Mo对炼镁还原罐用奥氏体耐热钢组织及高温抗氧化性能的影响  

Effect of Mo Addition on Microstructure and High Temperature Oxidation Resistance of Austenitic Heat Resistant Steel for Magnesium Reduction Tank

作　　者：李燕昭 王光辉[1] 杜学山[1] 孙玉福[1] LI Yan-zhao;WANG Guang-hui;DU Xue-shan;SUN Yu-fu(School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,Henan,China)

机构地区：[1]郑州大学材料科学与工程学院

出　　处：《铸造》2019年第11期1215-1219,共5页Foundry

摘　　要：利用OM、SEM、XRD研究了Mo对炼镁还原罐用奥氏体耐热钢的显微组织及高温抗氧化性能的影响。结果表明:未添加Mo的耐热钢基体组织为奥氏体+第二相(M23C6、M7C3、Cr2Fe14C和WC);添加Mo后有新相Mo2C生成,组织得到细化,碳化物随Mo含量的增加而长大。耐热钢在1 200℃的抗氧化性随Mo含量的增加先升高后降低;当Mo含量为0.49%时,高温抗氧化性最优。抗氧化性的提高主要归因于Mo含量的添加阻碍了耐热钢元素向外扩散和晶粒细化提供的短路扩散通道加速了保护性氧化膜的生成;抗氧化性的降低主要归因于晶粒进一步细化,不利于保护性氧化膜的生成。The effect of Mo on the microstructure and high temperature oxidation resistance of austenitic heat-resistant steel for magnesium reduction tank was studied by using OM, SEM and XRD. The results show that the matrix structure of the heat-resistant steel without Mo is austenite + second phase(M23C6, M7C3, Cr2Fe14C and WC). After Mo addition, new phases Mo2C is formed, and the microstructure is refined. Carbides grow up with the increase of Mo content. The oxidation resistance of heat-resistant steel at 1 200 ℃ increases first and then decreases with an increase in Mo content. When the Mo content is 0.49%, the oxidation resistance of steel at high temperature is the best. The increase of oxidation resistance is mainly attributed to the fact that the addition of Mo hinders the outward diffusion of elements in the heat-resistant steel and the shortcircuit diffusion channel provided by grain refinement accelerates the formation of protective oxide film. The decrease of oxidation resistance is mainly attributed to the further refinement of grains, which is not conducive to the formation of protective oxide films.

关 键 词：还原罐 奥氏体耐热钢 Mo添加 高温抗氧化性 

分 类 号：TG142.73[一般工业技术—材料科学与工程]