INFLUENCE OF THE STEAM AND OXYGEN FLOW RATE ON THE REACTION OF ZIRCONIUM STEAM/NITROGEN AND OXYGEN/NITROGEN ATMOSPHERES

摘要

In order to contribute to the understanding how nitrogen influences the oxidation behavior of zirconium alloys in air or steam a model is developed by quantifying steam and oxygen starvation and describing its effect on the transition between parabolic to a more linear kinetics and on the reaction rate. The model is qualitatively validated by very new separate effect tests conducted at KIT. The experiments were performed at 850 and 1100°C in steam-nitrogen mixture and in air. The total gas flow was varied at constant oxygen or steam partial pressure and the oxygen partial pressure was varied at constant oxygen or steam flow, respectively.