What is cold rolled steel strip

Cold rolled steel strip and sheet is generally 0.1 ~ 3mm thick, width of 100 ~ 2000mm; are hot rolled steel strip or steel plate as raw material, at room temperature by the cold rolling mill rolled into material. Cold rolled steel strip and sheet has a clean surface, flat, high dimensional accuracy and good mechanical properties and other advantages, most of the products into the volume, and a large part of the processed into coated steel plate factory. Rolled cold rolled sheet production efficiency, easy to use, conducive to subsequent processing. Therefore, widely used, has gradually replaced the same thickness of hot rolled sheet. Only a small number of special-purpose cold rolled alloy steel plate to take a single piece of rolling. Cold rolled steel strip and plate production in industrially developed countries has accounted for about 30% of total steel production. In addition to ordinary carbon steel, there are silicon steel, stainless steel and alloy structural steel.

In 1553 the French Brulier (Brulier) made a rolling mill, rolling minting gold and silver plate. Early cold rolling mill is a two-roll type, the later use of work roll roll diameter is smaller and more rigid four-roll mill. In order to roll thinner and harder strip, and the development of the work roll roll diameter smaller and more rigid six-roll, twelve-roll, twenty-roll and partial eight-roll (M.K.W. type) and other mills.

Single piece rolling without tension, rolled products thicker (> 1mm), lower speed (< 2m / s), only for the production of a small number of special-purpose steel plate.

Cold rolled strip steel production is rolled in coils, using tension coiling and uncoiling devices, high speed (up to 42m/s), road compression rate is large, the plate shape is flat and straight. The mill has a single reversible and continuous two types.

Single-stand reversible four-roll cold rolling mill is suitable for the production of many varieties, small batches, thickness of 0.2mm above the ordinary carbon steel or low alloy steel. Rolling silicon steel, stainless steel and other high-alloy special steel more than twenty rolls or partial eight-roll mill.

Continuous rolling mill consists of 3 to 6 racks. The more the number of racks, the greater the total compression rate, the product thickness is thin; the faster the rolling speed, the greater the output; applicable to the production of large, small varieties of specifications of ordinary carbon steel automotive plate, galvanised plate, tin plate, and so on.

Full continuous cold rolled strip mill in the 70's has developed a small number of full continuous cold rolling mill, strip rolls in the mill before entering the former end of a coil with the latter coil head welding, the use of live sleeve storage of sufficient strip to ensure that the welded mill still continue to roll. Rolling process controlled by computer, in the dynamic can change the specification. After rolling by the flying shear cut off, sub-roll. Full-continuous rolling mill rolling each coil of strip without the need to wear the strip and tailing, saving the gap time for volume change. The annual production capacity of each fully continuous mill is up to 2 million tonnes. Eliminate the coil head and tail thickness out of tolerance of the scrap, improve the strip rolling accuracy and yield. Cold rolled strip mill status quo in 1980, the world's roll length greater than 860mm strip steel cold rolling mill a total of 466 units, of which 161 reversible four-roll mill, reversible multi-roll mill 108 units, 197 units of continuous rolling mill. China has a wide strip steel cold rolling mill 9, of which four reversible four-roll mill, reversible twenty-roll mill 3, partial eight-roll mill 1, a continuous mill