摘要
钢铁是制造业以及结构应用的主要材料,这很大程度上是因为它们拥有良好的强度与塑性,且价格低廉。材料工程界一直在不停研究更优越的强度和塑性相结合的材料。具有纳米晶/超细晶结构的纳米钢铁材料显示出优异的力学性能,例如卓越的硬度和强度,作为高强钢应用非常有吸引力。然而,超强纳米钢铁材料通常在环境温度下具有低塑性,这极大地限制了它们的应用。由于晶粒细化方法提高强度受到塑性的限制,新的高强度水平下增强塑性的方法成为钢铁材料高性能化的研究热点。为了提高超细晶/纳米晶钢铁材料的塑性,考虑通过调整微观组织结构来提高其加工硬化能力。通过对已经报道的同时具有高强度和良好塑性的纳米结构钢铁材料的实验数据、组织结构的归纳,总结了优化纳米高强钢铁材料塑性的三种基本方法:纳米第二相、微纳复合结构和多相不均匀复合结构。这些增塑方法的主要机理是利用组织结构的改变提高超细晶金属的加工硬化能力以维持其良好的均匀塑性变形,以及利用组织相变提高金属的塑性。这些不均匀纳米结构类似于复合物,具有共同的材料设计和力学原理。本文归纳了钢铁材料常用的强化方法,综述了纳米/超细晶高强钢铁材料提高塑性的方法,尤其是通过突出介绍一些新颖的纳米结构设计来实现钢铁材料的高强高塑,总结了高强高塑纳米钢铁材料的变形机制,以期为纳米晶金属增强塑性研究提供参考。
Steels have been widely used in manufacturing industries and structural applications because of their high strength,good plasticity and low cost.A superior strength-plasticity synergy of steels has been pursued by material engineers and scientists.Nano/ultrafine-structured steels show excellent mechanical properties,such as excellent hardness and strength,which are attractive as a high-strength steel.However,ultra-high strength steels with nano/ultrafine-grained structure usually have low plasticity at ambient temperature,which restrict their wide applications in many critical areas.Because grain refining results in low ductility of steels at high strength level,it has been a hot topic to develop new means for enhancing plasticity.In order to improve the plasticity of nano/ultrafine grained steels,it is considered to improve the strain hardening ability by tailoring the microstructure.In recent years,many nanostructured steels with high strength and good plasticity have been reported.By summarizing the experimental data and microstructure characteristic of these reported high-strength nano-structured steels,it is concluded that the basic approaches for si-multaneously optimizing the strength and ductility,such as second-phase nano-precipitate,micro/nanocrystalline composite structure,and multiple phase heterogeneous structure.The mechanism of these methods is to improve the strain harding ability of nano/ultrafine grained steels by tuning the structure,so as to maintain uniform plastic deformation or improve the plasticity by phase transformation.These heterogeneous nanostructures are similar to composites,and share common material design and mechanical principles.This review introduces the commonly used strengthening methods for steels.This artical also summarizes the methods for improving the plasti-city of nano/ultra-fine grained high-strength steels,especially by highlighting some novel nanostructured designs to achieve high-strength and high-plasticity of these steels,and discusses the deformation mechanism of these high performance steels.It is expected to provide inspiration for research on enhancing plasticity of the nano/ultra-fine grained high-strength steels.
作者
石玉
李正宁
盛捷
喇培清
SHI Yu;LI Zhengning;SHENG Jie;LA Peiqing(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;School of Materials Science and Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2021年第7期7155-7161,共7页
Materials Reports
基金
国家自然科学基金项目(51561020,51911530119)。