Pitoňák Martin, Ondruš Ján, Minárik Peter, Kubjatko Tibor, Neslušan Miroslav
Faculty of Civil Engineering, University of Žilina, Univerzitná 1, 01026 Zilina, Slovakia.
The Faculty of Operation and Economics of Transport and Communications, University of Žilina, Univerzitná 1, 01026 Zilina, Slovakia.
Materials (Basel). 2022 Mar 3;15(5):1898. doi: 10.3390/ma15051898.
This study deals with monitoring of Zn layer heterogeneity on the flange of steel road barriers using magnetic measurements. The Barkhausen noise technique is employed for such purpose, and parameters extracted from Barkhausen noise signals are correlated with the true thickness of the Zn layer. The true values of the Zn layer were obtained from the metallographic images, as well as the thickness gauge CM-8825FN (Guangzhou Landtek Instruments Co. Ltd., Guangzhou, China) device. It was observed that the diffusion region lies below the Zn protective layer, which makes the thickness of the Zn layer obtained from the CM-8825FN device thicker than that measured on the metallographic images. For this reason, the chemical gradient of Zn below the Zn layer can be reported, and it affects Barkhausen noise emission. Barkhausen noise decreases along with increasing thickness of the Zn layer, and Barkhausen noise envelopes are shifted to stronger magnetic fields. The number of strong MBN pulses drops down with the increasing thickness of Zn coating at the expense of the increasing number of the weak MBN pulses. The thickness of Zn coating can be polluted by the solidification of Zn melt after galvanizing. The presence of the diffusion layer dims the contrast between ferromagnetic and paramagnetic phases.
本研究通过磁测量对钢制道路护栏法兰上锌层的不均匀性进行监测。为此采用了巴克豪森噪声技术，从巴克豪森噪声信号中提取的参数与锌层的真实厚度相关。锌层的真实值是从金相图像以及厚度测量仪CM - 8825FN（广州兰泰克仪器有限公司，中国广州）设备获得的。观察到扩散区域位于锌保护层下方，这使得从CM - 8825FN设备获得的锌层厚度比在金相图像上测量的更厚。因此，可以报告锌层下方锌的化学梯度，并且它会影响巴克豪森噪声发射。巴克豪森噪声随着锌层厚度的增加而降低，并且巴克豪森噪声包络线向更强的磁场方向移动。强磁巴克豪森噪声脉冲的数量随着锌涂层厚度的增加而下降，而弱磁巴克豪森噪声脉冲的数量则增加。镀锌后锌熔体的凝固会污染锌涂层的厚度。扩散层的存在会使铁磁相和顺磁相之间的对比度降低。
