Effect of δ-ferrite on the stress corrosion cracking behavior of 321 stainless steel

The stress corrosion cracking behavior of 321 stainless steel has been studied in high temperature water. Analytical electron microscopy was utilized to characterize the cracking process to better understand the δ-ferrite effect. Results showed that δ-ferrite inhibited the crack growth by changing the cracking direction along the γ/δ boundary and creating a highly branched crack path. δ-ferrite was also a source of Cr to facilitate the formation...