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empirical method to estimate hydrogen embrittlement of metals as a function of hydrogen gas pressure at constant temperatureHigh pressure Hydrogen (H) gas has been known to have a deleterious effect on the mechanical properties of certain metals, particularly, the notched tensile strength, fracture toughness and ductility. The ratio of these properties in Hydrogen as compared to Helium or Air is called the Hydrogen Environment Embrittlement (HEE) Index, which is a useful method to classify the severity of H embrittlement and to aid in the material screening and selection for safety usage H gas environment. A comprehensive world-wide database compilation, in the past 50 years, has shown that the HEE index is mostly collected at two conveniently high H pressure points of 5 ksi and 10 ksi near room temperature. Since H embrittlement is directly related to pressure, the lack of HEE index at other pressure points has posed a technical problem for the designers to select appropriate materials at a specific H pressure for various applications in aerospace, alternate and renewable energy sectors for an emerging hydrogen economy. Based on the Power-Law mathematical relationship, an empirical method to accurately predict the HEE index, as a function of H pressure at constant temperature, is presented with a brief review on Sievert's law for gas-metal absorption.
Document ID
20100009828
Document Type
Conference Paper
Authors
Lee, Jonathan A.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 25, 2013
Publication Date
February 21, 2010
Subject Category
Metals and Metallic Materials
Report/Patent Number
M10-0268
Meeting Information
Materials Challenges in Alternative and Renewable Energy 2010 Conference(Cocoa Beach, FL)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.