The durability of alloys can be influenced significantly
by hydrogen uptake, leading to a degradation of the
mechanical properties with possible subsequent hydrogen assisted
cracking (HAC) [1,2]. In numerous investigations,
different factors affecting the hydrogen embrittlement have
been studied, e.g. hydrogen content [3], residual stress and
strain due to internal or external forces [4] and microstructure
[5]. All these factors can lead to a critical condition for
hydrogen embrittlement through specific mechanisms. The
most popular are called hydrogen-enhanced decohesion
(HEDE) and hydrogen-enhanced localized plasticity
(HELP) [6,7].
The uptake of hydrogen into the material can occur via
different ways. One way for example is the diffusion of dissociated
hydrogen from the plasma of the protection gas
during arc welding into the weld pool [8] where it remains
after solidification. Another way could be the diffusion from
the surface into the bulk due to corrosion processes [9].
However, the material’s degradation process is enhanced
drastically if hydrogen is introduced rapidly exceeding
locally the solubility limit. Then, recombination of hydrogen
may yield hydrogen-assisted formation and growth of
microvoids. Subsequently, HAC, also referred to as cold
cracking, can cause failure of the material or component,
respectively.