In this paper the mechanical properties of armco-iron are studied experimentally. The ultrasonic testing machine USF-2000 was used to carry out fatigue tests involving 106–1010 loading cycles. The frequency of loading is 19.5 ± 0.5 kHz. Based on the experimental data, the Wöhler curve was obtained. For the analysis of physical condition, two new sensors were designed, one of which measured the electric resistance of the sample and the other measured the magnetic permeability. Second measuring method can be applied to ferromagnetic materials only, though it may be useful for studying the mechanical properties of metals in general. It was shown that the significant changes in physical processes accompanying the evolution of structural defects in the material were observed in the final stages of the experiment. The applied measurement techniques allowed us to exactly determine the time of fatigue crack initiation below the surface the material, which cannot be monitored by the standard optic methods.

中文翻译：

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疲劳试验中Armco-iron的机械性能研究

本文通过实验研究了防铁的机械性能。超声波测试机USF-2000用于进行涉及106-1010次加载循环的疲劳测试。加载频率为19.5±0.5 kHz。根据实验数据，获得了沃勒曲线。为了分析物理状况，设计了两个新的传感器，其中一个测量样品的电阻，另一个测量磁导率。尽管第二种测量方法通常可用于研究金属的机械性能，但它只能应用于铁磁材料。结果表明，在实验的最后阶段观察到了伴随材料中结构缺陷演变的物理过程的显着变化。