Basic Study on Stress Measurement Using Slip-initiation Phenomenon in Electro-deposited Iron

Abstract

Using slip-initiation phenomenon by fatigue in an electro-deposited iron, we propose a method of measurement of the stresses in machine elements under fluctuating service loads. In the method, both the direct iron-plating and adhesion of deposited iron-foil are utilized. Accuracy of the iron-foil method, however, is far superior to that of the direct plating method. Basic properties of the iron-plating for stress measurement, namely, applicable test temperature, and effects of test interruptions and grain size of the plating on slip-initiation are examined. When the iron-foil method is applied, the stress-concentration factors in notched specimens are obtained at various temperatures. The results are in good agreement with the theoretical and experimental values obtained previously. Consequently, it is confirmed that the present method utilizing the deposited iron-foil is effectively applicable to the measurement of cyclic stress in the range from room temperature to 250°C.