{"title":"氮化钢中 Fe4N 化合物层的晶粒细化","authors":"Norimitsu Koga , Atsushi Yamashita , Ryusei Kato , Ryosuke Kanebu , Kenta Miyake , Yohei Hashimoto","doi":"10.1016/j.mtla.2024.102217","DOIUrl":null,"url":null,"abstract":"<div><p>This study elucidated the microstructure of the Fe<sub>4</sub>N (γ’) compound layer in specimens subjected to the nitriding to the specimens with various finished surfaces. Gyrofinishing produces a specimen surface with an ultra-fine-grained (UFGed) structure and a rough surface, whereas the buff-finished specimen exhibited a coarse grain but smooth surface. The γ’ grains formed on the gyrofinished specimens after nitriding were considerably finer and more equiaxial compared with those on the buff-finished specimen. The γ’ nucleated from the grain boundary in the matrix, indicating that the grain boundaries act as a nucleation site. Therefore, the UFGed structure promotes the nucleation of γ’ during the nitriding, resulting in fine grains. Numerous pores were formed in the γ’ layer of the gyrofinished specimen owing to the rough surface. The UFGed structure and surface roughness before nitriding are key factors for controlling the microstructure in the γ’ compound layer.</p></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"37 ","pages":"Article 102217"},"PeriodicalIF":3.0000,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Grain refinement of Fe4N compound layer in nitrided steel\",\"authors\":\"Norimitsu Koga , Atsushi Yamashita , Ryusei Kato , Ryosuke Kanebu , Kenta Miyake , Yohei Hashimoto\",\"doi\":\"10.1016/j.mtla.2024.102217\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>This study elucidated the microstructure of the Fe<sub>4</sub>N (γ’) compound layer in specimens subjected to the nitriding to the specimens with various finished surfaces. Gyrofinishing produces a specimen surface with an ultra-fine-grained (UFGed) structure and a rough surface, whereas the buff-finished specimen exhibited a coarse grain but smooth surface. The γ’ grains formed on the gyrofinished specimens after nitriding were considerably finer and more equiaxial compared with those on the buff-finished specimen. The γ’ nucleated from the grain boundary in the matrix, indicating that the grain boundaries act as a nucleation site. Therefore, the UFGed structure promotes the nucleation of γ’ during the nitriding, resulting in fine grains. Numerous pores were formed in the γ’ layer of the gyrofinished specimen owing to the rough surface. The UFGed structure and surface roughness before nitriding are key factors for controlling the microstructure in the γ’ compound layer.</p></div>\",\"PeriodicalId\":47623,\"journal\":{\"name\":\"Materialia\",\"volume\":\"37 \",\"pages\":\"Article 102217\"},\"PeriodicalIF\":3.0000,\"publicationDate\":\"2024-09-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Materialia\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S258915292400214X\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materialia","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S258915292400214X","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
摘要
本研究阐明了氮化试样中 Fe4N (γ') 化合物层的微观结构,以及试样的各种加工表面。陀螺抛光产生的试样表面具有超细晶粒(UFGed)结构和粗糙的表面,而抛光试样则表现出粗晶粒但光滑的表面。氮化处理后,回火处理试样上形成的γ'晶粒比抛光处理试样上的γ'晶粒要细得多,而且更加等轴。γ'晶粒从基体中的晶界成核,表明晶界是成核部位。因此,UFGed 结构在氮化过程中促进了 γ' 的成核,从而产生了细小的晶粒。由于表面粗糙,回火试样的γ'层中形成了许多气孔。氮化前的 UFGed 结构和表面粗糙度是控制 γ'复合层微观结构的关键因素。
Grain refinement of Fe4N compound layer in nitrided steel
This study elucidated the microstructure of the Fe4N (γ’) compound layer in specimens subjected to the nitriding to the specimens with various finished surfaces. Gyrofinishing produces a specimen surface with an ultra-fine-grained (UFGed) structure and a rough surface, whereas the buff-finished specimen exhibited a coarse grain but smooth surface. The γ’ grains formed on the gyrofinished specimens after nitriding were considerably finer and more equiaxial compared with those on the buff-finished specimen. The γ’ nucleated from the grain boundary in the matrix, indicating that the grain boundaries act as a nucleation site. Therefore, the UFGed structure promotes the nucleation of γ’ during the nitriding, resulting in fine grains. Numerous pores were formed in the γ’ layer of the gyrofinished specimen owing to the rough surface. The UFGed structure and surface roughness before nitriding are key factors for controlling the microstructure in the γ’ compound layer.
期刊介绍:
Materialia is a multidisciplinary journal of materials science and engineering that publishes original peer-reviewed research articles. Articles in Materialia advance the understanding of the relationship between processing, structure, property, and function of materials.
Materialia publishes full-length research articles, review articles, and letters (short communications). In addition to receiving direct submissions, Materialia also accepts transfers from Acta Materialia, Inc. partner journals. Materialia offers authors the choice to publish on an open access model (with author fee), or on a subscription model (with no author fee).