Study for corrosion characteristics of ferritic stainless steel weld metal with respect to added contents of Ti and Nb

This paper identified the effects of Ti and Nb on pitting and intergranular corrosion resistance in a ferritic stainless steel weld metal of the automobile exhaust system. We fabricated 4 flux cored wires designed with 0–0.2 wt% Ti and 0–1.0 wt% Nb and performed Flux Cored Arc Welding. Through the potentiodynamic polarization test in 0.5M NaCl, we evaluated pitting resistance. And in order to evaluate the intergranular corrosion resistance, we observed microstructure after we performed DL-EPR test in 0.5M H2SO4+0.01M KSCN. As a result of the test, the specimen added with 0.2%Ti+1.0%Nb showed the highest pitting resistance. From observing the degree of sensitization and microstructure, the intergranular corrosion resistance was higher as the contents of Ti and Nb increased. And through EBSD we observed Cr carbide which affects the corrosion resistance.