Strengthened forced convection – A novel method for improving the pitting corrosion resistance of friction-surfaced stainless steel coating

Abstract

During friction surfacing (FS), argon is commonly used as shielding gas for avoiding oxidation, and the resistance of FSed 316L coatings to pitting corrosion is normally improved by the fragmentation of MnS inclusions. In the present study, it is demonstrated that the resistance of the FSed coating to pitting corrosion could be further improved using strengthened forced convection (SFC) with argon shielding. Restoration and further growth of dynamically recrystallized grains under SFC relieve the elastic strain in {111} grains, decrease the dislocation density, and hence reduce the metastable pit initiation probability effectively and suppress the stable pit transition susceptibility slightly. Keywords: Pitting corrosion, Austenitic stainless steel, Friction surfacing, Dynamic recrystallization, Shielding gas