Low-carbon steel used in construction is an iron alloy with a content of up to 2% carbon and other elements, obtained as a result of a two-stage production process. In the first stage of production, iron ore melted in blast furnaces is used to obtain pig iron containing iron, 2,5-4,5% coal and about 7% other admixtures. In the second stage, the pig iron is subjected to an oxidation process, as a result of which steel with the required chemical composition is obtained.

Cast iron is a melted pig iron with the addition of scrap metal. Contains 2-4% coal and up to 4% silicon.

Steel is a melted deoxidized pig iron. Includes up to 2% Carbon. Depending on the application, steel is divided into: Construction, tool and special.

Division of steel according to chemical composition:

• Carbon steel (non-alloy) – The main ingredient in addition to iron, is coal (into 2%), and the content of other ingredients (silicon, mangan, phosphorus, sulphur) should not exceed the value specified for the species concerned.

• Alloy steel – In addition to iron and carbon, it contains other components (2,5 – 5%) added to obtain the desired properties.

Steel used in construction is divided into classes and grades. The class of steel depends on its mechanical properties (tensile strength, yield strength). The class of steel is indicated by the letter A and the Roman numeral. Steel is produced in classes: TO THE, A-l, A-ll, A-III, A-IIIN (the higher the number, the higher the strength of steel). Within each class there are species that determine technological properties, such as: Weldability, weldability, degree of sedation (deoxidation process, thanks to which no reactions with the release of gases take place during solidification of steel and the steel has better quality).

Steel is subjected to various types of forming, as a result of which various products are obtained.

• Hot rolling – The process of crushing steel by pairs of rollers rotating in opposite directions. As a result of hot rolling,: Rods, Sections, Sheet, Pipes.

• Cold bending – It consists in the formation of flat sheets with a thickness 1,5-5 Mm. As a result of cold bending, thin-walled profiles of various shapes are obtained.

• Embossing – It consists in the plastic shaping of products by bending, Wrapping, Profiling, kneading As a result of pressing,: sheets of various shapes (Wavy, ribbed), Rivets, screws, Pins, Nuts.

• Cold or hot drawing – It consists in reducing the cross-section and lengthening the material. As a result of drawing, wires are obtained.

Steel products used in construction are sections, flat bars, Angles, I-beams and channel bars.

Reinforcement for concrete

■ Reinforcement cooperates with concrete to transfer internal forces occurring during the operation of the structure. Because concrete is a material with high compressive strength and low tensile strength, the main task of reinforcement is the transfer of tensile forces. Reinforcing steel is produced in the form of simple rebar, wire rod and wire.

Standard welded reinforcement meshes are also used for reinforcing concrete structures. They are made of smooth or cold profiled wire rods, crossing at an angle of 90°C and welded pointwise at the connection points Standard grids have dimensions 6 x 2.45 m.