Sumy bent steel corner, channel bending, sheet bending, strip steel cutting, sheet metal 9XS, U8A, 10HSND, 65G, 60S2A, 30HGSA, 12X1MF, HVG, st20, 40X, st45, 12X17
A bent steel corner is not the most popular, but still a fairly popular type of rolled metal, which is used in various directions. About where exactly it is used, due to what it is valued, how and according to what state standards it is produced, we will tell today.
A steel corner is one of the varieties of shaped metal products, which has an L-shaped cross section. A bent corner is only one of two varieties of this rolled product, the second is a hot-rolled corner.
It got its name because of the production method - it is produced by cold longitudinal bending of a steel strip on a roll forming mill. Hot or cold rolled sheet steel can be used as raw material. With this method, residual stresses remain at the bend, which have a negative effect on strength.
It is quite easy to visually distinguish a bent steel corner from a hot-rolled one: the first has a clear right angle, on the second the angle is smoothed, since it is impossible to give the metal a clear outline without additional heating.
Bent steel corner: GOST, types, application
Various steels can be used as raw materials:
structural quality - the main material for the production of rolled products for various needs,
low-alloyed - for the production of products that will be operated under static loads and low temperatures,
corrosion-resistant - for the production of rolled products, when using which resistance to water, steam or chemical compounds is important.
Types, GOST, assortment
The bent steel angle GOST 19771 and GOST 19772 are regulated. The standards respectively refer to the production of two main types of rolled products:
equal-shelf angle - the width of both planes is the same,
unequal - one of the shelves is wider than the other.
An additional division is made according to the accuracy of rolling, it can be:
high - marking "A",
elevated - "B",
normal - "B".
In the assortment of the equal angle angle, the key characteristics are:
shelf width: according to the standard, it can take values from 36 to 160 mm;
shelf thickness: from 2.5 to 4 mm.
With the release of unequal rolled products, one more is added to them:
width of the larger shelf: from 32 to 155 mm;
width of the smaller shelf: from 25 to 100 mm;
thickness: from 2 to 6 mm.
The indicators of permissible length for both varieties are the same and range from 3 to 12 m.
Cold-rolled steel is significantly inferior to hot-rolled steel in strength, therefore, it cannot be used in the installation of critical, highly loaded metal structures. However, cold bending makes it possible to obtain much more accurate dimensions, which in a number of situations is a critical requirement.
Despite the above disadvantage, the list of uses remains quite impressive:
mechanical engineering and machine building,
wagon building,
production of large-sized equipment,
furniture manufacture,
construction, architecture, design,
finishing facilities,
installation of frames that do not involve serious loads,
use in various reinforced concrete structures.
An additional advantage when using a steel bent corner is the ease of installation. Depending on the steel used, welding can be used, and if it is not possible, a bolted connection, which even a non-professional can perform with high quality.
Features of bent corners with unequal shelves
The range of these products is regulated in accordance with the norms and regulations of GOST 19772-93. The length of the blanks varies from 3 to 12 m. According to the accuracy, the profiling of the product is classified into products of ordinary, increased and high accuracy.
Corners with unequal shelves are not used for the manufacture of structures subjected to increased loads. Products are used for:
finishing works;
production of household appliances;
production of furniture designs;
implementation of architectural and design solutions.
Due to high performance and relatively affordable cost, corner metal is in demand in industrial and private construction.
The bent corner can be produced from cold-rolled or hot-rolled strip without its preheating. As a result, the weakest point of such products is the interface between two flanges, which is an increased stress concentrator and, accordingly, a likely place for cracks to appear under high loads.
Hot-rolled angle during the production process is under significant pressure from the rolling rolls. In combination with heating and high compression, this technological option allows you to evenly grind the grain and reduce the likelihood of cracking in the area of the mating shelves. Therefore, this type of product is preferable when performing critical work. Otherwise, both variants of the producttions remain practically equivalent building materials and semi-finished products for mechanical engineering.
The presence of an L-shaped profile provides high rigidity of the unequal angle and resistance to bending loads. In combination with high technological properties (good weldability for a wide range of steel grades, the ability to cut in different ways, fastening with bolts, rivets, etc.), this has led to a significant spread of angle profiles in the following areas:
civil, infrastructure, industrial construction (construction of frame structures, welding or assembly of fences, supports, beams, column branches and other elements, concrete reinforcement);
mechanical engineering (manufacturing of equipment cases, household appliances, car parts, ships, wagons, stiffeners, stops, racks, etc.);
bridge building;
furniture manufacturing;
production of embedded parts of reinforced concrete products and reinforced concrete structures.
