The type of sheet metal produced by cold rolling, that is, without heating the metal. As a blank, hot-rolled sheets are used. For this rental take the usual carbon steel, high carbon (Ст08пс, Ст08кп, Ст10кп, Ст10пс, Ст15пс, Ст15кп, Ст20пс, Ст20кп, Ст25, Ст30, Ст35, Ст40, Ст45) and low alloy, 20X, 40X, 09Г2С. Production of cold-rolled sheet is regulated by a number of GOST (which are described below), but in any case, the following parameters should be maintained:
- chemical composition of steel;
- geometrical dimensions - thickness, length, width, as well as their deviations from the nominal (in some cases, where the weight of the product plays a big role, this is important);
- edge type
The advantage of cold rolled sheet
Speaking about the benefits of this metal, it makes sense to compare cold-rolled sheet with hot-rolled sheet in order to have a clear idea of what the difference between them is.
Price of sheet cold-rolled metal
Hot-rolled sheet with the same geometric parameters is cheaper. This is explained by the fact that it is a billet for a cold-rolled sheet - it is first treated in a special solution to remove the dross, and then rolled to a cold one at the right size.
Strength characteristics
Cold-rolled sheets have higher strength characteristics due to the fact that in the production of cold-rolled steel sheet undergoes additional compression.
Geometry accuracy
Based on the opinion of experts who unequivocally state that the accuracy of the geometric parameters of a cold-rolled sheet is higher than that of a hot-rolled sheet.
Flatness
When cooled, the hot rolled sheet starts to warp from thermal stresses. With a cold rolled sheet, this does not happen. Therefore, its flatness is better.
Minimum thickness
A very important indicator for industries where weight plays a big role. Cold-rolled sheet can be made up to a thickness of 0.35 mm versus 0.4 mm for a hot-rolled sheet. In practice, hot-rolled sheets thinner than 1.8 mm are rarely used. It is too difficult to obtain a satisfactory flatness of the surface with smaller thicknesses. For the cold-rolled version, the practical field of application begins with 0.5 mm.
Corrosion resistance - in the hot-rolled version it is higher. But if we consider that sheets are rarely used without additional protection (at least with the help of painting), such an advantage can hardly be considered significant.
Types of cold rolled sheets
In addition to classification by steel grade, cold-rolled sheets can be divided according to signs showing its technical characteristics, such as accuracy, flatness and type of edge. And in terms of accuracy, GOST 19904-90 regulates the accuracy separately for three geometric dimensions:
By thickness
- normal;
- increased;
- high.
By lenght
- normal;
- elevated;
- high.
By width
- normal;
- increased;
- high (VS).
By flatness
- normal;
- improved;
- high;
- especially high (software).
By type of edge
- with edged;
- with unedged.
Cold rolled sheet applications
In the construction sector, such types of work as roofing, facing, the creation of fences and formwork can not do without the use of cold-rolled sheets. It should be said that due to a higher price than that of hot-rolled sheet, cold-rolled sheet in this area is used much less frequently. In the field of engineering from cold-rolled sheet create different types of stamped parts for the automotive industry, aircraft and shipbuilding. The electrical industry consumes these sheets, from which make various parts for electrical components. And still the cold-rolled sheet is a blank for creation of a professional flooring and other profiles.
