Development and Practicing of Automatic Fluorescent Magnetic Particles Inspection

The fluorescent magnetic particle inspection is widely used as a visual inspection method for checking cracks generated in hardening and grinding of induction-hardened parts.

However, automation of this inspection process has strongly been demanded, due to poor environmental conditions and production line speed.

To satisfy such a demand, we have developed a method for picking up images of automotive parts with higher S/N ratio and an original algorithm for image processing which helps measure cracks accurately without being affected by the illuminance and magnetic particle solution concentration.

Then we selected the front axle shaft as the object to study practical use and have solved various technical problems in actual use, thereby succeeding in actual application to our production lines.