The angle steel can be composed of various stress-bearing members according to the different needs of the structure, and can also be used as a connection between the members. Widely used in various building structures and engineering structures, such as building beams, bridges, power transmission towers, lifting and transporting machinery, ships, industrial furnaces, reaction towers, container racks, cable trench supports, power piping, busbar support installation, and warehouses Shelves and so on.
Angle steel is a carbon structural steel for construction. It is a section steel with a simple section. It is mainly used for metal components and the frame of factory buildings. In use, it requires good weldability, plastic deformation performance and certain mechanical strength. The raw material billets for the production of angle steel are low-carbon square billets, and the finished angle steel is delivered in a hot-rolled, normalized or hot-rolled state.
It is mainly divided into two types: equal angle steel and unequal angle steel. Among them, unequal angle steel can be divided into two types: equal thickness and unequal thickness.
The specifications of angle steel are expressed by the dimensions of side length and side thickness. At present, the domestic angle steel specifications are 2-20, and the number of centimeters on the side length is used as the number. The same horn steel often has 2-7 different side thicknesses. Imported angles indicate the actual size and thickness of both sides and indicate the relevant standards. Generally, those with a side length of 12.5cm or more are large angles, those with a side length between 12.5cm and 5cm are medium-sized angles, and those with a side length of 5cm or less are small angles.
The order of import and export angle steel is generally based on the specifications required in use, and the steel grade is the corresponding carbon steel grade. In addition to the specification number, the angle steel has no specific composition and performance series. The delivery length of angle steel is divided into two types: fixed-length and double-length. The range of fixed-length selection of domestic angle steel is 3-9m, 4-12m, 4-19m, 6-19m according to different specifications. The length of angle steel made in Japan is 6-15m.
The section height of the unequal angle steel is calculated according to the long side width of the unequal angle steel. Refers to steel with an angular cross section and unequal lengths on both sides. It is a kind of angle steel. Its side length ranges from 25mm×16mm to 200mm×l25mm. Rolled by a hot rolling mill.
The general specification of unequal angle steel is: ∟50*32–∟200*125, the thickness is 4-18mm.
Unequal angle steel is widely used in various metal structures, bridges, machinery manufacturing and shipbuilding, various building structures and engineering structures, such as building beams, bridges, power transmission towers, lifting and transporting machinery, ships, industrial furnaces, reaction towers, container racks, and warehouses, etc.
China’s import and export of angle steel each have a certain batch, mainly imported from Japan and Western Europe. Exports to regions are mainly Hong Kong, Macau, Southeast Asia, Latin America and Arab countries. The export production companies are mainly steel mills (rolling mills) in Liaoning, Hebei, Beijing, Shanghai, Tianjin and other provinces and cities.
The imported angle steel varieties are mostly large, small and special-shaped angle steels, and the export varieties are mostly medium-sized angle steels such as No. 6 and No. 7 and so on.
The surface quality of angle steel is stipulated in the standard, and it is generally required that there should be no harmful defects in use, such as delamination, scarring, and cracks.
The allowable range of angle steel geometric shape deviation is also stipulated in the standard, which generally includes items such as curvature, side width, side thickness, top angle, theoretical weight, etc., and stipulates that the angle steel must not be significantly twisted.
(1) Composition index: The chemical composition of angle steel belongs to the rolled steel series for general structure, and the main verification indexes are C, Mn, P, S. According to different grades, the content varies, the approximate range is C<0.22%, Mn: 0.30—0.65%, P<0.060%, S<0.060%.
(2) Inspection method: When testing the above chemical components, the commonly used standard inspection methods include GB223, JISG1211-1215, BS1837, BS Manual 19, GOST 22536, etc.
GB/T2101-2008 (General requirements for section steel acceptance, packaging, marking and quality certificate);
GB/T706-2008 (replace GB/T9787-88 GB/T9788-88) (hot-rolled equilateral/unequilateral angle steel size, shape, weight and allowable deviation);
JISG3192-94 (shape, size, weight and tolerance of hot rolled section steel);
DIN17100-80 (quality standard for ordinary structural steel);
ГОСТ535-88 (Technical conditions for ordinary carbon steel).
According to the provisions of the above-mentioned standards, the angle steel should be delivered in bundles, the number of bundles, and the length of the same bundle should comply with the regulations. Angle steel is generally delivered naked, and it is necessary to pay attention to moisture-proof during transportation and storage.
(1) Inspection method:
① Tensile test method. Commonly used standard inspection methods are GB/T228-87, JISZ2201, JISZ2241, ASTMA370, ГОСТ1497, BS18, DIN50145, etc.;
② Bend test method. Commonly used standard inspection methods are GB/T232-88, JISZ2204, JISZ2248, ASTME290, ГОСТ14019, DIN50111, etc.
(2) Performance indicators: The inspection items for evaluating the performance of angle steel are mainly tensile test and bending test. The indicators include yield point, tensile strength, elongation and bending qualification.
Weight per meter = 0.00785 * (side width + side width-side thickness) * side thickness
For example, 50*5 angle steel: (50+50-5)*5*0.00785=3.73 (this algorithm can only roughly calculate the weight of the angle steel, the actual hardware manual shall prevail!)
It is mainly divided into equilateral angle steel and unequal angle steel. Unequal angle steel can be divided into unequal edge equal thickness and unequal edge unequal thickness. The two sides of equilateral angle steel are equal in width. Its specification is based on the side width × Edge width × The edge thickness is expressed in millimeters. Such as “∟ 30” × thirty × 3 “, i.e. equilateral angle steel with side width of 30mm and side thickness of 3mm. It can also be expressed by model, which is the centimeter of side width, such as ∟ 3#. The model does not represent the dimensions of different edge thicknesses in the same model. Therefore, the edge width and edge thickness of angle steel shall be filled in completely in the contract and other documents to avoid being represented by the model alone. The specification of hot rolled equilateral angle steel is 2#-20#. Angle steel can form various stress components according to different structural needs, and can also be used as connectors between components.
The section height of unequal angle steel is calculated according to the length and width of unequal angle steel. It refers to steel with angular section and unequal length on both sides. It is one of the angle steel. Its side length is 25mm × 16mm～200mm × l25mm。 It is rolled by hot rolling mill. The specification of general unequal angle steel is: ∟ 50 * 32 — ∟ 200 * 125, and the thickness is 4-18mm.
Unequal angle steel is widely used in various metal structures, bridges, machinery manufacturing and shipbuilding, various building structures and engineering structures, such as house beams, bridges, transmission towers, hoisting and transportation machinery, ships, industrial furnaces, reaction towers, container racks and warehouses.