Understanding and mitigating hydrogen embrittlement of steels: a review of experimental, modelling and design progress from atomistic to continuum

Abstract

Hydrogen embrittlement is a complex phenomenon, involving several lengthand timescales, that affects a large class of metals. It can significantly reduce the ductility and load-bearing capacity and cause cracking and catastrophic brittle failures at stresses below the yield stress of susceptible materials. Despite a large research effort in attempting to understand the mechanisms of failure and in developing potential mitigating solutions, hydrogen embrittlement mechanisms are still not completely understood. There are controversial opinions in the literature regarding the underlying mechanisms and related experimental evidence supporting each of these theories. The aim of this paper is to provide a detailed review up to the current state of the art on the effect of hydrogen on the degradation of metals, with a particular focus on steels. Here, we describe the effect of hydrogen in steels from the atomistic to the continuum scale by reporting theoretical evidence supported by quantum calculation and modern experimental characterisation methods, macroscopic effects that influence the mechanical properties of steels and established damaging mechanisms for the embrittlement of steels. Furthermore, we give an insight into current approaches and new mitigation strategies used to design new steels resistant to hydrogen embrittlement.

A Modified Electrochemical Nanoindentation Setup for Probing Hydrogen-Material Interaction Demonstrated on a Nickel-Based Alloy

“…Despite some contradictions, overlaps are possible. 11,12 Therefore, it is important to find new promising techniques, both experimentally and simulated, to investigate and understand the acting mechanisms in further detail. A promising experimental approach, which was first proposed by Barnoush and Vehoff 13 in 2006, is electrochemical nanoindentation (ECNI).…”

Effect of Storage Conditions of Rutile Flux Cored Welding Wires on Properties of Welds

“…during welding, is a highly degrading. It is important to control the diffusible hydrogen amount within the microstructure in order to ensure its resistance to embrittlement [25,26]. In the case of welding, one of the basic ways to implement such control is to assess the state of welding consumables and their impact on the level of diffusible hydrogen.…”

Hydrogen Accumulation and Distribution in Pipeline Steel in Intensified Corrosion Conditions

“…With the increase in the hydrogen amount by hundreds of times, its molecularization occurs, thereby creating the local pressure greater than 100 atmospheres [14,15,16]. Moreover, when hydrogen reacts with some of alloying elements, it forms hydrides that bring these elements out of the functional state of substitutional or interstitial solutions [14,15,16].…”

“…With the increase in the hydrogen amount by hundreds of times, its molecularization occurs, thereby creating the local pressure greater than 100 atmospheres [14,15,16]. Moreover, when hydrogen reacts with some of alloying elements, it forms hydrides that bring these elements out of the functional state of substitutional or interstitial solutions [14,15,16]. Hydride, carbide and hydride segregations, which form in dislocations or along the grain boundaries, lower their mobility and cohesive energy resulting in formation of coalescences with defects [14,15,16].…”

“…Moreover, when hydrogen reacts with some of alloying elements, it forms hydrides that bring these elements out of the functional state of substitutional or interstitial solutions [14,15,16]. Hydride, carbide and hydride segregations, which form in dislocations or along the grain boundaries, lower their mobility and cohesive energy resulting in formation of coalescences with defects [14,15,16]. In addition, hydrogen causes reduction in the material hardness changing, the surface energy during the simple interpolation, i.e., the Rehbinder effect [17].…”