Delamination toughening in a low carbon microalloyed steel plate rolled in the dual-phase region

Delamination toughening in a low carbon microalloyed steel plate rolled in the dual-phase region

Shen, X. J. (Northeastern University China)
Li, D. Z. (Northeastern University China)
Tang, S. (Northeastern University China)
Chen, J. (Northeastern University China)
Fang, H. (TU Delft RST/Fundamental Aspects of Materials and Energy; TU Delft Novel Aerospace Materials)
Wang, G. D. (Northeastern University China)

2019-10-24

It is still a big challenge to obtain excellent low-temperature toughness for bulk steel materials. Delamination is an effective method to improve low-temperature toughness. In the present study, delamination toughening in a low carbon microalloyed steel plate with elongated and ultrafine-grained microstructure rolled in the dual-phase region has been investigated in detail. When toughness was measured along normal direction, the steel plate had a high upper shelf energy and no delamination occurred in the upper shelf region. A large delaminated crack parallel to rolling plane started to appear and changed the propagation path of main crack when testing temperature was lower than −60 °C. We find this kind of delamination induces a second upper shelf in the Charpy transition–temperature curve. The second upper shelf, reaching up to 300 J in the temperature range of −60 °C to −140 °C, results in excellent low-temperature toughness for the steel plate, and the ductile-brittle transition temperature is lowered to −157 °C. The developed steel plate also has high low-temperature toughness measured along transverse direction due to delamination. The effect factors on upper shelf energy, delamination mechanism and delamination toughening are discussed.

Crystallographic texture
Delamination toughening
Elongated and ultrafine-grained microstructure
Steel plates

http://resolver.tudelft.nl/uuid:81cbbf9e-8e64-427b-840a-886bd0e2c769

https://doi.org/10.1016/j.msea.2019.138342

2020-05-06

0921-5093

Materials Science and Engineering A: Structural Materials: Properties, Microstructures and Processing, 766

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

journal article

© 2019 X. J. Shen, D. Z. Li, S. Tang, J. Chen, H. Fang, G. D. Wang