EFFECT OF PRIOR OXIDATION ON BRIEF NITRIDING PROCESSES

It is well known that prior oxidation affects chemothermal-treatment p rocesses. For example, the presence of thin oxide films obtained durin g brief oxidation accelerates cementation and nitrocementation at high temperatures. Prior oxidation at 450-550-degrees-C for long times (lo nger than 0.5 h) exerts a retarding influence on the formation of an a nisotropic layer. In this connection, it is interesting to determine t he effect of prior brief oxidation (5-30 min) on the formation of nitr ided layers.