Definition - What does Flat-Rolled Steel mean?
Flat-rolled steel is produced through melting and rolling. It is produced in sheet, strip and tin plate formats. It is commonly used in automotive, heavy machinery, pipes and tubes, construction, packaging and appliances.
Flat-rolled steel products include slabs, hot-rolled coils, cold-rolled coils, coated steel products and heavy plates.
These types of steel have flat faces rather than grooved or cut faces. They are coated with zinc to help prevent corrosion of the steel substrate.
Corrosionpedia explains Flat-Rolled Steel
Flat-rolled steel is a type of steel sheet that is manufactured by rolling. Flat rolling is the most basic form of rolling, with the starting and ending material having a rectangular cross-section. The material is fed between two rollers, called working rolls, which rotate in opposite directions. The final product is either a sheet or plate, with the former being less than 6 mm (0.24 in) thick and the latter being greater than that. However, heavy plates tend to be formed using a press, which is known as forming, rather than rolling.
The rolls are often heated to assist in the workability of the metal. Lubrication is often used to keep the workpiece from sticking to the rolls. To fine tune the process, the speed of the rolls and the temperature of the rollers are adjusted.
In order to produce flat material, the material must be reduced by the same percentage across the width. This is important because mass flow of the material must be preserved, and the more a material is reduced, the more it is elongated. If a material is elongated in the same manner across the width, then the flatness going into the mill is preserved at the exit of the mill.
The corrosion of a cold-rolled steel sheet surface requires that an aqueous electrolyte be in contact with that surface. No corrosion occurs, even at relative humidity approaching 100 percent, if the steel surface is free of contaminants, if the surrounding atmosphere is uncontaminated, and if condensation is avoided by keeping the temperature constant.