Gas carbonitriding ferrous components - by controlling amount of gas components to obtain required nitriding and carburising characteristic values

摘要

Method of gas carbonting ferrous components at 700-1000 deg. C using a mixt. of NH3, N2, H2, CO plus other C and O carrying components in which the required nitriding (r) and carburising (s) characteristic values for a predetermined surface layer composition and threatment temperature are determined from concentration diagrames and the required gas mixture compositions are determined with the added condition that an excess of decomposed NH3 is incluidng. Any deviations from the optimum value are corrected by changing the amount of O and C carrying components and altering the extent of NH3 decomposition. ADVANTAGE - Is reproducible means of altering the hardness, corrosion and wear-resistance fo the surface.