![]() It is generally available in coiled form in widths from 900 to 1,800mm.Ī roughing stand reduces the continuously cast slab to an intermediate size by a series of reversing end-to-end passes through the mill. The typical thickness used in construction is 0.4 to 3.2mm. The most common form of strip steel used in construction is hot-dip galvanized coil. Strip steel is used to produce many different products and in many applications. Steel plate is commonly used in many different and demanding applications including: Plates with a nominal yield strength 275MPa or 355MPa, commonly used in construction, can be supplied in either the As Rolled, Normalised (N) or Normalised Rolled (NR) condition, and are rolled from continuously-cast slab.Ĭlose control of chemical composition is maintained to produce clean steels with consistent strength and toughness properties that meet all relevant national standards, as with all structural products, and state-of-the art levellers produce flat plates with controlled residual stress. Normal plate sizes range from 5mm to 200mm thick, with widths up to 3.5m and lengths up to 18.0m. For use in building construction plate will normally be welded into fabricated sections. Plates are available in a wide range of grades and sizes. The figure shows the stand in a universal mill used to create open sections. In a universal mill the stands contain both vertical and horizontal rolls and the hot steel passes backwards and forwards through the same mill multiple times with the shape being formed by reducing the gap between rolls on successive passes. ![]() ![]() The product passes through each roll gap only once. In a structural mill there are multiple stands each containing specially shaped rolls where the full set of rolls gradually shape the hot steel in successive passes through separate roll gaps. These work rolls that contact the hot steel are often supported by larger diameter rolls to prevent them bending under the rolling loads to ensure a uniform thickness product.įor long products there are two types of mills structural and universal. Two main classes of product are produced - flat products such as plates, sheets or strips of uniform thickness, and long products which are lengths of a particular cross section, ranging from rectangular bars to double flange H sections.įor flat products, two horizontal rolls are set one above the other in an open housing. To change the shape of a material as strong as steel the rolls must exert forces measured in hundreds of tonnes, and must also draw the steel continuously through the rolls while reducing the thickness. Rolls are arranged in pairs, either just horizontally or both horizontally and vertically, and housed in a 'stand'. The method that is most commonly used for shaping is to heat the steel to around 1,280☌ in a reheat furnace and then roll the steel, squeezing it between sets of rolls. For that reason the billets, blooms, beam blanks and slabs from the steelmaking process are shaped into basic products at carefully controlled elevated temperatures. Steel is a strong material that is highly resistant to shaping at normal temperatures but this resistance lessens considerably at higher temperatures.
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