Issue |
Metall. Res. Technol.
Volume 118, Number 2, 2021
|
|
---|---|---|
Article Number | 212 | |
Number of page(s) | 11 | |
DOI | https://doi.org/10.1051/metal/2021009 | |
Published online | 25 March 2021 |
Regular Article
The critical influence of La content on the microstructure-toughness relationship in the simulated coarse-grained heat-affected zone of high-strength low-alloy steels
1
The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology,
Wuhan
430081, PR China
2
School of Mechanical and Electrical Engineering, Foshan Polytechnic,
Foshan
528237, PR China
3
Band (Foshan) Metallic Composite Materials Co. Ltd.,
Foshan
528000,
Guangdong, PR China
* e-mail: wanxiangliang@wust.edu.cn
** e-mail: liguangqiang@wust.edu.cn
Received:
14
September
2020
Accepted:
10
February
2021
The present study was envisaged to investigate the role of La content on the particle, microstructure and toughness in the simulated coarse-grained heat-affected zone (CGHAZ) of high-strength low-alloy steels. Three steels with La content of 0.016 wt.%, 0.046 wt.% and 0.093 wt.% were prepared and simulated in a 100 kJ/cm heat input welding thermal cycle. Subsequently, the particle and microstructure of selected specimens were characterized and the impact absorb energy was measured at −20 °C. The results indicated that the La2O2S inclusions in 0.016 wt.%-La steel were gradually modified to LaS-LaP in 0.046 wt.%-La steel and to LaP in 0.093 wt.%-La steel. A higher fraction of acicular ferrite was obtained in the simulated CGHAZ of 0.016 wt.%-La steel, since the inclusion of La2O2S was more powerful to induce the formation of acicular ferrite. Furthermore, the fraction of M-A constituents in the simulated CGHAZ increased with increasing La content. The impact toughness in the simulated CGHAZ of 0.016 wt.%-La steel was the highest, owing to the high fraction of the fine-grained acicular ferrite and low fraction of M-A constituent.
Key words: HSLA steels / lanthanum / microstructure / grain refinement / impact toughness
© EDP Sciences, 2021
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.