Review: Hydrogen Embrittlement of Metals and Alloys in Combustion Engine

Abstract

In order to address the oil dependency and depletion challenges,  environmental impact of its usage and the current increasing transportation costs, an application of hydrogen enrichment of internal combustion engines (ICE) technique in vehicles is proposed. As a first step, a review is presented to study the hydrogen degradation effect on common materials that are used  to build engines. This review will support a feasibility analysis to determine if automobile engine materials have the potential to use hydrogen enriched fuels.

The most relevant reviewed topics included in this article are: i) description of the currently used materials in combustion engine  manufacturing; ii) new materials applied to hydrogen enriched engines; iii) hydrogen embrittlement mechanisms and classification; iv) embrittlement accelerating factors; and v) case studies involving hydrogen embrittlement.

It was found that specific conditions, such as pressure, temperature, material  composition and hydrogen purity determine the ideal material to be used in a hydrogen enriched environment. Some of the reviewed researches propose the usage of high purity aluminum or titanium steel alloys, materials that could be applied in ICE manufacturing to withstand hydrogen embrittlement.