Review of the Effect of Hydrogen Gas on Fatigue Performance of Steels

Abstract

To develop hydrogen energy, it is important to understand the effects of hydrogen on mechanical properties in all applications — production, transportation, storage and fuel cells. Although a considerable amount of work has been carried out on hydrogen related embrittlement, there is comparatively less work on the effect of a hydrogen environment on fatigue performance of steels. It is essential to carry out comprehensive and coordinated research to understand how a component is affected when exposed to a hydrogen environment, how to prevent or minimise the failure probability, and finally to gather critical data to develop design guidance and government regulations to ensure safe operation of infrastructures involving hydrogen environment. The paper reviews the effect of a gaseous hydrogen environment on fatigue endurances and fatigue crack growth rates of steels, identifies the major factors promoting hydrogen effects and reviews the requirements for carrying out fatigue tests in hydrogen environment. The review covers degradation on fatigue performance of many variables including steel grades, ΔK magnitude, hydrogen partial pressure, loading frequency, gas composition, stress ratio, microstructures, base and weld metals and temperature. The mechanisms responsible for the accelerated crack growth rates in hydrogen environment and the implication of the degradation on fatigue design are also discussed. It was found that, unlike hydrogen embrittlement, fatigue performance of steels in hydrogen is degraded in both ferritic and austenitic steels, and in both low and high strength steels. The degradation by hydrogen gas is more pronounced with respect to fatigue crack growth rate than fatigue endurance of steels. Based on the results of the review, recommendations are made with respect to further research work required.