Effects of heating temperature and atmosphere on element distribution and microstructure in high-Mn/Al austenitic low-density steel  

作　　者：Qi Zhang Guanghui Chen Yuemeng Zhu Zhengliang Xue Guang Xu 

机构地区：[1]State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China [2]Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,China [3]Zhejiang Red Eagle Group Co.,Ltd.,Huzhou 313000,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2024年第12期2670-2680,共11页矿物冶金与材料学报（英文版）

基　　金：gratefully acknowledge the financial support from the National Natural Science Foundation of China(No.U20A20270);China Postdoctoral Science Foundation(No.2022M722486).We would like to thank Dr.Wei Yuan at the Analytical&Testing Center of Wuhan University of Science and Technology for the help on EPMA analyses.

摘　　要：The elemental distribution and microstructure near the surface of high-Mn/Al austenitic low-density steel were investigated after isothermal holding at temperatures of 900-1200℃ in different atmospheres,including air,N_(2),and N_(2)+CO_(2).No ferrite was formed near the surface of the experimental steel during isothermal holding at 900 and 1000℃ in air,while ferrite was formed near the steel sur-face at holding temperatures of 1100 and 1200℃.The ferrite fraction was larger at 1200℃ because more C and Mn diffused to the sur-face,exuded from the steel,and then reacted with N and O to form oxidation products.The thickness of the compound scale increased owing to the higher diffusion rate at higher temperatures.In addition,after isothermal holding at 1100℃ in N_(2),the Al content near the surface slightly decreased,while the C and Mn contents did not change.Therefore,no ferrite was formed near the surface.However,the near-surface C and Al contents decreased after holding at 1100℃in the N_(2)+CO_(2)mixed atmosphere,resulting in the formation of a small amount of ferrite.The compound scale was thickest in N_(2),followed by the N_(2)+CO_(2)mixed atmosphere,and thinnest in air.Overall,the element loss and ferrite fraction were largest after holding in air at the same temperature.The differences in element loss and ferrite frac-tion between in N_(2) and N_(2)+CO_(2)atmospheres were small,but the compound scale formed in N_(2) was significantly thicker.According to these results,N_(2)+CO_(2)is the ideal heating atmosphere for the industrial production of high-Mn/Al austenitic low-density steel.

关 键 词：low-density steel oxidation MICROSTRUCTURE element distribution compound scale 

分 类 号：TG142.1[一般工业技术—材料科学与工程]