310S不锈钢表面渗铝方法及铝扩散机制的研究

发布时间：2018-03-22 17:57

本文选题：铝涂层　切入点：热喷涂　出处：《华东理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：310S不锈钢作为环形退火炉设备的内罩材料,由于长期使用在高温环境下,易发生高温氧化失效,因此本文研究了提高310S不锈钢材料抗高温氧化性能的方法,以及高温条件下的铝涂层与310S不锈钢基体间的互扩散机制。在金属氧化的过程中,若金属表面生成稳定、致密的氧化膜,即可以起到隔离氧气进入基体避免金属进一步氧化的作用,使得金属具有一定的抗氧化性能。铝元素是生成优良保护性氧化膜的首选元素,本文采用了电弧喷涂工艺和固体粉末渗铝工艺分别在310S不锈钢表面制备铝涂层,在不同温度下对铝涂层进行扩散处理,制备得到了各种不同形态的扩散铝涂层,以提高基体材料的抗高温氧化能力。借助于金相显微镜(OM)和电子显微镜(SEM)观察、能谱分析仪(EDS)以及X射线衍射仪(XRD)分析等方法,分析了铝化物涂层的组织结构变化,基体表面扩散层的形成以及它们对铝元素扩散规律的影响,并运用俣野法(Boltzmann-Matano法)计算铝原子在310S不锈钢基体中的扩散系数。将实验得到的扩散系数带入有限元模型进行数值仿真,并与实验获得的铝元素在基体中的分布结果进行对比,验证了扩散模型及扩散系数的准确性。最后,对扩散试样和未扩散试样分别进行高温氧实验及氧化动力学分析,获得最佳的表面处理工艺来提高310S不锈钢材料的抗高温氧化性能。
[Abstract]:The 310s stainless steel is used as the inner cover material of the annular annealing furnace. Because it is easy to be oxidized at high temperature for a long time, the method of improving the high temperature oxidation resistance of the 310S stainless steel is studied in this paper. And the interdiffusion mechanism between aluminum coating and 310S stainless steel substrate at high temperature. In the process of metal oxidation, a stable and dense oxide film is formed on the metal surface. That is, the oxygen can be isolated into the matrix to avoid further oxidation of the metal, and the metal has a certain oxidation resistance. Aluminum is the first choice element to form a good protective oxide film. In this paper, aluminum coatings were prepared on 310s stainless steel by arc spraying process and solid powder aluminizing process, and various kinds of diffused aluminum coatings were prepared by diffusion treatment at different temperatures. In order to improve the oxidation resistance of matrix materials at high temperature, the microstructure changes of aluminized coatings were analyzed by means of metallographic microscope (OM) and electron microscope (SEM) observation, energy spectrum analyzer (EDS) and X-ray diffractometer (XRD) analysis. The formation of diffusion layers on the matrix surface and their influence on the diffusion law of aluminum, The diffusion coefficient of aluminum atoms in 310s stainless steel matrix is calculated by using the Minamata field method and Boltzmann-Matano method. The diffusion coefficient obtained from the experiment is brought into the finite element model for numerical simulation, and the results are compared with the experimental results of the distribution of aluminum in the matrix. The accuracy of diffusion model and diffusion coefficient is verified. Finally, the high temperature oxygen test and oxidation kinetics analysis of diffusion and non-diffusion samples are carried out, respectively. The best surface treatment process was obtained to improve the oxidation resistance of 310s stainless steel at high temperature.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG174.4

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