Review and Assessment of the Effect of Hydrogen Gas Pressure on the Embrittlement of Steels in Gaseous Hydrogen Environment

Abstract

Hydrogen gas pressure is an important test parameter when considering materials for high-pressure hydrogen applications. A large set of data on the effect of hydrogen gas pressure on mechanical properties in gaseous hydrogen experiments was reviewed. The data were analyzed by converting pressures into fugacities (f) and by fitting the data using an f|n| power law. For 95% of the data sets, |n| was smaller than 0.37, which was discussed in the context of (i) rate-limiting steps in the hydrogen reaction chain and (ii) statistical aspects. This analysis might contribute to defining the appropriate test fugacities (pressures) to qualify materials for gaseous hydrogen applications.

Effect of Hydrogen in Mixed Gases on the Mechanical Properties of Steels—Theoretical Background and Review of Test Results

“…Using this set of equations requires both b HH and b Gas for the calculation of f HH in a gas mixture according Equation (2). Within the given temperature and pressure range for most engineering applications, the co-volume constant of hydrogen can be assumed as constant (b HH = 15.84 cm 3 /mol [10]) whereas the co-volume constant of the other gas (b Gas ) can be derived from Equation (4) as a function of pressure using experimentally measured compressibility factors.…”

“…Using the data from Figure 2, the co-volume constant of the respective gas mixture b (N 2 -H 2 or CH 4 -H 2 ) can be calculated according to Equation (5), and finally the fugacity of hydrogen in a gas mixture f HH can be calculated according to Equation (2).…”

“…This effect is often referred to as 'hydrogen embrittlement'. It is further known that the deterioration of mechanical properties of steels increases with increasing hydrogen concentration inside the steel, which increases with increasing hydrogen gas pressure, more precisely hydrogen fugacity [2]. The fugacity is often described as the activity of the real gas, i.e., the gas in states that are not well described by the ideal gas law.…”

Analysis of Hydrogen Embrittlement on Aluminum Alloys for Vehicle-Mounted Hydrogen Storage Tanks: A Review

“…More and more attention has been paid to the safety of transportation equipment [1][2][3]. Facing the energy crisis, hydrogen-fueled vehicles are recognized as a most promising solution [4][5][6][7]. Compared with electric vehicles, when refueling with energy, the hydrogen vehicle has advantages of technical simplicity and high filling rates [8].…”

“…It is widely accepted that hydrogen embrittlement (HE) has become a serious problem since high-strength steel became widely used [5,7,13,14]. With the widespread application of aluminum alloys, it's found that aluminum and its alloys also have a higher hydrogen content [15][16][17].…”