Method of operating a wide band hot rolling mill

Claim 1

In a process which includes operation of a wide band, hot rolling mill line in which a band of metal at an elevated temperature is produced from a slab of metal at an elevated temperature after the slab is passed from a furnace by passing the slab along a straight line of travel through a multiple stand roughing section and then through a multiple stand finishing section, the improvement characterized by performing the following steps upon occurrence of a malfunction in the process: preserving the condition of a band during down time of the process upon occurrence of a malfunction by performing the following steps: lifting the trailing edge of the band from the roughing section at a location upstream from a final roughing stand of said roughing section; winding the band, trailing edge first, and in a reverse rolling direction along said travel line about a transverse horizontal axis above said travel line of said roughing section to form a coil of the band and thus remove the band from said travel line; maintaining the formed coil at an elevated temperature during the down time by rotating the coil with respect to spaced heaters; and, preserving the condition of a slab during down time of the process by performing the following steps upon occurrence of a malfunction: moving the slab laterally in a horiztontal direction out of the line of travel to remove the slab from the roughing section at a location upstream of the horizontal axis about which the band is wound; maintaining the slab at an elevated temperature by reciprocating the slab relative to spaced heaters; and returning to the line any band or slab removed from the line after correcting the malfunction whereby processing of the band or slab is continued without degradation thereof due to the malfunction.