Rapid nickel diffusion in cold-worked type 316 austenitic steel at 360–500 °C

Abstract The diffusion coefficient of nickel in cold-worked Type 316 austenitic steel was determined by the diffusion couple method in the temperature range between 360 and 500 °C. A diffusion couple was prepared by electroless nickel plating on the surface of a 20 % cold-worked Type 316 austenitic steel specimen. The growth in width of the interdiffusion zone was proportional to the square root of diffusion time until 14 055 h. The diffusion coefficient of nickel (DNi) in cold-worked Type 316 austenitic steel was determined by extrapolating the concentration-dependent interdiffusion coefficient to 11 at.% of nickel. The value of DNi at 360 °C was about 5 000 times higher than the lattice diffusion coefficient of nickel in Type 316 austenitic steel. The determined activation energy 117 kJ mol−1 was 46.6 % of the activation energy 251 kJ mol−1 for the lattice diffusion of nickel in Type 316 austenitic steel.