{"title":"Influence of softening annealing on microstructural heredity and mechanical properties of medium-Mn steel","authors":"Fanglin Ding, Qinyi Guo, B. Hu, H. Luo","doi":"10.20517/microstructures.2022.01","DOIUrl":null,"url":null,"abstract":"Softening annealing (SA) is often required for producing medium-Mn steels (MMS) as it lowers hardness so that they can be cold rolled to reduce thickness. The influences of different SA processes on the microstructural heredity during the processing route and the final tensile properties were studied. It was found that the SA process could either intensify or weaken the influence of the Mn segregation resulting from solidification on the subsequent microstructural evolution during the process, i.e., microstructural heredity. In the case when no SA was employed, both recrystallization and rapid growth of ferrite grains preceded the reverse austenitic transformation during the intercritical annealing (IA) in the Mn-lean regions, where very coarse ferrite grains were formed. This deteriorated ductility was due to the propagation of cracking along the boundary of the coarse-grained and fine-grained regions. In contrast, SA at a sufficiently high temperature could dissolve cementite, producing uniformly distributed austenite grains. They transformed to martensite during cold rolling but were reborn during IA. As a result, ultrafine austenite and ferrite grains were uniformly distributed, which improved ductility significantly. This study hints at a new approach to altering the microstructural heredity resulting from the heterogeneous Mn distribution in MMS.","PeriodicalId":22044,"journal":{"name":"Superlattices and Microstructures","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Superlattices and Microstructures","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.20517/microstructures.2022.01","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
引用次数: 0
Abstract
Softening annealing (SA) is often required for producing medium-Mn steels (MMS) as it lowers hardness so that they can be cold rolled to reduce thickness. The influences of different SA processes on the microstructural heredity during the processing route and the final tensile properties were studied. It was found that the SA process could either intensify or weaken the influence of the Mn segregation resulting from solidification on the subsequent microstructural evolution during the process, i.e., microstructural heredity. In the case when no SA was employed, both recrystallization and rapid growth of ferrite grains preceded the reverse austenitic transformation during the intercritical annealing (IA) in the Mn-lean regions, where very coarse ferrite grains were formed. This deteriorated ductility was due to the propagation of cracking along the boundary of the coarse-grained and fine-grained regions. In contrast, SA at a sufficiently high temperature could dissolve cementite, producing uniformly distributed austenite grains. They transformed to martensite during cold rolling but were reborn during IA. As a result, ultrafine austenite and ferrite grains were uniformly distributed, which improved ductility significantly. This study hints at a new approach to altering the microstructural heredity resulting from the heterogeneous Mn distribution in MMS.
期刊介绍:
Micro and Nanostructures is a journal disseminating the science and technology of micro-structures and nano-structures in materials and their devices, including individual and collective use of semiconductors, metals and insulators for the exploitation of their unique properties. The journal hosts papers dealing with fundamental and applied experimental research as well as theoretical studies. Fields of interest, including emerging ones, cover:
• Novel micro and nanostructures
• Nanomaterials (nanowires, nanodots, 2D materials ) and devices
• Synthetic heterostructures
• Plasmonics
• Micro and nano-defects in materials (semiconductor, metal and insulators)
• Surfaces and interfaces of thin films
In addition to Research Papers, the journal aims at publishing Topical Reviews providing insights into rapidly evolving or more mature fields. Written by leading researchers in their respective fields, those articles are commissioned by the Editorial Board.
Formerly known as Superlattices and Microstructures, with a 2021 IF of 3.22 and 2021 CiteScore of 5.4