Coupling effect of post-weld heat treatment and fatigue damage on the hydrogen embrittlement of X80 steel welded joints

Autor: Zhiwei Gao, Shipin Wu, Ting Xiang, Baoming Gong, Caiyan Deng
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Journal of Materials Research and Technology, Vol 31, Iss , Pp 2646-2657 (2024)
Druh dokumentu: article
ISSN: 2238-7854
DOI: 10.1016/j.jmrt.2024.07.025
Popis: The influence of post-weld heat treatment (PWHT) and fatigue damage on the hydrogen embrittlement sensitivity of X80 steel welded joints, obtained using flux-cored arc welding method, was investigated in the study. Compared to the as-welded specimens, the sensitivity of hydrogen embrittlement after PWHT was decreased. However, the coupling effect of PWHT and fatigue damage improved significantly the HE sensitivity. Furthermore, the fracture site of the PWHT + pre-fatigue specimens with hydrogen-charged was transferred to the weld metal, and the fracture was characterized by intergranular fracture, quasi-cleavage (QC) and shallow dimples ductile fracture. The increase of the hydrogen content might be attributed to the evolutions of dislocation and the proportion of high-angle grain boundary caused by fatigue damage. Meanwhile, the size of QC for the hydrogen-charged welded joints was related to the degree of fatigue damage, hydrogen content and microstructure strength.
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