Abstract
It is a well-known fact that strength, especially fatigue strength is subject to residual stress located in various kinds of automobile parts. At our laboratory X-ray process has been adopted to measure the residual stress. In this connection, Mr. Motoyama and Mr. Miyata, our research engineers, have already made public several data. However, they involved more or less uncertainty concerning reliability of their accuracy. It was principally due to factitious and or mechanical errors produced in recording density curve of diffraction photograph through a microphotometer, or because of difficulties in determining representative position from density curve. In the present report, the writer states about some improvements on measurement of residual stress by Erescop: amendments of light receiving parts of a microphotometer for purpose of improving accuracy in measuring hardened steel and mobility of diffraction curve (Stress measurement), adoption of X-ray filter, redesign of X-ray bulb attachment, and adjustment of specimen surface.
