Combining turning with slide burnishing to improve surface integrity and stress corrosion resistance

Abstract

The surface characteristics play a pivotal role in stress corrosion cracking (SCC) resistance and fatigue life. Strengthening and modifying the material surface properties during manufacturing is a promising approach to improving the component service performance. Therefore, this study proposes a new surface finishing and strengthening mode that combines turning with slide burnishing (TSB) with a common turning tool. The core idea is that the cutting edge of the tool removes the material surface layer as a chip while the tool corner with a large radius performs a slide burnishing process on the manufactured surface. The machining-induced surface integrity in terms of residual stress, surface roughness, micro-hardness and microstructure changes was examined, and the SCC susceptibility was tested in a strong corrosion environment. The results showed that the surfaces processed by TSB suffered lower biaxial residual stresses, higher micro-hardness and deeper hardened layer when compared with the traditional turned surfaces. Besides, it was observed the TSB processed surfaces were less susceptible to SCC initiation which could be attributed to the lower residual stress introduced by TSB. Additionally, the multi-pass TSB treated surfaces showed significant low SCC susceptibility. Consequently, this work suggests that the surface integrity and the service performance like SCC resistance can be improved by TSB.