Cold-rolled steel: characteristics, features, application

Cold-rolled steel (h / k) - one of the most popular types of modern metal. In the total amount of steel produced, the sheet thickness is continuously increased. It is made, as can be understood from the name, by the method of cold rolling. Plastic metal is treated with a special method by pressure without preheating. Produced in two forms - a sheet of cold-rolled and in rolls. Finished products can be of different lengths and sizes, with edged edges, with compression.

Characteristics of cold-rolled steel

The growing demand for cold-rolled steel is explained by higher quality characteristics than in hot-rolled products. In addition, the production of sheet metal thickness of 1 mm or less is economically feasible only in a cold way. Cold rolling is subjected to conventional carbonaceous, high-quality carbonaceous, alloyed and high-alloy steels, corrosion-resistant, heat-resistant and heat-resistant alloys. The chemical composition of the processed steel determines the properties of the resulting rolled metal and, to a certain extent, its application area. So, for complex stamped products low-carbon steel sheet cold rolled, GOST 19904-90 is used. The microstructure of the metal after rolling largely determines its plasticity, other things being equal.

Cold-rolled steel is produced in the thickness of 0.25-5.0 mm and is supplied in sheets of different sizes - from 510x710 mm to 1250x2500 mm. Steel thickness of 0,25-2 mm can be supplied galvanized. Cold-rolled sheet steel transformer produced thickness of 0.28-0.5 mm, sheet dimensions 750-1000 mm. Important requirements are imposed on transformer steel, namely, the magnitude of the magnetic induction and the size of the watt loss. Manufacture of sheet and rolled cold-rolled steel from structural steels alloyed with high-quality structural steels for special purposes, electrotechnical low-carbon and siliceous steels. A cold-rolled tape is spring-loaded, instrumental, for magnetic circuits.

Features of cold-rolled sheet

The cold-rolled sheet of general purpose is made of steel grades, the chemical composition of which is determined by GOST 1050-88: 08ps, 08kp, 10kp, 10ps, 15ps, 15kp, 20ps, 20kp, 25, 30, 35, 40, 45. For cold stamping, Steel grades 08yu, 08kp and 08ps. The surface of cold-rolled steel is smoother, and the geometric shapes are more accurate.

Contrary to its name, cold-rolled steel does not avoid heat treatment. Any cold-rolled metal is produced from a hot-rolled billet.

Cold-rolled steel production

Cold-rolled sheet is made in two ways: polistnym or roll. In a polished process, the hot-rolled steel produced in the roll after cold rolling is cut into sheets that are already individually sent for further processing (annealing, straightening, etc.).

In modern production preference is given to the roll method. In this case, all the stages of production of cotton steel are carried out in rolls and already finished products are manually or automatically cut into sheets. The roll method makes it possible to automate the bulk of technological operations, increases the yield of finished products, improves the properties and shape of the metal due to the stability of the production process. With this method, an increase in the output of finished products is possible in the same areas. In some cases, cold-rolled steel is supplied in rolls. Depending on the technological process of some machine-building enterprises, this reduces the amount of waste. In the production of cold-rolled steel, compulsory operations are the cleaning of hot-rolled strip from scale, rolling on mills (reversible or continuous), heat treatment, cutting, straightening.

Distinctive features of hot-rolled and cold-rolled products

Hot-rolled metal is easier to process. For products manufactured by the hot rolling method, low-grade, lower-cost steel is more often used. Finished products are often coated with scale and require additional processing. Since it is impossible to calculate the limits of metal deformation during cooling, the geometry of hot-rolled metal does not differ rigorously (uneven thickness, unevenness at the edges and corners).

Cold-rolled rolling method makes it possible to more accurately withstand the required dimensions of products. The surface of such rolled products is smoother, the thickness is uniform, so the final processing of the product is minimized, and sometimes it is not even required. Due to the homogeneous structure, the cold-rolled metal is more durable and has better characteristics for tearing, bending, stretching. For production, high-grade steel is used.

Application of cold rolled steel

Cold rolled metal is used in many industries: in the automotive industry for bodywork, for machine housings, production devices, machine parts, in construction, processing industry, and the production of household appliances.

Quiet steel 3 cold-rolled - one of the most expensive in value. The minimum oxygen content helps to increase the homogeneity of the structure, plasticity and resistance to corrosion. Used for rigid steel structures and load-bearing elements, shaped rolled products, pipeline fittings. Cold-rolled steel is used in the manufacture of parts subjected to thermal and chemical effects.