Abstract: To optimize the manufacturing process and improve the service reliability of S32750 super duplex stainless steel heat exchange tubes, this study subjected the steel tubes to heat treatment at 1 050 ℃, 1 070 ℃, and 1 095 ℃ respectively. The surface hardness and ferrite (α-phase) content of the material under different heat treatment conditions were systematically tested. Subsequently, tube expansion with deformation ratios of 1%, 1.2%, 1.6%, 2.1%, and 2.6% were applied to the heat-treated samples. Corrosion tests were conducted in boiling magnesium chloride solution (155±1) ℃ to observe and record the stress corrosion crack initiation time and crack length of the samples, and the crack growth rate was calculated. The results show that as the heat treatment temperature increased, the surface hardness of S32750 steel gradually decreased, while the ferrite (α-phase) content increased significantly. No stress corrosion occurred in the material without applied deformation, but stress corrosion appeared after deformation was applied, and the larger the deformation ratio, the earlier the crack initiation time. When the heat treatment temperature was 1 050 ℃, the volume fraction ratio of ferrite (α-phase) to austenite (γ-phase) was close to 1∶1, and the material exhibits the lowest corrosion rate. The optimal process parameters for heat-treatment and tube expansion processing for S32750 steel tubes were: heat treatment temperature of 1 050 ℃, and deformation ratio within the range of 1.2%-2.1%.