Evaluation of the effect of grain size on chromium carbide precipitation and intergranular corrosion of 316L stainless steel

► Coarsened grains improved the intergranular corrosion resistance of 316L DBJ. ► Intergranular corrosion resistance of 316L increases with increasing grain size. ► Optimizing grain size can be a way to reduce the degree of sensitization of 316L. The effect of grain size on chromium carbide precipitation and sensitization of 316L stainless steel was investigated based on inspection of microstructures and electrochemical potentiokinetic reactivation test. Various grain size samples were produced by heat treating the base material at 1100°C for different durations. The result showed that chromium carbide precipitations were much delayed in larger grains. The degree of sensitization decreases with increasing grain size. The diffusion bonded joint has good resistance to intergranular corrosion due to the coarsened grains and the increased percentage of low energy coincident site lattice, while the grain coarsening is the main contribution.