Critical time for non-equilibrium grain boundary segregation of phosphorus in 304L stainless steel

The data obtained by Auger electron spectroscopy for the grain boundary segregation of phosphorus have been reported in 304L stainless steel [C.L. Briant, Metall. Trans. A 16 (1985) 2061; C.L. Briant, Metall. Trans. A 18 (1987) 691]. The results showed that a grain boundary segregation peak of phosphorus appeared at about 24 h during the segregation isotherm at temperature 700 °C, and a segregation peak appeared also at 600 °C for all specimens aged for 100 h at temperatures of 500, 550, 600, 650 and 700 °C after annealing at 1100 °C for 1 h. In this paper these data will be analyzed with the isothermal kinetic model of non-equilibrium grain boundary segregation. It is found from the analysis that peaks are induced by the critical time for non-equilibrium grain boundary segregation of phosphorus.