| 摘要 |
A process for improving the wear and corrosion resistance of ferrous metal parts consists in immersing the parts, which have previously been treated using a nitriding, diffusion technique, in a molten salt bath comprising carbonates, nitrates, hydroxides and oxygenated alkali metal salts. The relative anionic proportions by weight of carbonates, nitrates and hydroxides expressed in terms of their sodium salts and corresponding to the active phase, that is the liquid in the bath, are as follows: 11<CO32-<23 19<NO3-<37 6<OH-<19 and the proportion by weight of oxygenated alkali metal salts, expressed in equivalents of Cr2O72- is as follows: 0.05<oxygenated anions<0.41. This process guarantees a high degree of reproducibility of results regardless of the type of treated part.
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