JOURNAL of the Tunisian Chemical Society

We have studied the dissolution kinetics of stainless steel 17-8 in various H₂SO₄ solutions with concentration varying from 0 to 100% by weight and having a temperature between 40 and 100°C. We find that the kinetics has a maximum corresponding to a [H₂SO₄] max which decreases from 55% at 40°C to 43% at 80°C. The first stage of attack corresponds to a preferential liberation of Cr and Ni. This occurs along a thickness of about 40 µm and can be explained by the continual formation of a passivation layer rich in Cr and Ni. This formation involves a migration of these elements from under layers to the surface.

N. Frini, M. El Maaoui

Pages 233-240