返回料添加比例对高温合金夹杂物析出行为的影响  

Effect of returned materials addition ratio on precipitation behavior of inclusions in superalloy

作　　者：薛辉[1] 高锦国[2] 赵朋 李楠 刘威[2] 杨树峰[2,3] XUE Hui;GAO Jinguo;ZHAO Peng;LI Nan;LIU Wei;YANG Shufeng(Institute for Carbon Neutrality,University of Science and Technology Beijing,Beijing 100083,China;School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学碳中和研究院,北京100083 [2]北京科技大学冶金与生态工程学院,北京100083 [3]北京科技大学钢铁冶金新技术国家重点实验室,北京100083

出　　处：《中国冶金》2024年第1期27-35,89,共10页China Metallurgy

基　　金：国家重点研发计划资助项目(2021YFB3700402)。

摘　　要：为实现高返回比高温合金洁净化冶炼,研究不同返回料添加比例对高温合金冶炼过程夹杂物演变规律的影响,并结合热力学计算讨论夹杂物析出行为和生成机理。结果表明,返回料添加对高温合金夹杂物种类无明显影响,但对夹杂物数量和尺寸分布影响较大。随返回料比例从0%增加至60%,夹杂物数量密度由19.30个/mm^(2)增加至30.74个/mm^(2),其中以氧化物为核心的碳氮化物复合夹杂由4.47个/mm^(2)增加至10.11个/mm^(2),大尺寸(粒径大于5μm)夹杂物所占比例由8.7%增加到13.9%。热力学计算结果表明,MgO·Al_(2)O_(3)夹杂物的理论形核半径随熔体中氧活度的增加而减小,且该夹杂物与TiN夹杂物的晶格错配度较低。添加返回料相比全新料会引入更多的杂质元素,导致MgO·Al_(2)O_(3)夹杂物形核率显著上升,并促进了TiN、Ti(C,N)夹杂物的非均匀形核。形核动力学计算结果表明,返回料添加比例增大,体系中氮的浓度增大,TiN夹杂物更早析出,且析出尺寸也逐渐增大。研究结果可为高温合金低成本生产和洁净化冶炼提供必要的理论基础和数据支撑。In order to realize the pure smelting of superalloy with high return ratio,the effects of different addition ratios of returned materials on the evolution of inclusions in superalloy smelting process were studied,and the precipitation behavior and formation mechanism of inclusions were discussed in combination with thermodynamic calculations.The results show that the addition of returned material has no obvious effect on the types of inclusions in superalloys,but has a great influence on the number and size distribution of inclusions.As the returned material ratio increases from 0%to 60%,the number density of inclusions increases from 19.30 pieces/mm^(2) to 30.74 pieces/mm^(2).Among them,the number of carbonitride composite inclusions with oxide as the core increases from 4.47 pieces/mm^(2) to 10.11 pieces/mm^(2),and the proportion of large size(particle size greater than 5μm)inclusions increases from 8.7%to 13.9%.Thermodynamic calculation results show that the theoretical nucleation radius of MgO·Al_(2)O_(3) inclusions decreases with the increase of oxygen activity in the melt,and the lattice mismatch between MgO·Al_(2)O_(3) inclusions and TiN inclusions is low.Compared with the new material,the addition of returned material brings more impurity elements,which leads to a significant increase in the nucleation rate of MgO·Al_(2)O_(3) inclusions and promotes the non-uniform nucleation of TiN and Ti(C,N)inclusions.The calculation results of nucleation kinetics show that with the increase of returned material proportion,the concentration of nitrogen in the system increases,TiN inclusions precipitate earlier,and the size of precipitation also increases gradually.The research results can provide necessary theoretical basis and data support for low-cost production and purification smelting of superalloys.

关 键 词：高温合金 返回料 真空感应熔炼 夹杂物 形核热力学 

分 类 号：TG132.3[一般工业技术—材料科学与工程]