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The effect of boron (B) on stress corrosion resistance of S31254 in the presence of residual stresses has been studied. The microstructure and corrosion resistance of S31254 containing B at different levels of cold deformation are analyzed in this study. In the results, it is shown that B favors the improvement of deformation uniformity of S31254. The grain boundary (GB) and slip bands have better corrosion resistance at 5% deformation, and the overall corrosion resistance is better than that of the undeformed state, with smaller passivation current density and narrower width of GB corrosion grooves, especially for the 40B samples. At 30% deformation, the overall corrosion resistance of 40B S31254 is better than 0B due to improved deformation uniformity. [ABSTRACT FROM AUTHOR]

The aim of the present work was to evaluate initial secondary austenite phase microstructural changes (δ → γ′) in 2205 duplex stainless steel with N content of 0.36 wt% during hot tensile test. The results showed there is no secondary austenite microstructural change in zero deformation degree. The secondary austenite (γ2) phase transformation occurred only in the cooling process and under hot deformation condition. Initial secondary austenite (γ′) occurred within the ferrite matrix at the temperature range of 950-1150 °C. The precipitation of initial γ′ increased with the increase in aging time and deformation degree. With increasing time, a progressive transformation of initial γ′ to γ2 occurred. The orientation relationship between the initial γ′ phase and the δ matrix was different at varying high temperatures. A significant change in the hot deformation condition has been observed as a consequence of secondary austenite reformation. These results indicated the importance of control over the shape and volume fraction of secondary austenite phases on high nitrogen duplex stainless steels to improve hot ductility. [ABSTRACT FROM AUTHOR]