A system for maintaining a continuous speed in a long rolling mill is provided that includes a plurality of guide rollers that feed a billet product from a caster to an entry roll stand along a mill pass line to an exit roll stand. Also, the system includes a plurality of gauges positioned at a plurality of locations along the mill pass line, the gauges perform speed measurement of the billet product passing along the guide rollers. Furthermore, the system includes a logic controller that receives the speed measurement and maintains a speed relationship where the speed between the caster and the entry roll stand is constant as well as the exit speed of the end roll stand is also constant.

Before a first strip point is fed into a production line, an actual energy content at a location in front of the production line and a setpoint energy content at a location behind the production line are received for a first strip point, second strip point, and third strip point. The third strip point, followed by the first strip point, followed by the second strip point, are fed into the production line. A command variable for the first strip point and second strip point(s) is determined prior to feeding in the first strip point. Each command variable is determined based on (a) the actual value and the setpoint value of the strip point currently entering the production line, and (b) the actual value and the setpoint value of at least one strip point having already entered.

A method controls the section sizes of a rolled product in a segment of a rolling line between at least two rolling stands, wherein each is provided with its own drive members, in which at least a detector located between the two rolling stands detects a characteristic size of the rolled product. A control unit compares the characteristic size of the rolled product with a reference size and acts on said drive members in order to hold the rolled product in an optimal drawing condition. The method includes setting a predefined value of an electric quantity of at least one of the drive members, measuring the reference size, and verifying the characteristic size of the rolled product in transit. If a deviation is detected between the characteristic size and the reference size, returning the characteristic size of the rolled product to the reference size.

The present application provides an extra-thick Q500qE bridge steel plate and a production method therefor. The production method involves direct rolling of the slab after three-stage heating before rolling and three-stage cooling of the steel plate after rolling. This method can produce a Q500qE steel plate with a maximum thickness of 150 mm, which meets the Z35 level Z-direction tensile performance requirements and the nondestructive testing requirements of Grade II or above according to GB/T 2970-2016 standard. The production process is simple, efficient, and cost-effective.

A roll stand of a rolling mill is supplied with a metal strip by an upstream supply device at an in-feed speed (v), with said metal strip being rolled in the roll stand. A measuring device between the supply device and the roll stand detects a respective thickness value (d) of the metal strip for consecutive sections of the metal strip and supplies said value to a control device of the rolling mill. The control device determines final thickness deviations based on the preliminary thickness deviations. The control device determines a respective control value (A2, A3) for the roll stand and/or the supply device for the sections of the metal strip based on the final thickness deviation of the respective section of the metal strip and the final thickness deviations of multiple preceding and/or subsequent sections of the metal strip.