Novel observation of dominant role of strain rate over strain during pre-straining on corrosion behaviour of 304L austenitic stainless steel

Abstract

Pre-straining at different strain-rate is usually carried out during forming of 304L stainless steel (SS) which can affect its corrosion behaviour. A systematic study on the effect of strain-rate in conjunction with pre-strain on electrochemical corrosion behaviour of 304L SS is elucidated for the first time. Prior deformation (10% and 30%) resulted in either beneficial or detrimental effect on the corrosion and pitting resistance depending up on the imposed strain-rate. A novel observation of improved corrosion resistance at higher strain-rate is attributed to differences in strain-rate dependent evolution of microstructure and substructure. This work suggests that the corrosion behaviour of 304L SS is a stronger function of strain-rate compared to the strain and from the microstructure viewpoint, it depends on the complex interplay between dislocation density, deformation-induced martensite, coincidence site lattice (CSL) boundary and, crystallographic texture.