Review of Characterization on Hydrogen Embrittlement by Micro-Sample Testing Methods

Abstract

Conventional-sized specimens have been well and widely applied in research on hydrogen embrittlement. However, when the limited-size core components (nozzles and valves, etc.) of hydrogen energy equipment are evaluated for service damage, traditional testing with conventional-sized samples is no longer applicable and micro-sample testing methods are required. In this paper, recent progress in the characterization of hydrogen embrittlement achieved via a small-sized sample tensile test, small punch test and nanoindentation test is reviewed. The commonly used geometries and dimensions of various small-sized specimens are first described and the in situ hydrogen-containing environment testing cases equipped with small-sized specimens are presented, proving the advantages of direct observations of hydrogen influences on the mechanical property and microstructure evolution. Then, the quantitative analysis of hydrogen embrittlement sensitivity involving a small punch test is discussed, with a focus on the comparisons of the hydrogen embrittlement index calculated using different definition methods. Finally, the nanoindentation test of investigation on the interaction between hydrogen and dislocation in metals and the effect of indentation strain rate are summarized. Furthermore, the specific research directions and applications of micro-size specimens for further investigation on hydrogen embrittlement are identified.

Effect of Hydrogen Charging on the Mechanical Properties of High-Strength Copper-Base Alloys, Austenitic Stainless Steel AISI 321, Inconel 625 and Ferritic Steel 1.4511

“…Damage might emerge during manufacturing or as delayed fracture when a hydrogen-containing component is put under operating stresses. Hydrogen Environmental Embrittlement (HEE) is the most common form of HE [8,9,[13][14][15]. Hydrogen is either generated due to contact with aqueous solutions as a product of corrosion processes (cathodic stress corrosion cracking) or by a gaseous atmosphere such as pressurized hydrogen.…”

Effect of Hydrogen Pressure and Punch Velocity on the Hydrogen Embrittlement Susceptibility of Pipeline Steels Using Small Punch Tests under Gaseous Hydrogen Environments at Room Temperature

“…Recently, Garcia et al investigated the effects of strain rate and hydrogen contents on HE for pipeline steel of API X65 steel through SP tests with the online hydrogen pre-charging technique [23,24]. Tao et al also reviewed HE characterization using microsample testing [25]. In this review, the HE sensitivity achieved through small sample tensile testing, SP testing, and nanoindentation testing is quantitatively analyzed and discussed.…”