논문 상세보기
pp.54-62
The most comprehensive and particularly reliable method for non-destructively measuring the residual stress of the surface layer of metals is the sin method. When X-rays were used the relationship of sin measured on the surface layer of the processing metal did not show linearity when the sin method was used. In this case, since the effective penetration depth changes according to the changing direction of the incident X-ray, becomes a sin function. Since cannot be used as a constant, the relationship in sin cannot be linear. Therefore, in this paper, the orthogonal function method according to Warren’s diffraction theory and the basic profile of normal distribution were synthesized, and the X-ray diffraction profile was calculated and reviewed when there was a linear strain (stress) gradient on the surface. When there is a strain gradient, the X-ray diffraction profile becomes asymmetric, and as a result, the peak position, the position of half-maximum, and the centroid position show different values. The difference between the peak position and the centroid position appeared more clearly as the strain (stress) gradient became larger, and the basic profile width was smaller. The weighted average strain enables stress analysis when there is a strain (stress) gradient, based on the strain value corresponding to the centroid position of the diffracted X-rays. At the 1/5 max height of X-ray diffraction, the position where the diffracted X-ray is divided into two by drawing a straight line parallel to the background, corresponds approximately to the centroid position.
1. 서 론
2. 회절강도 분포곡선 해석
3. 가중평균해석법
3.1. 가중평균변형률
3.2. 가중평균변형률과 회절선위치의 특성값과의관계
4. 회절강도 분포곡선의 계산결과와 sin 다이어그램
4.1. 계산조건
4.2. 변형률구배가 있을 때의 회절강도 분포곡선과sin 다이어그램
5. 정규 분포된 기본프로파일(principle profile)중첩을 이용한 회절다이어그램의 시뮬레이션
5.1. 중심위치 결정방법
5.2. sin 다이어그램과 응력인자 평가
6. 결 론
References
