Pitting corrosion behavior on crack property in AISI 304L weld metals with varying Cr/Ni equivalent ratio

The pitting corrosion behavior on welded joints of AISI 304L austenitic stainless steel was investigated with the flux-cored arc welding (FCAW) process. The dependence of pitting corrosion susceptibility on the microstructure and constituents was compared in weld metals by using three newly designed filler wires. Mechanical examination demonstrated that the tensile and yield strengths were increased with increasing equivalent weight ratio of chromium/nickel (Creq/Nieq). Ductility-dip cracking (DDC) was observed in the fully austenitic structure in the deposited metal, and it detrimentally affected the pitting resistance. Potentiodynamic anodic polarization results revealed that the passive film breakdown was initiated in the crack opening, and that the concentration of chloride ions and corrosion products induced severe damage near to the DDC.