Measurement of residual stress of steel filaments by using focused ion beam and digital image correlation

집속 이온빔과 디지털 화상 관련법를 이용한 고 탄소 미세 강선의 잔류 응력 측정

The residual stress in axial stress in the axial direction of the steel filaments has been measured by using a method based on the combination of the focused ion beam (FIB) and high resolution strain mapping program (VIC-2D). That is, the residual stress was calculated from the measured displacement field before and after the introduction of a slot along the steel filaments. The displacement was obtained by the digital correlation analysis of high-resolution scanning electron micrographs, while the slot was introduced by FIB milling with low energy beam. The present measurement revealed that the residual stress within 8% of the magnitude was persistent in the steel filaments fabricated.