 T.T.N. Veneta - Nervesa della Battaglia (TV) / VACUUM THERMAL TREATMENTS - NITRIDING - CASEHARDENING - COATINGS |
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 The steel classes are showed hereafter with the comparison of the relative characteristics like: wear resistance for applications (where there are problems of grooving or early consumption of the surfaces), problems of corrosion for all the mould processes relative to plastic materials with gas production or aggressive substances and resistance to compression to avoid that the edges may bend on themselves or may round off for high mould pressures. Tab. 1: Correspondences of wear resistance characteristics, corrosion and compression for traditional steels and powders usually undergoing vacuum tempering processes. |
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 T.T.N. Veneta installed also 5 plants of gas nitriding and oxidation with maximum dimensions of 800 X 4000 mm. They are used to perform all the different kinds of nitriding and nitro-carburizing on a wide spectrum of materials. The advantage of nitriding is that it's a diffusive treatment and takes place in a convective environment at about 500°C and causes the production of atomic nitrogen coming from the dissociation of ammonia and its consequent diffusion inside the material according to the maintenance time which varies from 5 h (0.05 mm) to 150 h (1 mm) according to the depth required. Tav2: graphic with hardening curves for different kinds of steels undergoing to cycles of gas nitriding at deep depths. The greatest advantages of nitriding as compared to thermal treatments of cementation and induction tempering are relevant to reduce deformations, cracks risks, spalling reduction and there is no need to remove the thickness after the treatment. |
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