Comparison of Stainless Steels for High-Pressure Hydrogen Service

Type 316/316L austenitic stainless steels are considered the benchmark for resistance to hydrogen embrittlement in gaseous hydrogen environments. Type 316/316L alloys are used extensively in handling systems for gaseous hydrogen, which has created engineering basis for its use. This material class, however, is relatively expensive compared to other structural metals including other austenitic stainless steels, thus the hydrogen fuel cell community seeks lower-cost alternatives. Nickel content is an important driver of cost and hydrogen-embrittlement resistance; the cost of austenitic stainless steels is largely determined by nickel content, while high nickel content generally improves resistance to hydrogen embrittlement. These circumstances create the perception that less-expensive grades of austenitic stainless steels are not appropriate for hydrogen service. While other grades of austenitic stainless steels are generally more susceptible to hydrogen embrittlement, in many cases the hydrogen-affected properties are superior to the properties of materials that are considered acceptable, such as aluminum alloys and A-286 austenitic stainless steel. In this paper, the properties of a variety of austenitic stainless steels are compared with the aim of promoting the consideration of a wider range of austenitic stainless steels to reduce cost and reduce weight of high-pressure components for hydrogen service.