evolution. In contrast, In decreases the Fermi level and the d band center of Cu (s, s) leading to a positive delta G(*H), which improves the corrosion resistance. The results agree with the mechanical performance tests.

Automated summary

The Cu-based solid solution in the brazing alloy is found to be the weak point for corrosion initiation. Titanium increases the thermodynamic tendency of hydrogen evolution, while indium improves the corrosion resistance.