The effect of impact and continuous scratches on the corrosive wear behavior of Fe-18%Cr-5%Ni alloy and 304 stainless steel for two grain sizes

The transient current response (TCR) in Fe-18%Cr-5%Ni alloy (referred to as the alloy from here on) and 304 stainless steel (SS) due to impact and continuous scratching in an electrolye has been studied using scratch technique. The smaller grain size produces higher values of transient current due to the corrosive wear process in both materials. The additional factor affecting the TCR during continuous scratching is the number of tracks developed by the stylus. The microstructural details, e.g. twins, appear to affect the transient current values. The transmission electron microscopy reveals the near surface (close to the scratches) microstructures showing the presence of deformation twins in 304 SS, while nonuniform distribution of dislocations give rise to the dislocation cell structure in the alloy. The microstructural features such as grain boundaries, isolated dislocations, cell and twin boundaries have been related to the TCR generation in the alloy and the 304 SS.