A THERMODYNAMIC EVALUATION OF NITROCARBURIZING ATMOSPHERES

Knowledge of the thermodynamics of ammonia reforming in complex gases should be valuable for the control of nitrocarburizing processes. In t his papersome gas mixtures based on N + H + O and/or N + H + O + C sys tems are discussed. From the equilibrium behaviour of these gas mixtur es the nitrogen potential can be derived. The relations relevant to th e application of measurement with oxygen sensors are shown and some er rors due to the use of published equations are indicated. The calculat ion of the gas chemistry was made by a mathematical model named GPRO, developed by the authors, together-with a specially determined data ba se for complex gaseous atmospheres.