形鋼用熱間表面疵検出システムの開発

抄録

The steel making industries have been requiring for high speed and continuous making processes, and improving quality assurance for the products. Although rolling process have developed automated system, after rolling-treatment have not automated satisfactory in steel making processes. Because of difficulty to automate for detecting of the surface defects, measuring the size, measuring strengh of the products. But in recent progress, they have developed for automated procedure. But almost inspection of surface defects are assured by human visual inspection. This paper described about an inspection of surface defects for large section products (ie, wide flange beam, I shaped beam, sheet pile etc.) after rolling hot products. This system applied detecting temperature deviation produced by defect. The wavelength of detector is maximized to obtain the signal to noise ratio. The special designed optical attenuators, which composed simple shaped slits, have developed to compensate the peculiar temperature pattern due to the shape of cross section. The attenuators are located in the optical pathes between speciemen and the lens of ITV camera. The image processor takes only 66 milli seconds per frame to pick up the defect information in the obtained image.