%0 Journal Article
%T Evaluation of susceptibility of high strength steels to hydrogen delayed cracking
%A B. £¿wieczko-£¿urek
%A S. Sobieszczyk
%A J. £¿wiek
%A A. Zieli¨½ski
%J Journal of Achievements in Materials and Manufacturing Engineering
%D 2006
%I World Academy of Materials and Manufacturing Engineering
%X Purpose: Purpose of this paper is evaluation of susceptibility of high-strength structural steels to hydrogendelayed cracking.Design/methodology/approach: Susceptibility to hydrogen delayed cracking of high-strength alloy steels havebeen made under constant load in hydrogen generating environments. Test were carried out using round notchedspecimens subjected to axial tensile load being equivalence to 75-96% of maximum force obtained from atensile tests in air. Two constructional middle carbon steel ¨C grades 26H2MF and 34HNM were tested in used(worn out) mineral engine oil at temperature of 80¡ãC. One low carbon weldable steel grade ¨C 14HNMBCu wasinvestigated in sea-water under cathodic polarization at room temperature. Presence or lack of cracking within200 hours was chosen as a measure of susceptibility to hydrogen delayed cracking. Fracture modes of failedsamples were examined with the use of scanning electron microscope.Findings: All tested steels reveal high resistance to hydrogen degradation under constant load. Hydrogendelayed cracking does not occur until the load level is as high as flow stress (yield strength).Research limitations/implications: Further research should be taken to reveal the exact mechanism of crackinitiation.Practical implications: Tested steels could be safely utilized within elastic range of stress in hydrogengenerating environments.Originality/value: Under the critical load and hydrogen concentration notched samples premature failed andhydrogen-enhanced localised plasticity (HELP) model is a viable degradation mechanism.
%K Crack resistance
%K High-strength steels
%K Hydrogen embrittlement
%K Hydrogen delayed cracking
%U http://www.journalamme.org/papers_amme06/1116.pdf