Session: MF-02-01 Materials for hydrogen service I (Joint with C&S)

Paper Number: 62436

Start Time: Tuesday, July 13, 2021, 09:00 AM

62436 - Effect of Hydrogen on Tensile Properties of 304L Stainless Steel at Cryogenic Temperatures 

Safe and efficient hydrogen storage and distribution are key barriers to realizing hydrogen as an alternative energy carrier. To this end, cryogenic liquid and cryo-compressed gaseous hydrogen are considered high energy density alternatives to ambient temperature gas. However, these alternatives have significant material demands to overcome extreme temperature (20 K) and pressure (700 bar) as well as hydrogen effects. Austenitic stainless steels are widely used for cryogenic pressure vessels owing to relatively high ductility even at 4 K. However, the influence of hydrogen on mechanical properties at cryogenic temperatures has rarely been studied. In this study, the tensile properties of 304L austenitic stainless steel with internal hydrogen were evaluated at -253°C, -196°C, and -160°C. Test specimens were saturated with internal hydrogen to concentration of 140 wtppm in a high pressure environment at elevated temperature, a process called thermal precharging. While reduced temperature increased strength properties and reduced elongation at break, the presence of hydrogen increased both strength and elongation at break, but reduced ductility. Magnetic evaluation of the uniformly strained region of the test specimens suggest that hydrogen mitigates the strain-induced transformation to α’-martensite. Brittle fracture features and secondary cracking indicative of hydrogen embrittlement were observed on the fracture surfaces of hydrogen-precharged specimens, which is consistent with the loss of ductility.

Presenting Author: Daniel Merkel Pacific Northwest National Laboratory

Authors:

Daniel Merkel Pacific Northwest National Laboratory
Ethan Nickerson Pacific Northwest National Laboratory
Robert Seffens Pacific Northwest National Laboratory
Kevin Simmons Pacific Northwest National Laboratory
Chris San Marchi Sandia National Laboratories
Brian Kagay Sandia National Laboratories
Joseph Ronevich Sandia National Laboratories