Role of MnS in the intergranular corrosion and depassivation of sensitized Type 304 stainless steel
Noriyuki Ida, Masashi Nishimoto, Izumi Muto, Yu Sugawara
Abstract
Abstract During polarization in 1 M NaCl (pH 5.4), intergranular corrosion of sensitized re-sulfurized Type 304 stainless steel occurred after pit initiation at MnS inclusions. Intergranular corrosion occurred when the pitting corrosion reached a Cr-depleted region along the sensitized grain boundaries. During depassivation under open-circuit conditions in 1 M NaCl (pH 1.0), MnS dissolution occurred as the first step, and the second step was the initiation of intergranular corrosion. Finally, dissolution of the steel matrix occurred. The role of MnS in the initiation of intergranular corrosion and depassivation of sensitized steel is discussed.
Topics & Concepts
Intergranular corrosionMetallurgyMaterials scienceDissolutionPitting corrosionCorrosionGrain boundaryMicrostructureChemistryPhysical chemistryHydrogen embrittlement and corrosion behaviors in metalsCorrosion Behavior and InhibitionWelding Techniques and Residual Stresses