Effect of Mn addition on microstructure and mechanical properties of GX40CrNiSi25-12 austenitic heat resistant steel  

作　　者：Guan-yu Jiang Meng-wu Wu Xiao-guang Yang Hui Wang Yu-yuan Zhu 

机构地区：[1]Hubei Key Laboratory of Advanced Technology for Automotive Components,Wuhan University of Technology,Wuhan 430070,China [2]Hubei Longzhong Laboratory,Xiangyang 441000,Hubei,China [3]Wescast Industries(China)Co.,Ltd.,Wuhan 430100,China

出　　处：《China Foundry》2024年第3期205-212,共8页中国铸造（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.52275370);the Key R&D Program of Hubei Province,China(Grant Nos.2022BAD100,2021BAA048);the Open Fund of Hubei Longzhong Laboratory(Grant No.2022ZZ-04).

摘　　要：Three types of steels were designed on the basis of GX40CrNiSi25-12 austenitic heat resistant steel by adding different Mn contents(2wt.%,6wt.%,and 12wt.%).Thermodynamic calculation,microstructure characterization and mechanical property tests were conducted to investigate the effect of Mn addition on the microstructure and mechanical properties of the austenitic heat resistant steel.Results show that the matrix structure in all the three types of steels at room temperature is completely austenite.Carbides NbC and M_(23)C_(6)precipitate at grain boundaries of austenite matrix.With the increase of Mn content,the number of carbides increases and their distribution becomes more uniform.With the Mn content increases from 1.99%to 12.06%,the ultimate tensile strength,yield strength and elongation increase by 14.6%,8.0%and 46.3%,respectively.The improvement of the mechanical properties of austenitic steels can be explained by utilizing classic theories of alloy strengthening,including solid solution strengthening,precipitation strengthening,and grain refinement.The increase in alloy strength can be attributed to solid solution strengthening and precipitation strengthening caused by the addition of Mn.The improvement of the plasticity of austenitic steels can be explained from two aspects:grain refinement and homogenization of precipitated phases.

关 键 词：austenitic heat resistant steel MANGANESE MICROSTRUCTURE mechanical properties 

分 类 号：TG142.73[一般工业技术—材料科学与工程]