A manufacturing method of a seamless metal pipe includes determining whether a preceding-stage stand group is used in outer diameter reduction or in thickness reduction of a hollow shell; and performing elongating on the hollow shell, into which a mandrel bar is inserted, based on the determination. In addition, in the elongating, when the preceding-stage stand group is used in the outer diameter reduction, the hollow shell is rolled in a state where an inner surface of the hollow shell does not come into contact with the mandrel bar in the preceding-stage stand group, and the hollow shell is rolled in a state where the inner surface of the hollow shell comes into contact with the mandrel bar in the succeeding-stage stand group.

A process for thin strip production integrates continuous casting and rolling, with steps including continuous casting, rough rolling, induction heating, finish rolling, laminar cooling, high-speed shearing, and coiling. A key feature is the in-line heating between casting and rough rolling, where wide surfaces, narrow surfaces, and corners of the casting blank are heated simultaneously. This process improves rough rolling efficiency, enhances uniformity and thickness stability of thin strips, reduces out-of-tolerance rates, and minimizes rolling-induced cracks.

An electrode rolling device acquires thicknesses of an electrode sheet, Tc at a center portion in a width direction, Twe at an end portion on a first side, Tde at an end portion on a second side, Twc at a first intermediate portion, which is set between the center portion and the end portion on the first side, and Tdc at a second intermediate portion, which is set between the center portion and the end portion on the second side. The electrode rolling device determines a deviation Twe between the thickness Tc and Twe, a deviation Twc between the thickness Tc and Twc, a deviation Tde between the thickness Tc and Tde, and a deviation Tdc between the thickness Tc and Tdc, and performs control so as to reduce the deviation Twe or Twc, whichever is larger, and to reduce the deviation Tde or Tdc, whichever is larger.

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 method for producing an ultra-thin strip of less than 0.8 mm from cast steel in batch/continuous operation with a casting-rolling system. The method includes casting a thin slab having a casting thickness of 90-150 mm and width of at least 1000 mm at a casting speed of 7 m/min. The thin slab is heated/homogenized to a first temperature in a continuous furnace and subsequently rolled by at least seven final roll stands into an ultra-thin band. Neither the thin slab nor strip undergo inductive heating during production. The thin slab rolling steps include rough rolling the thin slab at the heated/homogenized first temperature by a roughing stand; heating/homogenizing the rough-rolled thin slab to a second temperature by a further continuous furnace; and finally rolling the rough-rolled thin slab at the second temperature to the ultra-thin strip by the final roll stands arranged downstream of the further continuous furnace.

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.