Mechanical surface treatments effects on corrosion of AISI 316 Ti stainless steel in chloride environments

The current paper investigates effects of various surface treatment techniques such as grinding, garnet blasting, and shot peening on the corrosion rate and behavior of austenite stainless steel of type AISI 316 Ti. The exposure to different corrosive solutions usually accompanying the coastal and industrial environments (sodium chloride and ferric chloride), as well as a combination of the two was considered. The corrosion behavior of AISI 316 Ti under these test conditions was investigated using immersion tests and electrochemical impedance spectroscopy together with optical scanning electron microscopy, in order to observe and to assess the changes in the surface configuration and topography such the shapes, distribution, and dimensions of the resulting pits. The presented results clearly show the relatively higher corrosive effect of ferric chloride, and the increased corrosion rate under greater surface roughness values, which imply greater real surface area and capillarity effects.