1984

Pulkkinen, Raimo

The current knowledge of the mechanisms of gas nitriding bcc iron alloys was surveyed.Alloys studied in the experimental work were unalloyed and chromium-, molybdenum- and silicon-alloyed -irons.The effects of the surface phases and alloying elements on the kinetics of nitrogenation of -iron were presented.The reasons for the formation of surface iron nitrides under apparently thermodynamically unfeasible conditions were explained.The effect of alloying elements on the distribution of the nitride formation at the iron surface and the effect of alloying elements of grain boundary segregation in bright nitrided -irons were studied.Also the effect of chromium, molybdenum and silicon as alloying elements on the activity coefficient of nitrogen in -iron was presented.