Effect Of Different Thermomechanical Processing On GBCD And IGC Of SUS304

Grain design and control has become a viable means of enhancing the bulk propertied of conventional polycrystalline materials. The widely used SUS304are chosen as model material in this dissertation. The strain in this article would be introduced by laser shocking and cold rolling. High frequency induction heating (HFIH) and laser heat treatment were conducted to replace the traditional heat treatments. This article investigated the effect of different processes on the grain boundary character distribution (GBCD) and the Intergranular Corrosion (IGC) resistance. The energy consumption, treatment time as well as the effect of GBCD was compared. Here are the results:(1) Laser shocking followed by high temperature annealing could modify the GBCD. Long time annealing is beneficial for formation of∑3n. The high laser shocking power is beneficial for boundary migrations. But the excessive shocking power would result in the decrease of fSBs for the increased nucleation of recrystallization would suppress the "multiple twins". The maximum CSL density could reach72%under optimal processing conditions:6J,947℃and20h.(2) An optimized grain boundary character distribution could be achieved by combining cold rolling with HFIH very quickly.5%per-strain and subsequent HFIH at600A for45s produced a sample with a high CSL frequency of75%. The application of a magnetic field would increase the degree of magnetic order which would restrict the recrystallization controlled by diffusion. So the magnetic annealing would restrict the formation of random boundaries.(3) Laser shocking with laser heat treatment could lead to the improvement of the GBCD rapidly which would increase the IGC of the SUS304. The CSL density has stiffened to double its original one under optimal processing conditions:6J-150W-200mm/min double.(4) Cold rolling with HFIH is a low-cost, quick-processing, environmental friendly and effective treatment which is appropriate for industrialized mass production. Laser shocking with laser heat treatment has been applied more widerspread than other thermomechanical treatments for it could cope with the irregular shape and component repairing.