多频电涡流法测量连铸坯壳厚度的方法

以连铸结晶器内的45号钢薄板坯为研究对象,采用有限元软件ANSYS建立多频电涡流测多层板厚度模型。采用激励频率优选法选择2个最优频率对传感器线圈进行激励,研究固液相区板层总厚度不变,凝固坯壳层厚度变化以及固液相区板层和凝固坯壳厚度层同时变化的2种情况下传感器输出信号规律。通过Matlab对数据进行拟合和对拟合进行残差分析。研究结果表明:多频测量坯壳厚度的激励频率可以通过频率优选法进行选取,同时坯壳厚度变化与电压幅值呈现出良好的线性关系,通过残差图也可以看出各个采样点的拟合情况良好。

Multi-frequency eddy current measurement method of continuous casting billet shell thickness

The finite element software ANSYS was adopted to establish the multi-frequency eddy current measure-ment model of multilayer thickness with 45 steel slabs in the continuous casting mold.The excitation frequency se-lection method was used to select the two optimal frequencies to excite the sensor coil.And then two cases were studied to get the law of sensor output singal:the thickness of solid layer changed with fixed thickness of solidified shell layer,and the thickness of solid layer and solidified shell changed simultaneously.The residual analysis was studied after data were fitted by Matlab.The research results show that excitation frequency for multi-frequency measurement of the thickness of solidified shell can be selected by frequency preferred method,and there is a good linear relation between the thickness of shell and the voltage amplitude.The fitting result of each sampling point is good according to the residual diagram.