Session: MF-02-02 Materials for Hydrogen Service (Joint with C&S): Hydrogen-Assisted Fatigue

Paper Number: 81492

81492 - Strain-Life Performance in Hydrogen of a Dot Pressure Vessel Steel 

The drive for less expensive and lighter weight pressure vessels tends towards a desire for higher strength steels.  This directly conflicts with the trend of higher strength steels having a higher susceptibility to hydrogen embrittlement.  This conflict has had a detrimental effect on the development of newer steels for hydrogen gas pressure vessel service, though recent studies have suggested that there may be reason to hope that different microstructures could defy this high-strength trend.  Steels for hydrogen service are evaluated through the ISO 11114-4 standard.  A downside of this standard is that there are three acceptable test methods, but it is not simple to relate results from one test to another.  This comparison might be feasible with an understanding of the damage accumulated in air and in hydrogen, such as that derived from strain-life testing.  Compared to other mechanical testing methods, strain-life testing is uniquely suited to probing the plastic-dominated damage regime.  It is in this regime that hydrogen is thought to have the greatest influence.  Strain-life testing of a 4130 pressure vessel steel was conducted in air and in a high-pressure gaseous-hydrogen environment.  Analysis of the data gives insight into the various influences of hydrogen on the deformation of the steel and the effects of hydrogen on the lifetime of the pressure vessel.

Presenting Author: May Martin National Institute of Standards and Technology

Presenting Author Biography: May L Martin is a Materials Research Engineer at the National Institute of Standards and Technology (NIST) in Boulder, United States. She received her B.S. degree in Materials Science and Engineering from Cornell University in 2005, and completed her Ph.D. at the University of Illinois at Urbana Champaign in 2013. From 2014 to 2016, she was an Alexander von Humboldt post-doctoral research fellow at the Georg August University of Göttingen, Germany. Her research focuses on understanding the fracture processes of metals, especially under conditions of environmental degradation such as hydrogen embrittlement.

Authors:

May Martin National Institute of Standards and Technology
Peter Bradley National Institute of Standards and Technology
Damian Lauria National Institute of Standards and Technology
Robert Amaro Advanced Materials Testing & Technologies
Matthew Connolly National Institute of Standards and Technology
Andrew Slifka National Institute of Standards and Technology