Steel Wire Mill - Annealing Process Control
Many steel wire mills have production organized in similar steps: reheating of steel billets is followed by wire shaping in a set of consequent mill stands starting with roughing mill stands, followed by intermediate mill stands, and various finishing mill stands depending on target products.
In this example, one of the products was high quality steel wire used in car manufacturing, which required a very demanding and well controlled annealing process. Material throughput is high, and speed of material in the process changes from the few meters per minute in the roughing mill, and as material thickness decreases, speed at finishing sections can be more than several hundred meters per minute, it was of paramount importance to provide correct material type, dimensions and temperature just before it enters annealing process.
This was achieved by assigning temperatures readings at the various places in the mill to the particular longitudinal position of the material, tracking of all material in the process, and with continuous supply of annealing process in just in time manner with values acquired in previous process steps, combined with information from ERP.