ION NITRIDING

	Morphology of the hardened layer The accurate control of nitrogen percentage in the mixture (it is possible to control it to the tenth of liter), grant us the possibility to carry out nitriding on any kind of steel, included Duplex, the precipitation hardening, high-speed steels, known to be very sensitive to brittleness due to nitrogen diffusion. These materials are treated with high temperatures in the furnace to obtain a minimum thickness (>0.05 mm) and meanwhile nitrogen percentage may be reduced to 0.5 % on hydrogen. This so-easy-to-mix blend allows, therefore, to nitride moulds for thermoplastic materials, for cold deformation, for ground and lapped equipment at finished dimensions and zero tolerance, without risking the detachment of ground surface pieces during the use or strain and swelling of the materials above the accepted limit. Furthermore the surface roughness is slightly modified and it is enough to use a cloth with diamond compound to obtain a glass surface.
	Fig.2.: Comparison of 34CrAlNi7 between ion nitrite and gas nitrite materials with he same depth. The different morphology in the hardened zone is very high and allows to understand clearly the differences between embrittlement and the reciprocal shoulder tightness.