Influence of temperature on nitrogen-implanted steels and iron

The results of annealing steels and iron in air and under vacuum are compared with results of implantation experiments on the same materials at various temperatures. The distribution profiles of the implanted nitrogen are obtained against time using the narrow 429 keV resonance of the non-destructive 15N(p,αγ)12C nuclear reaction. Anneals under vacuum were carried out at 150, 175, 200 and 2500C. At 1500C the distribution profile narrowed although the maximal height remained almost the same. Above 2000C the removal of nitrogen occurred quite rapidly. Consequently diffusion is not the slow mechanism responsible for the evolution kinetics of the remaining nitrogen. Anneals in air indicated the influence of mild oxidation and a slowing-down of the out-diffusion. The results are compared with those obtained after implantations at various temperatures. (Auth.)