Gas-handling components for high-pressure gaseous hydrogen (such as in the fuel system of fuel cell electric vehicles) are manufactured almost exclusively from austenitic stainless steels. Relatively few studies, however, have evaluated the fatigue life of this class of steels in hydrogen environments, especially at low temperature. Low temperature is important for two reasons: (1) austenitic stainless steels show an apparent minimum in tensile ductility at temperature near 220K when exposed to hydrogen environments; and (2) the service temperature range for the automotive industry is generally consider to be 233K to 358K (-40°C to +85°C). While the temperature of maximum hydrogen embrittlement from tensile tests is very near the minimum of the service temperature range, it remains unclear if the same trend applies to fatigue life properties. In this paper, we evaluate the effect of hydrogen on fatigue life of strain-hardened Type 316L. The tested alloy features a relatively high nickel content of 12 wt% and high yield strength of 590 MPa. Additionally, reduction of cost and weight of hydrogen-handling components is necessary to enhance the competitiveness of fuel cell vehicle technologies. Cost reductions can be achieved by considering alloys with lower nickel content, while higher strength materials enable lower weight. Simple estimates of cost and weight reductions that can be realized are discussed.
展开▼
