The stress intensities for slow crack growth in steels containing hydrogen

Hydrogen in Metals

“…The microscopic mechanism of fracture can simply be accelerated, * The relation between surface energy and cohesion has been elaborated by Rice [69]. Further discussion may be found in [70] and [71]. which appears to be the case for spheroidized steels, or can actually involve a change in mode from, for example, ductile rupture to intergranular decohesion or cleavage.…”

Hydrogen assisted cracking of AISI 4137M steel in O&G environments

“…The K th values in high strength steels decreases with increasing concentration of total hydrogen and diffusible hydrogen concentration [5,6,2,7] and the relationship is of the form:…”

The role of heat treatment and alloying elements on hydrogen uptake in Aermet 100 ultrahigh-strength steel

“…Aermet 100 ultrahigh-strength martensitic steel was developed for aerospace applications in order to replace its predecessors that suffered from stress corrosion cracking or low toughness [1][2][3][4][5]. The alloy is used in landing gears, jet engine shafts and structural components.…”

“…Aermet 100 combines high strength, high hardness and fracture toughness with good ductility [1]. High-strength steels in general are prone to degradation by hydrogen (H), thereby losing their excellent mechanical properties [2,3,5]. The presence of atomic hydrogen near a crack tip is recognized to cause crack propagation at stresses far below the critical stress in a hydrogen free condition [6].…”