Positive effects of hydrogen in metals

Hydrogen is often present in metals as a result of production, fabrication and processing operations or service conditions. Thus, it can be regarded as an alloying element. Although, high hydrogen levels in metals can have a devastating effect on the mechanical properties, many positive effects can also be derived from its high solubility. The objective of this paper is to review some positive effects of hydrogen in metals. An emphasis will be made on enhancements in the processing properties due to hydrogen (thermohydrogen processing (THP)), though other uses of hydrogen, such as an energy storage device and in the electronics industry will also be presented.