Oxidation of Series of Dilute Zr Alloys at 500 C in Water Vapor Atmosphere Containing Trace Amounts of Oxygen

A flow type reaction system was used to study the water vapor reaction of a series of dilute zirconium alloys at 500 C (932 F). These alloys included Zircaloy 2, Zircaloy 4, the eutectoids (w/o) Zr-1.0 Cr, Zr-1.3 Ni and Zr-5.0 V. Pure zirconium was included for comparison. Both hydrogen and oxygen uptakes were measured for times up to 237 hours. Hydrogen uptake curves show small amounts of hydrogen were picked up for weight gains below 1000μg/cm². Above this weight gain the hydrogen uptakes were 25-30 percent of theoretical. A model was proposed for the reaction.