Mechanisms of Reverted Austenite and Grain Refinement via Neutron Diffraction for Enhancing Mechanical Properties of 304 Stainless Steel

IF 4 3区 材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY
Donghun Lee, Baek-Seok Seong, Byungrok Moon, Bong Cheon Park, Changhoon Lee, Sung-Dae Kim, Namhyun Kang
{"title":"Mechanisms of Reverted Austenite and Grain Refinement via Neutron Diffraction for Enhancing Mechanical Properties of 304 Stainless Steel","authors":"Donghun Lee,&nbsp;Baek-Seok Seong,&nbsp;Byungrok Moon,&nbsp;Bong Cheon Park,&nbsp;Changhoon Lee,&nbsp;Sung-Dae Kim,&nbsp;Namhyun Kang","doi":"10.1007/s12540-024-01881-9","DOIUrl":null,"url":null,"abstract":"<div><p>Austenitic stainless steels possess excellent properties; however, their low yield strengths limit their applications in structural settings. In this study, neutron diffraction was employed along with conventional microstructural characterization to investigate the microstructural and strain behaviors of reverted and deformed austenites in specimens rolled under cryogenic temperature (CRT) and room temperature (RT) and annealed at various temperatures, where different reversion mechanisms occur. After austenite reversion annealing, the yield strength was superior to that of the as-received specimens, regardless of the rolling conditions. The CRT specimens showed high strengths owing to grain refinement. They were composed of strain-induced martensite, leading to the formation of fine reverted austenite. The RT specimens consisted mostly of deformed austenite, resulting in coarse austenite. For the annealing at 590 °C, the reverted austenite grew under strain induced by the martensite. At 900 °C, recrystallization occurred during the heating process, with the fine grains growing preferentially, decreasing the yield strength. At 750 °C, reverted austenite formed through both the diffusional and diffusionless mechanisms. The diffusionally reverted austenite grew without strain, forming abnormally coarse grains, whereas the diffusionless reverted austenite produced recrystallized fine grains. Neutron diffraction analysis revealed that the annealed CRT specimens underwent full recrystallization and the RT specimens underwent incomplete recrystallization, indicating that the deformed austenite recrystallized more slowly than the diffusionless reverted austenite. Superior yield strength and elongation were achieved by annealing at the CRT for 1 min owing to the grain refinement combined with diffusional reverted austenite and diffusionless reverted austenite.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":703,"journal":{"name":"Metals and Materials International","volume":"31 8","pages":"2279 - 2296"},"PeriodicalIF":4.0000,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Metals and Materials International","FirstCategoryId":"88","ListUrlMain":"https://link.springer.com/article/10.1007/s12540-024-01881-9","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0

Abstract

Austenitic stainless steels possess excellent properties; however, their low yield strengths limit their applications in structural settings. In this study, neutron diffraction was employed along with conventional microstructural characterization to investigate the microstructural and strain behaviors of reverted and deformed austenites in specimens rolled under cryogenic temperature (CRT) and room temperature (RT) and annealed at various temperatures, where different reversion mechanisms occur. After austenite reversion annealing, the yield strength was superior to that of the as-received specimens, regardless of the rolling conditions. The CRT specimens showed high strengths owing to grain refinement. They were composed of strain-induced martensite, leading to the formation of fine reverted austenite. The RT specimens consisted mostly of deformed austenite, resulting in coarse austenite. For the annealing at 590 °C, the reverted austenite grew under strain induced by the martensite. At 900 °C, recrystallization occurred during the heating process, with the fine grains growing preferentially, decreasing the yield strength. At 750 °C, reverted austenite formed through both the diffusional and diffusionless mechanisms. The diffusionally reverted austenite grew without strain, forming abnormally coarse grains, whereas the diffusionless reverted austenite produced recrystallized fine grains. Neutron diffraction analysis revealed that the annealed CRT specimens underwent full recrystallization and the RT specimens underwent incomplete recrystallization, indicating that the deformed austenite recrystallized more slowly than the diffusionless reverted austenite. Superior yield strength and elongation were achieved by annealing at the CRT for 1 min owing to the grain refinement combined with diffusional reverted austenite and diffusionless reverted austenite.

Graphical Abstract

Abstract Image

通过中子衍射还原奥氏体和细化晶粒提高304不锈钢力学性能的机理
奥氏体不锈钢具有优异的性能;然而,它们的低屈服强度限制了它们在结构设置中的应用。在本研究中,利用中子衍射和常规的显微组织表征,研究了低温(CRT)和室温(RT)轧制和不同温度退火试样的显微组织和变形奥氏体的应变行为,其中不同的逆转机制发生。无论轧制条件如何,经奥氏体还原退火后的屈服强度均优于原状试样。由于晶粒细化,CRT试样表现出较高的强度。它们由应变诱导马氏体组成,形成细小的还原奥氏体。RT试样主要由形变奥氏体组成,形成粗奥氏体。在590℃退火时,在马氏体诱发的应变下,还原奥氏体生长。在900℃时,加热过程中发生再结晶,细晶粒优先长大,屈服强度降低。在750℃时,通过扩散机制和无扩散机制形成还原奥氏体。扩散还原奥氏体在无应变的情况下生长,形成异常粗晶粒,而无扩散还原奥氏体则产生再结晶细晶粒。中子衍射分析表明,退火后的CRT试样发生完全再结晶,而RT试样发生不完全再结晶,表明变形奥氏体的再结晶速度比无扩散还原奥氏体慢。在CRT下退火1 min后,由于晶粒细化,扩散还原奥氏体和无扩散还原奥氏体相结合,获得了较好的屈服强度和延伸率。图形抽象
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Metals and Materials International
Metals and Materials International 工程技术-材料科学:综合
CiteScore
7.10
自引率
8.60%
发文量
197
审稿时长
3.7 months
期刊介绍: Metals and Materials International publishes original papers and occasional critical reviews on all aspects of research and technology in materials engineering: physical metallurgy, materials science, and processing of metals and other materials. Emphasis is placed on those aspects of the science of materials that are concerned with the relationships among the processing, structure and properties (mechanical, chemical, electrical, electrochemical, magnetic and optical) of materials. Aspects of processing include the melting, casting, and fabrication with the thermodynamics, kinetics and modeling.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:604180095
Book学术官方微信