Achieving superior low-temperature toughness in high-strength low-carbon steel via controlling lath boundary segregation

Xinghao Wei; Lixin Sun; Zhongwu Zhang; Yang Zhang; Junhua Luan; Zengbao Jiao; Chain Tsuan Liu; Gang Zhao

Journal of Materials Research and Technology (May 2023)

Achieving superior low-temperature toughness in high-strength low-carbon steel via controlling lath boundary segregation

Xinghao Wei,
Lixin Sun,
Zhongwu Zhang,
Yang Zhang,
Junhua Luan,
Zengbao Jiao,
Chain Tsuan Liu,
Gang Zhao

Affiliations

Xinghao Wei: Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
Lixin Sun: Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China; Corresponding author.
Zhongwu Zhang: Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China; State Key Laboratory of Metal Material for Marine Equipment and Application, Iron & Steel Research Institute of Ansteel Group Corporation, Anshan 114009, Liaoning, China; Corresponding author. Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, China.
Yang Zhang: Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
Junhua Luan: Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, China
Zengbao Jiao: Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Kong, China
Chain Tsuan Liu: Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, China
Gang Zhao: State Key Laboratory of Metal Material for Marine Equipment and Application, Iron & Steel Research Institute of Ansteel Group Corporation, Anshan 114009, Liaoning, China

Journal volume & issue: Vol. 24
pp. 1524 – 1536

Abstract

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The optimal aging temperatures of 400–550 °C for high strength steels falls into the dangerous temperature range of temper-embrittlement. To obtain a good low-temperature toughness, temperatures above 600 °C are usually selected for aging treatments, resulting in a huge loss of strength. In this work, the effects of aging treatments at 500 and 550 °C on the impact performance of a Cu precipitation-strengthened steel at a low temperature of −80 °C were systematically investigated. The solute segregation at lath boundaries is found to be the main factor controlling the low-temperature toughness. Excellent impact performance of ∼180 J at −80 °C along with a high yield strength of ∼1050 MPa and a total elongation of 19% can be obtained by controlling the segregation of solute elements, specifically Mo and Mn at the lath boundaries. The evolutions of matrix and precipitates during aging treatments were investigated. The strengthening and toughening mechanisms are also critically discussed.

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/

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