Surface hardness increasing of iron alloys by nitrogen-deuterium ion implanting

In situ x-ray photoemission spectroscopy is used to study the deuterium and hydrogen oxygen etching effect in nitrogen-implanted iron alloys. A suitable deuterium-nitrogen mixture can increase the surface original steel hardness up to ∼40%. In similar conditions, hydrogen-nitrogen mixtures improves the hardness by ∼10%. On deuteration, the main change is the reduction of the zero-point energy of the hydrides bond. Due to this, the lower scission energy of hydrogen-metal bonds as compared with deuterium-metal bonds determines the favorable effect of deuterium on the nitriding process.