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金属磁记忆检测技术是一种可早期检测铁磁构件应力集中程度的新方法,但进一步定量评价和广泛应用的瓶颈问题是复杂的应力磁化反转特征。对40Cr钢圆棒试件在不同最大拉力下进行反复加载-卸载拉伸试验,测定试件表面某确定点处漏磁场与拉应力的关系。试验结果表明,当试件处于弹性变形阶段时,漏磁场强度与拉应力的变化规律为线性关系;当试件受力超过屈服强度时,漏磁场强度与拉应力的变化规律变为折线,表现为先减小后增大再减小的应力磁化反转现象。随着最大拉力的增大,应力磁化反转极值点位置向较高拉应力方向移动,漏磁场强度最大变化量ΔBmax也逐渐增大。
Metal magnetic memory testing is a new method for early detection of stress concentration in ferromagnetic components. However, the bottleneck problem for further quantitative evaluation and wide application is the complex feature of stress-magnetization reversal. The 40Cr steel round bar specimens under different maximum tensile load-unloading tensile test to determine the surface of the specimen at a certain point of leakage magnetic field and tensile stress relationship. The experimental results show that when the specimen is in the stage of elastic deformation, the variation of the leakage magnetic field and the tensile stress is linear. When the stress of the specimen exceeds the yield strength, the variation of the leakage magnetic field strength and tensile stress becomes a polyline, For the first to reduce and then reduce the stress magnetization reversal phenomenon. With the increase of the maximum tensile force, the extreme point of magnetization reversal moves to the direction of higher tensile stress, and the maximum variation of magnetic flux leakage strength, ΔBmax, also gradually increases.