The interaction of hydrogen with iron oxide inclusions in iron

Abstract

The interaction of hydrogen with the interface between an iron oxide inclusion and iron was studied using a thermal analysis technique with a gas chromatograph as the hydrogen detector. The amount of hydrogen evolved from the trap site was measured and its relation to the activation energy and trap binding energy was studied. The peak evolution rate which occurred at 695 K was caused by the hydrogen trapped at the interfaces of iron oxide inclusions. From the relation between the peak temperature and the heating rate the trap activation energy required to escape from the interface of an iron oxide inclusion was found to be 47.2 kJ mol −1, and the trap binding energy obtained from the relation between the peak area and the hydrogen charging temperature was found to be 15.7 kJ mol −1. The energy level of hydrogen around the trap site was estimated from the above values.