C-HRA-3镍基耐热合金真空感应熔炼脱氧脱氮热动力学研究  

Thermodynamics and Kinetics of Deoxidation and Denitrification in Vacuum Induction Melting of C-HRA-3 Nickel-based Heat Resisting Alloy

作　　者：李龙飞 林腾昌[1] 梁强[1] 何西扣[1] 陈正宗[1] 陈琨[1] LI Longfei;LIN Tengchang;LIANG Qiang;HE Xikou;CHEN Zhengzong;CHEN Kun(Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]钢铁研究总院有限公司,北京100081

出　　处：《铸造技术》2022年第7期559-566,共8页Foundry Technology

基　　金：中央企业自主投入研发专项重大基金(事20T61180ZD)。

摘　　要：为探明真空感应熔炼C-HRA-3镍基耐热合金脱氧和脱氮过程的热动力学规律,采用VIM-50型真空感应炉熔炼高纯合金原料,严格控制冶炼条件并取过程样检测,借助物理化学原理对实验结果进行分析。结果表明,精炼温度升高,C-HRA-3合金液中的平衡碳氧积增大而氮的平衡溶解度降低,真空度提高同时降低氧和氮的平衡溶解度。在实验冶炼条件(1582℃,2.7 Pa)下,平衡[O]和[N]含量分别为3.73×10^(-40)%和23.66×10^(-40)%。随着精炼期延长,[O][N]含量逐渐降低,精炼后期时受Mg O坩埚分解影响[O]含量二次升高。C-HRA-3合金真空碳脱氧反应和脱氮反应的限制性环节分别为[O]在液相边界层中的扩散和[N]原子在界面处的化学反应,经计算[O]在液相边界层中的平均传质系数k为2.68×10cm/s,脱氮反应为二级反应,反应表观速率常数为0.733 cm/s。In order to explore the thermodynamic law of the deoxidation and denitrification of C-HRA-3 nickel-base heat-resistant alloy by vacuum induction melting,high purity alloy raw materials were melted by VIM-50 vacuum induction furnace.The smelting conditions were strictly controlled.Samples were taken for monitoring and analysis.The results show that with the increase of refining temperature,the equilibrium carbon and oxygen product in C-HRA-3 alloy solution increases,while the nitrogen equilibrium solubility decreases.The vacuum degree is increased while the equilibrium solubility of oxygen and nitrogen is reduced.Under the experimental smelting condition(1582℃,2.7 Pa),the equilibrium[O]and[N]contents are 3.73×10^(-40)%and 23.66×10^(-40)%,respectively.With the prolongation of refining period,[O]and[N]contents gradually decreased,and the content of[O]increased twice due to the influence of Mg O crucible decomposition in later refining period.The limiting links of vacuum carbon deoxidation and denitrification of C-HRA-3 alloy are the diffusion of[O]in the liquid boundary layer and the chemical reaction of[N]atoms at the interface,respectively.The calculated average mass transfer coefficient kin the liquid boundary layer is 2.68×10cm/s.The denitrification reaction is a second-order reaction with an apparent rate constant of 0.733 cm/s.

关 键 词：C-HRA-3耐热合金 脱氧 脱氮 热动力学 真空感应熔炼 

分 类 号：TG132.33[一般工业技术—材料科学与工程]