Prodn. of billets for hot-rolling installations - by cutting a cast pipe-length into a helical ribbon and then straightening

摘要

Mfr. of billets for hot-rolling mills consists of cutting a cast pipe length into a helical ribbon and straightening the part of ribbon thus sepd. to form a billet for a subsequent rolling process. The installation for billet mfr. consists of a casting ladle, one or several centrifugal casting machines with extraction mechanisms, a furnace for temp. maintenance, shears, a machining installation for surface treatment, a straightening unit, a reheating furnace, a descaling installation and measurement/check installation arranged in series. Pref. the furnace for temp. maintenance is combined directly with a loading mechanism and a rotary-blade shear unit. The speed of the associated skew transport rolls is adjustable. The top and bottom elements of the shear unit have separate drives. Furthermore, the shear unit can be swivelled on its base, and the shaft positions of its top and bottom elements can be altered. The pipe length serving as the preliminary billet material is characterised by the fact that its wall thickness at the start position of the ribbon sepn. cut is reduced in comparison with the rest of its wall thickness. USE/ADVANTAGE - Can be used in fine steel and wire rolling mills. It eliminates the need for costly welding processes used sometimes to produce long billets. It also eliminated the need for long furnaces used with other installations for billet temp. maintenance.