Surface Roughness Influence on MFL Inspection for Surface Defect

表面粗糙度對表面缺陷漏磁檢測的影響研究

楊芸(Yun Yang) ； 李龍(Long Li) ； 馮搏(Bo Feng) ； 康宜華(Yi-Hua Kang)

《先進工程學刊》 11卷2期 (2016/04) Pp. 63-66

摘要

漏磁檢測廣泛應用於鐵磁性材料的無損檢測與評估中，不同加工方法和使用環境會引起材料表面粗糙度（Ra）的差異，在漏磁檢測中，工件表面粗糙度為影響檢測信號的重要因素之一。本文結合自動化漏磁探傷設備，由實際工程測試結果分析，得知表面粗糙度對檢測結果有較大的影響。為了進一步探究，建立了簡化的工件表面粗糙度模型，採用ANSYS模擬分析了表面粗糙度引起的背景磁場及其對工件表面缺陷漏磁場信號分辨能力的影響，並提出了一種基於傳感器提離效應的粗糙表面缺陷信號信噪比改善方法。

關鍵字

漏磁探傷 ； 表面粗糙度（Ra） ； 表面缺陷 ； 模擬 ； 提離效應 ； 信噪比

並列摘要

Magnetic flux leakage (MFL) inspection technique is widely used in the inspection and evaluation of ferromagnetic materials. Different processing methods and application environment will cause the difference of material surface roughness (Ra) which becomes one of the key factors influencing the detection signal during MFL inspection. This paper analyzed the industrial testing results with automated MFL equipment and comes cautiously into a conclusion that surface roughness has a major influence on testing results. In order to further study the surface roughness influence on MFL detection, this paper established a simplified model of the workpiece surface roughness. ANSYS simulation was used to analyze the background magnetic field caused by surface roughness and its impact on the resolution capacity of leakage magnetic field of surface defect. Furthermore, a method to improve signal noise ratio (SNR) based on the lift-off effect of sensors on rough surfaces is proposed.

並列關鍵字

MFL inspection ； surface roughness (Ra) ； surface defect ； simulation ； lift-off effect ； SNR