PSI - Issue 69

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ScienceDirect

Procedia Structural Integrity 69 (2025) 97–104

13th European Symposium on Martensitic Transformation 2024 (ESOMAT 2024) Effect of pearlite on microstructures and tensile properties in Mn heterogeneous steels Dezhen Yang a, b, # , Youjing Zhang a, # , HaoZhang b , Qi Chen b , Xiaohui Wang a , Zhiping Xiong b, c, * a National Key Laboratory of Marine Corrosion and Protection, Luoyang ship Material Research Institute, Luoyang 471023, China b National Key Laboratory of Science and Technology on Materials under Shock and Impact, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China c Tangshan Research Institute, Beijing Institute of Technology, Tangshan 063000, China Abstract Mn heterogeneity in high-temperature austenite is an effective way to tailor retained austenite and achieve a good balance of strength and ductility. Instead of conventional quenching and tempering, fast and short austenitization from Mn-partitioned pearlite followed by quenching and tempering is carried out, leading to the formation of ghost pearlite. Here, we have studied the role of the lamellar width of cementite on microstructures and tensile properties in Mn-heterogeneous steels. With increasing pearlite transformation temperature from 540 °C to 570 °C, the lamellar width of cementite increases from 11.4±2.1 nm to 18.3±2.8 nm, effectively enlarging the size of the Mn-enriched regions in high-temperature austenite, thereby facilitating the formation of ghost pearlite after quenching to room temperature. The high volume fraction of ghost pearlite can ensure a high strength due to refined width of martensitic lath, while high RA fraction can ensure a good ductility, leading to a simultaneous increase in yield strength and uniform elongation with increasing pearlite transformation temperature. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Guest Editors

Keywords: Mn heterogeneity; pearlite; austenite; martensite;

* Corresponding author. Tel.: +86 68913951; fax: +86 68913951. E-mail address: zpxiong@bit.edu.cn, zuileniwota@126.com. # These authors contributed equally to this work and should be considered co-first authors.

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Guest Editors 10.1016/j.prostr.2025.07.014