{"title":"Thermal stability of retained austenite and mechanical properties of medium-Mn steel during tempering treatment","authors":"Xiao-li Zhao , Yong-jian Zhang , Cheng-wei Shao , Wei-jun Hui , Han Dong","doi":"10.1016/S1006-706X(17)30123-1","DOIUrl":null,"url":null,"abstract":"<div><p>The thermal stability of retained austenite (RA) and the mechanical properties of the quenched and intercritical annealed 0.1C-5Mn steel with the starting ultrafine lamellar duplex structure of ferrite and retained austenite during tempering within the range from 200 to 500 °C were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and tensile testing. The results showed that there was a slight decrease in the RA volume fraction with increasing tempering temperature up to 400 °C. This caused a slight increase in the ultimate tensile strength (UTS) and a slight decrease in the total elongation (TE); thus, the product of UTS to TE (UTS×TE) as high as 31 GPa • % was obtained and remained nearly unchanged. However, a portion of the RA began to decompose when tempered at 500 °C and thus caused a ∼35% decrease of the RA fraction and a ∼16% decrease of the value of UTS×TE. It is concluded that the ultrafine lamellar duplex structure is rather stable and the excellent combination of strength and ductility could be retained with tempering temperature up to 400 °C. Thus, thermal processes such as galvanization are feasible for the tested steel provided that their temperatures are not higher than 400 °C.</p></div>","PeriodicalId":64470,"journal":{"name":"Journal of Iron and Steel Research(International)","volume":null,"pages":null},"PeriodicalIF":3.1000,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1006-706X(17)30123-1","citationCount":"13","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Iron and Steel Research(International)","FirstCategoryId":"1087","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1006706X17301231","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"METALLURGY & METALLURGICAL ENGINEERING","Score":null,"Total":0}
引用次数: 13
Abstract
The thermal stability of retained austenite (RA) and the mechanical properties of the quenched and intercritical annealed 0.1C-5Mn steel with the starting ultrafine lamellar duplex structure of ferrite and retained austenite during tempering within the range from 200 to 500 °C were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and tensile testing. The results showed that there was a slight decrease in the RA volume fraction with increasing tempering temperature up to 400 °C. This caused a slight increase in the ultimate tensile strength (UTS) and a slight decrease in the total elongation (TE); thus, the product of UTS to TE (UTS×TE) as high as 31 GPa • % was obtained and remained nearly unchanged. However, a portion of the RA began to decompose when tempered at 500 °C and thus caused a ∼35% decrease of the RA fraction and a ∼16% decrease of the value of UTS×TE. It is concluded that the ultrafine lamellar duplex structure is rather stable and the excellent combination of strength and ductility could be retained with tempering temperature up to 400 °C. Thus, thermal processes such as galvanization are feasible for the tested steel provided that their temperatures are not higher than 400 °C.