{"title":"Design of tri-phase lamellar architectures for enhanced ductility in ultra-strong steel","authors":"","doi":"10.1016/j.matdes.2024.113328","DOIUrl":null,"url":null,"abstract":"<div><div>Achieving exceptional ductility in ultra-high strength steels has long been a formidable challenge, particularly when the yield strength reaches 2.0 GPa. In this study, we have designed an innovative tri-phase lamellar microstructure in medium Mn steel that successfully achieves both an ultrahigh yield strength of approximately 2.0 GPa and an impressive uniform elongation ranging from 22.5 % to 24.5 %. The ultra-high yield strength of this steel is primarily due to the ultrafine lamellar grain with high-density dislocations and HDI strengthening resulting from meticulously designed tri-phase lamellae. The remarkable ductility is attributed to the synergistic action of multiple plasticity mechanisms. The inherently excellent plasticity of the lamellar ferrite, in coordination with the lamellar martensite, generates significant HDI hardening, thereby suppressing the onset of necking in the early stages of deformation. During the mid-stage of deformation, high strain activates the transformation-induced plasticity effect in the highly stable austenite, which remains stable due to substantial HDI hardening and effectively mitigates strain localization. In the later stages of deformation, delamination cracking relieves stress accumulation at the interfaces, delaying material failure. These mechanisms elevate yield strength and uniform elongation product to 47.3 GPa·%, showcasing the tri-phase lamellar structure’s potential for ultrahigh-strength, high-ductility steels.</div></div>","PeriodicalId":383,"journal":{"name":"Materials & Design","volume":null,"pages":null},"PeriodicalIF":7.6000,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0264127524007032/pdfft?md5=e8e277209c0ec496e3bfe7b3bfe75a1d&pid=1-s2.0-S0264127524007032-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials & Design","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0264127524007032","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Achieving exceptional ductility in ultra-high strength steels has long been a formidable challenge, particularly when the yield strength reaches 2.0 GPa. In this study, we have designed an innovative tri-phase lamellar microstructure in medium Mn steel that successfully achieves both an ultrahigh yield strength of approximately 2.0 GPa and an impressive uniform elongation ranging from 22.5 % to 24.5 %. The ultra-high yield strength of this steel is primarily due to the ultrafine lamellar grain with high-density dislocations and HDI strengthening resulting from meticulously designed tri-phase lamellae. The remarkable ductility is attributed to the synergistic action of multiple plasticity mechanisms. The inherently excellent plasticity of the lamellar ferrite, in coordination with the lamellar martensite, generates significant HDI hardening, thereby suppressing the onset of necking in the early stages of deformation. During the mid-stage of deformation, high strain activates the transformation-induced plasticity effect in the highly stable austenite, which remains stable due to substantial HDI hardening and effectively mitigates strain localization. In the later stages of deformation, delamination cracking relieves stress accumulation at the interfaces, delaying material failure. These mechanisms elevate yield strength and uniform elongation product to 47.3 GPa·%, showcasing the tri-phase lamellar structure’s potential for ultrahigh-strength, high-ductility steels.
期刊介绍:
Materials and Design is a multi-disciplinary journal that publishes original research reports, review articles, and express communications. The journal focuses on studying the structure and properties of inorganic and organic materials, advancements in synthesis, processing, characterization, and testing, the design of materials and engineering systems, and their applications in technology. It aims to bring together various aspects of materials science, engineering, physics, and chemistry.
The journal explores themes ranging from materials to design and aims to reveal the connections between natural and artificial materials, as well as experiment and modeling. Manuscripts submitted to Materials and Design should contain elements of discovery and surprise, as they often contribute new insights into the architecture and function of matter.