Improvement of IGC resistance of SUS 304 stainless steel by laser surface melting based on grain boundary engineering

LSM and annealing heat treatment on 304 stainless steel resulted in microstructures with high frequency of low ∑ CSL boundaries defined by the coincidence site lattice (CSL) model, especially, twin boundaries (∑3). The maximum frequency of the low Σ CSL boundaries could be 88.6% under optimal processing conditions: 947°C and 28h. The high fraction of the low-∑ CSL boundaries led to a high corrosion resistance to intergranular corrosion.LSM and annealing heat treatment on 304 stainless steel resulted in microstructures with high frequency of low ∑ CSL boundaries defined by the coincidence site lattice (CSL) model, especially, twin boundaries (∑3). The maximum frequency of the low Σ CSL boundaries could be 88.6% under optimal processing conditions: 947°C and 28h. The high fraction of the low-∑ CSL boundaries led to a high corrosion resistance to intergranular corrosion.