Work

The superior low temperature toughness in a low-carbon microalloyed Q500 steel by finish rolling in dual-phase region

Year: 2025

Type: article

Abstract: The superior low-temperature toughness in the low-carbon microalloed Q500 steel is obtained by finish rolling in the dual-phase (Austenite + Ferrite, A+F) region without sacrificing the yield strength. In comparison with Steel Ⅰ finish-rolled in the austenite non-recrystallization region (ANR region), the impact energy at -60 °C of Steel Ⅱ has been improved by 174 J, reaching 226 J and the yield strength has also been enhanced by 63 MPa. By visualization and quantification of crystallographic structures, the differences of low-temperature toughness can be ascribed to different variant selection mechanisms and uniformly dispersed M-A constituents. The weakening of variant selection occurs in Steel Ⅱ finish-rolled in the A+F region. More high-angle packet boundaries contributing to high toughness can be obtained, especially the boundaries of V1/V10 (&V14) and V1/V18 (&V22). Then again, the large density of high-angle grain boundaries (HAGBs) can serve as high-speed channels for carbon diffusion. Therefore, M-A constituents are dispersedly distributed within the ferrite with small size, which are also beneficial to enhance the low-temperature toughness.

Source: Journal of Materials Research and Technology

DOI: 10.1016/j.jmrt.2025.12.247

Authors: Wang Kang, Weiyi Gong, Jinshan He, Xitao Wang

Institutions: University of Science and Technology Beijing, University of Chinese Academy of Sciences, Qilu University of Technology, Key Laboratory for High Strength Lightweight Metallic Materials of Shandong Province, Shandong Academy of Sciences

Language: English

Topic: Microstructure and Mechanical Properties of Steels

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,640

Funders: National University's Basic Research Foundation of China, Center for Autonomous Systems and Technologies, National Key Research and Development Program of China, Fundamental Research Funds for the Central Universities