Low-carbon advanced nanostructured steels : Microstructure, mechanical properties, and applications

新型低碳納米鋼 : 微觀組織、機械性能與應用

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Pages (from-to)1580-1597
Journal / PublicationScience China Materials
Volume64
Issue number7
Online published17 Mar 2021
Publication statusPublished - Jul 2021

Abstract

Low-carbon advanced nanostructured steels have been developed for various structural engineering applications, including bridges, automobiles, and other strength-critical applications such as the reactor pressure vessels in nuclear power stations. The mechanical performances and applications of these steels are strongly dependent on their microstructural features. By controlling the size, number density, distribution, and types of precipitates, it is possible to produce nanostructured steels with a tensile strength reaching as high as 2 GPa while keeping a decent tensile elongation above 10% and a reduction of area as high as 40%. Besides, through a careful control of strength contributions from multiple strengthening mechanisms, the nanostructured steels with superior strengths and low-temperature impact toughness can be obtained by avoiding the temper embrittlement regime. With appropriate Mn additions, these nanostructured steels can achieve a triple enhancement in ductility (total tensile elongation, TE of ~30%) at no expense of strengths (yield strength, YS of ~1100 to 1300 MPa, ultimate tensile strength, UTS of ~1300 to 1400 MPa). More importantly, these steels demonstrate good fabricability and weldability. In this paper, the microstructure-property relationships of these advanced nanostructured steels are comprehensively reviewed. In addition, the current limitations and future development of these nanostructured steels are carefully discussed and outlined.
新型低碳納米鋼已被開發且廣泛應用於各種結構工程, 包括橋樑、汽車和其他重要高強度應用, 如核電站反應堆壓力容器. 納米鋼的機械性能與應用, 在很大程度上取決於其微觀組織. 通過控制析出物的大小、數量密度、分佈和類型, 可以生產出抗拉強度高達2 GPa的納米鋼, 同時保持10%以上的良好拉伸延伸率及40% 的面積縮小率. 此外, 通過調控各種強化機制, 納米鋼可以避免回火脆性, 從而具有優異的強度和低溫衝擊韌性. 通過添加適當的錳 (Mn), 納米鋼可以在不犧牲其強度下(屈服強度, YS為~1100–1300 MPa; 極限抗拉強度, UTS為~1300–1400 MPa), 延展性提高3 倍(總拉伸延伸率, TE約為30%). 更重要的是, 這些納米鋼有良好的可加工性和可焊性. 本文全面綜述了先進納米鋼的微觀結構及其性能關係. 此外, 本文對納米鋼的當前局限和未來發展進行了詳細的探討和概述.

Research Area(s)

  • heterogeneous, nano-precipitates, strength-ductility paradox, embrittlement, dislocation interactions