Product Code: ICA11_P116

Effect of Laser Shocking on Intergranular Corrosion Resistance of 304 Type Austenite Stainless Steel
Authors:
Sen Yang, Nanjing University of Scinece and Technology; Nanjing Peoples Republic of China
Presented at ICALEO 2011

Grain boundary engineering (GBE) became a viable means of enhancing the bulk properties of conventional polycrystalline materials. In fact, intergranular corrosion (IGC) starts from surface and gradually penetrates into interior of the component. Therefore, grain boundary engineering the near surface of the specimens will benefit for improvement of IGC resistance.
The aim of this presentation is to investigate the effect of laser shocking and annealing treatment on the near surface microstructure and IGC resistance of 304 austenite stainless steel. The experimental results showed that laser shocked specimens became much more susceptible to IGC, and the corrosion rate was even higher than that of the base materials under the same sensitization condition. However, the subsequent annealing treatment changed the near surface microstructure of specimens, which resulted in the remarkable improvement of the IGC resistance. The reason could be ascribed to formation of a high frequency of low energy CSL boundaries, which made the continuous random boundaries network discrete and restricted IGC cracks from propagating into interior of specimens.