Abstract
It is necessary to know the effect by different conditions in order to consider the purpose of applications of a material and to estimate the properties required thereof. As an example, the authors made the static tensile test, the torsional fatigue test, and the repeated as well as the simple impact test, the results of which were compared with each other and considered with reference to the effect on the resistance to slip and to decomposition. It has been made clear that the mechanical properties are different according with forms and manners of loading, and that, in the phenomenon of temper-brittleness, the slip resistance has been increased by tempering and also the slip resistance enhanced with the increase of the silp velocity (due to the increase of stress velocity), and that both factors have come to check the slip deformation even at the stress velocity below that of the Charpy impact test. According to the idea of the transition velocity in relation to the impact, it is possible to consiedr that this transition velocity has been removed to the low-speed side by embrittlement. However, the effect on the static and fatigue test was very slight even in specimens which were presumed to have been embrittled considerably by the Charpy impact test.
