Assessment of the hydrogen interaction on the mechanical integrity of a welded martensitic steel

Abstract

This work evaluates the effect of hydrogen on the mechanical integrity of a weld in a martensitic base metal. Different regions in the heat-affected zone (HAZ) are reproduced to investigate the interaction of the local microstructure with hydrogen. The hardness strongly depends on the distance from the welding joint due to the different phases present. The HAZ contains zones of acicular ferrite, coarse martensite and tempered martensite. Additionally, the entire weld is subjected to a constant load while being simultaneously electrochemically charged with hydrogen. During this test, a crack initiates in the filler, showing the highest hydrogen solubility as demonstrated by thermal desorption spectroscopy, while propagation occurs along the microstructure of the HAZ with the highest hardness level.

KEYWORDS:

• Welding
• hydrogen-induced cracking
• martensitic steel
• thermal desorption spectroscopy
• constant load tensile testing

Acknowledgements

The authors would like to thank the Belgian Welding Institute (BWI/BIL/IBS) for providing the material and the weld, as well as performing the heat treatments for the welding simulations. TD holds a postdoctoral fellowship via the Research Foundation – Flanders (FWO, grant 12ZO420N). The authors also wish to thank the Special Research Fund (BOF), UGent (BOF15/BAS/062 and BOF01P03516). The authors also acknowledge the technicians and staff working at the Department Materials, Textiles and Chemical Engineering, UGent, for their help with the experiments and/or sample preparation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.

Additional information

Funding

This work was supported by Bijzonder Onderzoeksfonds [grant number BOF15/BAS/062; BOF01P03516; BOF24J069-17]; Fonds Wetenschappelijk Onderzoek [grant number 12ZO420N].