Enhancing the surface integrity and SCC resistance of 304 austenitic stainless steel by pre-stress grinding

Abstract

In order to improve the surface integrity and enhance stress corrosion crack (SCC) resistance of stainless steel (SS) materials, this study investigates the application of pre-stress grinding (PG) technique. The impact of PG on various surface integrity parameters, including residual stress, surface topography, surface roughness, and microstructure, is examined. Additionally, the SCC behavior of the ground surface is evaluated and compared under different levels of pre-stress applied during PG. Experimental results demonstrate that the integrity of the PG-treated surface is significantly improved, leading to enhanced SCC resistance. This enhancement can be attributed to the additional compression effect generated by the applied pre-stress, as well as the increased surface rigidity of the material. Furthermore, numerical analyses indicate higher temperatures and lower plastic strain rates during PG, which effectively inhibit the martensitic phase transformation. However, it is important to note that the strengthening effect of pre-stress may have an upper limit, thus higher pre-stress values are not necessarily more advantageous, and it is crucial to ensure that the applied stress does not exceed the yield strength of the material. Additionally, achieving an ultrafine-grained surface requires the implementation of more aggressive grinding parameters.