Hot billet surface inspection

Challenge Details

Billets are produced from a Continuous Casting Machine (CCM) with dimensions of 150x150 mm. These raw billets are then sent to the rolling mill for further processing into wire rods, round bars, and deform bars. Wire products require high-quality billets. Surface defects on billets can lead to problems during rolling. After cleaning the scale from the billet surface using a shot blast machine, operators inspect the billet surface. However, this inspection process requires the billet to be at room temperature. If defects are detected, the billet undergoes manual grinding to remove them. The current process takes around 3 days, and approximately 25% of the total billets need grinding. 

To reduce the overall timeline of 3 days the operator tries to inspect the surface of billet during casting however the billet cannot be inspected due to red hot temperature around 600-degree C. Automated visual inspection was attempted but failed due to difficulty in capturing clear images of red-hot surface. Some of the constraints which must be taken care of during installing any inspection system are: Limited space for additional machinery, heat management, and the need to integrate with existing continuous casting and rolling processes.

We are looking for a robust inspection system which has high accuracy in detecting surface defects on red hot billets.