Nodestructive microwaves methods for detection of micro-cracks on stainless steels

Abstract

The aim of this study is the presentation of a new non-destructive testing technique on stainless steels by the near field using microwave devices. This technique will allow the detection of micro-cracks in the surface of stainless steels. We will be using for this purpose a microstrip antenna characterized by a resonance frequency of 8 GHz. The simulation software High Frequency Structure Simulator (HFSS) will be used for the calculation of the variation in the resonance frequency and reflection coefficient that caused by the defect. This defect is assimilated to a rectangular groove. The obtained results are very interesting because we arrived to detect a crack depth less than 20 μm. Furthermore, industrial ultrasonic testing methods do not always detect satisfactorily defects of small depth (less than 5 mm) located near the inspection surface