Hot rolled metal angle is produced by rolling an ingot through a rotating shaft of a certain size. After that, the product is passed through a special rolling mill. This manufacturing method provides the product with the ability to withstand heavy loads due to its high strength and integrity. Due to their high strength, hot-rolled products are used to create reliable frames. Hot-rolled angle bars are made from ordinary carbon steel grade St3, various degrees of deoxidation, as well as low-alloy steel grades 09G2S, 10KhSND, and are regulated in accordance with GOST 8509-93 and GOST 8510-86.
Cold-rolled angle is made by bending a steel strip on special roll forming machines. Sizes are not strictly regulated, so you can choose the option you need. Such a corner does not have high strength, therefore it is mainly used for decoration and decorative elements, for the manufacture of metal products, and also as a fastener during construction work. Such rolled metal cannot be used in load-bearing structures. I have long been convinced of this on my own experience of construction work.
Equal-shelf. Complies with GOST 8509-93 standards. The width of the shelves for such a product will be the same. Such a product is characterized by high strength, since the stiffener is better able to withstand heavy loads.
Unequal. Complies with GOST 8510-93 standards. The width of the shelves is different. Such rolled products are inferior in strength, but necessary for certain structures, for example, I often use such material when reinforcing the foundation.
Steel angles are used in various industries and construction:
In the manufacture of metal structures and fasteners for cables, pipes, equipment, etc.;
As a supporting structure for power transmission racks;
When erecting reinforced concrete load-bearing structures as a reinforcing element for walls and ceilings;
In the arrangement of window and door openings;
When forming external right angles and framing arches;
In mechanical engineering and in the production of large-sized equipment, such as cranes;
In the furniture industry when forming a furniture frame;
Steel corners are covered with various protective anti-corrosion coatings, which allows them to be used in various aggressive conditions. As special coatings, my team uses a polymer film, galvanization and powder coating technology that is resistant to mechanical stress.
In addition to the main division according to the standard sizes and the manufacturing method given above, steel angles are also divided according to their purpose and the corresponding alloys from which they are made. This, of course, significantly expands the overall range of steel angles, but already based on these criteria.
Each type, determined by the purpose of the corner, is subject to its own separate GOST, which contains the technical conditions for the manufacture of metal products. That is, the steel grades used for the production of this particular type of rolled products, its classification and requirements for quality, strength and other properties and parameters of the finished product are indicated. Moreover, these GOSTs of technical conditions apply not only to corners, but also to other steel products. The latter already depends on the type of metal products, which is covered by the specification standard.
So, all steel angles (both hot-rolled and bent), that is, produced according to the previously listed GOST 8509, 8510, 19771, 19772 and ISO 657-1, 657-2, are manufactured according to their intended purpose in the following types and according to the relevant standards:
corners for building and other steel structures assembled (erected) with welded and other joints, as well as for other purposes - are produced in accordance with GOST 27772-2015;
increased strength corners made of non-alloyed high-quality and low-alloyed steels used in products and used for riveted, welded or bolted steel structures - GOST 19281-2014.
And hot-rolled products of an angular profile (GOST 8509, 8510 and ISO 657-1, 657-2) are also madeand the following types according to relevant standards:
corners for special and general use, made from carbon steel of ordinary quality - produced in accordance with GOST 535-2005;
corners for shipbuilding, made from steel alloys with normal and increased strength characteristics - GOST 5521-93;
angular profile products from low-alloy structural steel alloys used for the manufacture of various bridge structures erected in normal and northern climatic conditions - GOST 6713-91;
corners made from steel alloys with normal, high, and increased strength characteristics and used for the construction of sea and river vessels, berths, oil and gas platforms, pontoons, as well as other structures with welded joints (including those intended for operation in arctic conditions ) - GOST R 52927-2015;
angular profile products made of structural alloyed steel alloys used for the manufacture of structures of road, rail, as well as combined and separate urban and pedestrian bridges intended for operation in extreme climatic conditions (northern regions and zones with maximum seismicity) - GOST R 55374-2012.
