In-situ Observation of the Environmental Resistance of Pure Iron Using Hydrogen and Oxygen Sensors in the Environment Simulating Hydrogen Combustion

The environmental resistance of pure iron was evaluated with oxygen and hydrogen sensor installed after the oxidation furnace. The amount of introduced oxygen was precisely controlled by oxygen pump-sensor at the front stage of the oxidation furnace and the reaction with hydrogen was analyzed. As a result, when oxygen was supplied, a reaction between hydrogen and oxygen occurred, but when sufficient oxygen was not supplied, a hydrogen-vapor environment was created and oxidation was not accelerated. However, when the amount of supplied oxygen was excessive, the environment became oxygen-steam environment and the oxidation was accelerated. At that time, it was clarified that the oxidation by oxygen was dominant under the oxygen-water vapor environment, and the mass gain increased. In addition, the border of the region dominated by oxygen oxidation and that by steam oxidation was clarified by precisely controlling the amount of supplied oxygen by the oxygen pump sensor.