Abstract This study investigates hydrogen-assisted cold cracking (HACC) in high-strength and ultra-high-strength steel welds, a phenomenon triggered by the combined effects of a crack-susceptible microstructure, residual stresses from welding, and diffusible hydrogen. HACC can compromise structural integrity, especially when standard preventive measures are not properly applied. Existing test methods for evaluating diffusible hydrogen concentration and cracking susceptibility vary widely and often do not represent real-world welding conditions. The research aims to develop a practical, industry-oriented test method that allows simultaneous measurements of hydrogen concentration and evaluation of its mechanical properties within the same sample. Using gas metal arc welding (GMAW), samples are fabricated under parameters that simulate actual manufacturing practices. The process incorporates controlled moisture concentration of the shielding gas regulating hydrogen levels in the weld metal. Samples are then analyzed for hydrogen concentration and degradation in mechanical performance through tensile testing. The study uses the high-strength steels S690QL and S960QL, with matching filler materials, to evaluate the applicability of the proposed method. The results are compared with DIN ISO 3690 standard samples to assess the method’s reliability in identifying HACC risk. The approach provides a more realistic and transferable assessment of hydrogen-related failure in welded high-strength steels.
Miedlig et al. (Wed,) studied this question.