Interaction between dislocations, precipitates and hydrogen atoms in a 2000 MPa grade hot-stamped steel

Weijian Chen; Weiyan Zhao; Pengfei Gao; Feng Li; Shuang Kuang; Yu Zou; Zhengzhi Zhao

Journal of Materials Research and Technology (May 2022)

Interaction between dislocations, precipitates and hydrogen atoms in a 2000 MPa grade hot-stamped steel

Weijian Chen,
Weiyan Zhao,
Pengfei Gao,
Feng Li,
Shuang Kuang,
Yu Zou,
Zhengzhi Zhao

Affiliations

Weijian Chen: Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, China; Beijing Laboratory for Modern Transportation Advanced Metal Materials and Processing Technology, University of Science and Technology Beijing, Beijing 100083, China; Department of Materials Science and Engineering, University of Toronto, 184 College St, Toronto ON M5S 3E4, Canada
Weiyan Zhao: Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, China; Beijing Laboratory for Modern Transportation Advanced Metal Materials and Processing Technology, University of Science and Technology Beijing, Beijing 100083, China
Pengfei Gao: Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, China; Beijing Laboratory for Modern Transportation Advanced Metal Materials and Processing Technology, University of Science and Technology Beijing, Beijing 100083, China
Feng Li: Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, China; Beijing Laboratory for Modern Transportation Advanced Metal Materials and Processing Technology, University of Science and Technology Beijing, Beijing 100083, China
Shuang Kuang: Tangsteel, Hebei Iron and Steel Group, Tangshan 063016, Hebei, China
Yu Zou: Department of Materials Science and Engineering, University of Toronto, 184 College St, Toronto ON M5S 3E4, Canada
Zhengzhi Zhao: Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083, China; Beijing Laboratory for Modern Transportation Advanced Metal Materials and Processing Technology, University of Science and Technology Beijing, Beijing 100083, China; Corresponding author.

Journal volume & issue: Vol. 18
pp. 4353 – 4366

Abstract

Read online

Inhibiting the diffusion and aggregation of hydrogen atoms can effectively improve the resistance to hydrogen embrittlement (HE) of high strength hot-stamped steel. Here we investigate the interaction between dislocations, precipitates and hydrogen atoms in a 2000 MPa grade hot-stamped steel through a combination of microstructure characterization and HE sensitivity tests. Results show that HE susceptibility indexes increase with the increase of hydrogen charging current density, and the corresponding HE mechanism transfers from hydrogen-enhanced localized plasticity (HELP) dominates to hydrogen-enhanced decohesion (HEDE) dominates. Additionally, dislocations as reversible hydrogen traps with an activation energy of 36.3 kJ/mol, and through calculation, dislocations can carry hydrogen atoms to move. Moreover, we find that dispersed V-rich (Ti, V)C precipitates can refine grain to increase the number of reversible hydrogen traps, pin dislocations to inhibit H–dislocation interaction, and act as irreversible hydrogen traps to capture hydrogen atoms and, consequently, raise the resistance to HE.

Published in Journal of Materials Research and Technology

ISSN: 2238-7854 (Print); 2214-0697 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.journals.elsevier.com/journal-of-materials-research-and-technology/

About the journal

Abstract

Keywords