ES291037A1 - Method and apparatus for controlling temperature of the workpiece during rolling - Google Patents

Abstract

A method of rolling a hot elongated workpiece in a rolling mill train comprises generating a signal representing a desired predetermined temperature for the workpiece, generating a second signal corresponding to the difference between the actual and desired temperature, and varying the speed of the train to vary the heat losses by conduction and radiation to maintain the workpiece temperature substantially at the desired value. An increase, for example, in the speed of the train results in less heat being lost by conduction and radiation, due to the shorter time available to the workpiece for losing heat, and an increased input of heat from the rolls as they roll the workpiece. The temperature of a strip S is measured by pyrometers 30, 31, and 32, whose outputs are fed into an analogue computer which controls the motors 21 of rolling stands 11-16 and also cold water sprays 27 and coiler motors 28. The speeds of the stands are controlled so that the strip temperatures measured by the pyrometers reach predetermined values. An X-ray thickness gauge 33 may be used to give automatic thickness control of the strip. The screwdown for the stands is by means of a motor-driven worm 39 and which actuated a screw 37, the worm being axially movable by a high-speed piston cylinder assembly 42. In order to permit coiling of the free end of the workpiece, the rolling speed of the train is gradually increased from a suitable value. Specifications 942,128 and 952,941 are referred to.