Hwang Young-In, Kim Yong-Il, Seo Dae-Cheol, Seo Mu-Kyung, Lee Woo-Sang, Kwon Segon, Kim Ki-Bok
Safety Measurement Institute, Korea Research Institute of Standards and Science, 267, Gajeong-ro, Yuseong-gu, Daejeon 34113, Korea.
Department of Nano Science, University of Science and Technology, 217, Gajeong-ro, Yuseong-gu, Daejeon 34113, Korea.
Materials (Basel). 2021 Sep 17;14(18):5374. doi: 10.3390/ma14185374.
Residual stress, a factor affecting the fatigue and fracture characteristics of rails, is formed during the processes of fabrication and heat treatment, and is also generated by vertical loads on wheels due to the weight of vehicles. Moreover, damage to rails tends to accelerate due to the continuous increase in the number of passes and to the high speed of passing vehicles. Because this can have a direct effect on safety accidents, having a technique to evaluate and analyze the residual stresses in rails accurately is very important. In this study, stresses due to tensile loads applied to new rails and residual stresses remaining in used rails were measured by using magnetic Barkhausen noise method. First, a magnetization frequency and noise band suitable for the rails were selected. Moreover, by applying tensile loads to specimens and comparing the difference in magnetization amplitudes for each load, the stresses applied to the rails by using the magnetic Barkhausen noise method were measured, and the analysis of the results was verified. Based on these results, the difference in the results for the loads asymmetrically applied according to the wheel shape was analyzed by measuring for the head parts of used rails.
残余应力是影响钢轨疲劳和断裂特性的一个因素，它在制造和热处理过程中形成，也会因车辆重量导致车轮的垂直载荷而产生。此外，由于通过次数的不断增加和车辆通过速度的提高，钢轨的损伤往往会加速。因为这可能对安全事故产生直接影响，所以拥有一种准确评估和分析钢轨残余应力的技术非常重要。在本研究中，采用磁巴克豪森噪声法测量了施加在新钢轨上的拉伸载荷引起的应力以及使用过的钢轨中残留的残余应力。首先，选择了适合钢轨的磁化频率和噪声频段。此外，通过对试样施加拉伸载荷并比较每个载荷下磁化幅度的差异，测量了用磁巴克豪森噪声法施加在钢轨上的应力，并对结果分析进行了验证。基于这些结果，通过对使用过的钢轨头部进行测量，分析了根据车轮形状不对称施加载荷时结果的差异。
