二次元検出器走査システムによるショットピーニング材表層近傍応力分布測定

Stress distribution measurement near the surface in shot peened material using two dimensional detector

Zhang, S.; 菖蒲 敬久  ; 城 鮎美

Zhang, S.; Shobu, Takahisa; Shiro, Ayumi

二次元検出器(PILATUS)走査システムを開発した。このシステムを利用し、高精度な回折角と広い逆格子空間が測定できる。高エネルギー放射光単色X線を用いて、反射法で各回折面の回折リングを測定した。異なる回折面のX線の有効侵入深さを考慮したうえで、X線応力測定算出し、ショットピーニング試験片深さ方向の応力分布の評価を行った。

Recently, stress/strain measurements by high energy synchrotron X-ray diffraction has been paid to attention because a minute area in the material can be measured. In addition, evaluation of stress/strain in material using two-dimensional detectors, such as IP, CCD and PILATUS, has dramatically increased due to the advances in detector technology. Especially, the PILATUS detector is expected to be used for various stress/strain measurements because it has a lot of features which are wide dynamic range, low noise and high flame rate. But this detector is unsuitable for stress/strain measurement in usual use because it has handicap that effective area is small and pixel size is large (0.172 micrometer) compared with that of CCD or IP. In this study, we has been developed a large area detector system by using scanning the PILATUS-100 K detector on the x-y stages. Using this system, we succeeded to measure a wide reciprocal lattice space with high angular resolution. Though the distance from this sample to PILATUS detector was almost 1m, a lot of diffraction rings were measured with high angular resolution less than 0.01 degree. Also using these diffraction rings, we succeeded the development of the correction program for this scanning system in order to obtain high quality data. Now we try to calibrate stress distribution to the depth direction in steel materials with residual stress by pseudo 2theta-sin2psi method using some diffraction rings which was measured by a reflection method. In this presentation, this result will be informed and discussed.