Statistical analysis of the pitting corrosion induced by potentiostatic pulse tests of wrought and SLM 316L stainless steels

An original approach coupling potentiostatic pulse tests and statistical analysis of the pitting features was carried out to compare the sensitivity to pitting corrosion of wrought and SLM 316L SS (stainless steels). The measurement and analysis of current densities during potentiostatic pulse tests has led to a better understanding of the pitting corrosion behavior of wrought and SLM 316L SS in 4 mol.l-1 NaCl solution at 50 °C. The association of global measurements and local observations showed that the two stainless steels exhibit different pitting mechanisms. Moreover, a slightly different susceptibility to pitting corrosion is found between the direction of manufacture and the normal direction for the 316L SLM with these tests. The role of the microstructure and the passive film in the pitting corrosion behavior is discussed