Mitigating hydrogen embrittlement in high-strength steels

R&D Focus Areas:
Hydrogen embrittlement, Safety and standards, Mobility

Lead Organisation:
The University of Sydney

Partners:
CITIC Metal; National Taiwan University; Shanghai Jiao Tong University

Status:
Active

Start date:
April 2019

Completion date:
November 2022

Key contacts:
Dr Yi-Sheng (Eason) Chen – yi-sheng.chen@sydney.edu.au
Professor Julie Cairney – julie.cairney@sydney.edu.au

Funding:
AUD$321,269 – Australian Research Council
AUD$100,000 – CITIC Metal
AUD$105,000 – The University of Sydney

Project total cost:
AUD$1,076,000 – combined cash and in-kind contribution

Project summary description:
High-strength steels hold enormous potential for the automotive industry, where they would provide major environmental benefits by enabling lighter and more efficient vehicles. However, this use is prevented by the fact that these steels become brittle due to the hydrogen present in automotive environments, and failure can involve considerable damage.

A possible solution is to incorporate finely dispersed precipitates to act as ‘hydrogen traps’ within the microstructure of the steel. Although empirical results show this approach to be effective in preventing the detrimental effects of hydrogen, the mechanism for hydrogen trapping remains unclear, so it is not easy to predict the response of alloys that are designed to take advantage of this mechanism. Progress has been limited by the fact that it is experimentally challenging to measuring the precise location of hydrogen atoms at the atomic scale.

This project will determine the precise mechanism of hydrogen trapping in niobium-containing high-strength steels by using a new approach, cryogenic atom probe tomography. High-resolution 3D atom maps will be obtained from deuterated samples held at cryogenic temperatures, providing precise information about the position of hydrogen atoms within the alloys. In the process, we will set up a new open access experimental capability for the direct observation of hydrogen at the atomic scale that will also be available to other Australian researchers.

Atom probe data will be combined with other advanced microscopy data, thermal desorption measurements, macroscopic mechanical testing and first-principle calculations to provide a thorough understanding of hydrogen trapping. This information will be used by our partner, CITIC Metal, to provide design guidelines for hydrogen compatible, niobium-alloyed light-weight high-strength steels.

Related publications and key links:
Yi-Sheng Chen and Julie Cairney et al. ‘Observation of hydrogen trapping at dislocations, grain boundaries, and precipitates’ Science 367 (2020) 171-175 https://doi.org/10.1126/science.aaz0122

Yi-Sheng Chen, Matthew J Griffith, and Julie M Cairney ‘Cryo atom probe: Freezing atoms in place for 3D mapping’ Nano Today 37 (2021) 101107 https://doi.org/10.1016/j.nantod.2021.101107

Higher degree studies supported:
This project supports the training for 2 PhD students and 1 Honours student and is of a length of 3 years.

 

Reviewed: January 2023