磁巴克豪森噪声重构磁滞参数的硬度测定方法

Hardness determination method based on reconstructed magnetic hysteresis parameters with magnetic Barkhausen noise

针对铁磁性材料硬度指标的快速、定量、无损检测的实际需求,揭示了材料微观结构变化对磁巴克豪森噪声信号的影响机理,提出了采用磁巴克豪森噪声重构磁滞参数作为无损定量评价材料力学性能硬度指标。采用不同热处理制度对45钢试件进行处理,得到一组具有硬度梯度的标定试件;通过比较标定试件上不同激励电压对磁巴克豪森检测系统灵敏度的影响,选择最佳激励电压;采用磁巴克豪森噪声检测技术对不同热处理标定试件进行检测,对检测信号数据进行后处理,得到磁巴克豪森噪声能量滞后周期循环曲线,即重构磁滞回线。计算不同热处理45钢标定试件4种重构磁滞参数,构建材料力学性能硬度指标、微观结构及4种重构磁滞参数之间的映射关系,得到磁巴克豪森噪声重构磁滞参数评价45钢硬度的标定模型,并对标定模型进行验证,标定模型预测硬度误差基本满足工程应用10%的指标要求。

Aiming at the practical requirement of rapid, quantitative and non-destructive testing of ferromagnetic material hardness property, this paper reveals the influence mechanism of material microstructure change on magnetic Barkhausen noise signal; it is proposed that magnetic Barkhausen noise reconstructed hysteresis parameters are used to evaluate the material hardness property non-destructively and quantitively. The 45 steel specimens were treated with different heat treatment methods to obtain a set of calibration specimens with different hardness. Through comparing the influence of different excitation voltage for the calibration specimens on the magnetic Barkhausen detection system sensitivity, the optimal exciting voltage was selected. Magnetic Barkhausen noise test technique was used to test the calibration specimens for different heat treatment methods; and the test data were post-processed, then, the magnetic Barkhausen noise energy hysteresis cycle curves were obtained, named reconstructed magnetic hysteresis loops. Four reconstructed hysteresis parameters of 45 steel calibration specimens for different heat treatment methods were calculated, the mapping relationships of the material hardness property, microstructure and four reconstructed hysteresis parameters were established, then the calibration model that uses magnetic Barkhausen noise reconstructed hysteresis parameters to evaluate the hardness of 45 steel specimens was established and verified, the prediction hardness error of the model basically meets the requirement of 10% for the engineering application.