부산대학교 도서관

The circumferential residual stress on the inner surface of a round pipe was measured by using the dual-axis inclining method. The dual-axis inclining method is an X-ray stress measurement technique using the iso-inclination method jointly with the side-inclination method. It is not possible to apply the conventional X-ray stress measurement method based upon the sin2ψ method to such measurement even if the irradiated area is at the neighborhood of the open-end of the hole. The dual-axis inclining method was described, and the analysis was made of the relation between the position of the irradiated area, the diameter of hole and the scannable angle range. On the assumption that the ψ angle should be scanned up to 30 deg for the stress measurement, the result of the analysis shows that the distance between the irradiated area and the open-end of the hole should be less than a quarter of the hole diameter. The experiment was conducted for a round pipe of carbon steel. It was found that even when the intensity of background decreased only on the lower side of diffraction peak due to the shielding by the side wall of the pipe, the circumferential stress can be evaluated by directly applying the parabola peak method or the 2/3-value breadth method to the collapsed diffraction profiles without processing the background.