磁性金属材料残余奥氏体测量方法研究

发布时间：2019-01-27 19:01

【摘要】：金属材料中残余奥氏体会影响其硬度、耐磨性、接触疲劳性等材料物理性能和机械性能。在外界应力和摩擦作用下金属材料中残余奥氏体会发生相变,严重时可能引发金属材料失效等安全事故。为保证金属材料品质,了解金属材料服役状态,需要对金属材料中残余奥氏体含量进行测量。磁测法作为一种非接触的测量方法,具有成本低,周期短,对材料无损伤的优点,应用前景十分广泛。本文在分析了国内外关于磁测法测量金属材料残余奥氏体含量的基础上,对交流磁化过程中金属材料残余奥氏体含量测量进行了研究,主要包括:(1)设计了一种九脚结构的残余奥氏体含量测量磁传感器,并利用有限元电磁仿真软件ANSYS Maxwell对九脚磁传感器建模分析,研究了磁传感器结构参数、线圈参数、激励参数等对九脚磁传感器输出信号和磁特性的影响,最后基于最优原则,确定了九脚磁传感器相关参数。(2)基于磁测法原理推导了交流磁化过程中金属材料残余奥氏体含量与金属材料交流磁导率有效值的计算模型,建立了基于九脚磁传感器模型的金属材料残余奥氏体含量计算模型,为交流磁化过程中测量金属材料残余奥氏体含量提供理论基础。(3)基于本文研究的交流磁化过程中金属材料残余奥氏体含量测量方法设计和制作了金属材料残余奥氏体含量测量系统,分析了九脚磁传感器温度变化和试样残余磁化对系统输出的影响,结果表明温度变化和试样残余磁化对系统测量结果影响非常明显,在测量材料残余奥氏体含量之前应对试样进行退磁操作和对磁传感器不少于150s的预热操作,以保证测量结果的准确性和系统的可重复性。(4)对Q235低碳钢材料进行了残余奥氏体含量测量实验,将试验中测量结果与X射线衍射仪(标准方法)测量结果进行了对比和数据分析,结果表明本文中的系统测量结果与X射线衍射仪测量结果具有较高的一致性,证明了本文所建立的交流磁化过程中金属材料残余奥氏体计算模型的正确性以及测量系统的有效性。
[Abstract]:The residual austenite in metallic materials will affect the physical and mechanical properties of such materials as hardness, wear resistance and contact fatigue. The residual austenite in metal materials will undergo phase transformation under external stress and friction, which may lead to safety accidents such as failure of metal materials. In order to ensure the quality of metal materials and understand the service state of metal materials, it is necessary to measure the content of residual austenite in metal materials. As a non-contact measurement method, magnetic measurement has the advantages of low cost, short period and no damage to materials. Based on the analysis of the measurement of residual austenite content in metal materials by magnetic measurement at home and abroad, the measurement of residual austenite content in metal materials during alternating current magnetization is studied in this paper. The main contents are as follows: (1) A magnetic sensor is designed to measure the residual austenite content in a nine-legged structure. The magnetic sensor is modeled and analyzed by using the finite element electromagnetic simulation software ANSYS Maxwell. The structure parameters and coil parameters of the magnetic sensor are studied. The effects of excitation parameters on the output signal and magnetic characteristics of the nine-legged magnetic sensor are discussed. Finally, based on the optimal principle, The related parameters of the nine-pin magnetic sensor are determined. (2) based on the principle of magnetic measurement, the calculation model of the residual austenite content of metal material and the effective value of AC permeability of metal material in the process of alternating current magnetization is derived. The calculation model of residual austenite content in metal materials based on the nine-footed magnetic sensor model is established. It provides a theoretical basis for the measurement of residual austenite content in metal materials during alternating current magnetization. (3) based on the research in this paper, the measurement method of residual austenite content in metal materials during AC magnetization is designed and fabricated. Residual austenite content measurement system, The effect of temperature change and residual magnetization of the sample on the output of the system is analyzed. The results show that the temperature change and the residual magnetization of the sample have a very obvious effect on the measurement results of the system. The sample shall be demagnetized before measuring the residual austenite content of the material and preheated to the magnetic sensor for not less than 150 s, In order to ensure the accuracy of the measurement results and the repeatability of the system. (4) the residual austenite content of Q235 low carbon steel was measured. The experimental results are compared with those measured by X-ray diffractometer (standard method). The results show that the system measurement results in this paper are in good agreement with the X-ray diffractometer measurements. It is proved that the calculation model of residual austenite in metal material and the validity of measuring system are established in this paper.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG115.5

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