TECHNICAL FIELD

The invention relates to the metal sheet material needed in various industrial fields such as building equipment, machine production, prefabricated buildings, ship industry, motorways, construction, pipes, profiles and accessories.

In particular, the invention relates to the cold rolled hot steel roll (CHRC) which is needed in various industrial fields such as building equipment, machine production, prefabricated buildings, ship industry, motorways, construction, pipes, profiles and accessories;

- obtained with a matt surface without applying expensive and environmentally harmful procedures such as sand blasting and picking in consequence of bringing back to its old form by recrystallizing after rolling of the hot rolled flat steels with a width of 30 - 1250 mm and a thickness of 1 .30 - 4.00 mm to the thickness of 0.50 1 .60 mm by applying the cold rolling technique and offered to the customers in various forms such as rolls, packages and bands; in compliance with the EN standards of DD1 1 , S235JR, S275JR.

BACKGROUND OF THE INVENTION

Metal sheet material is needed in various industrial fields such as building equipment, machine production, prefabricated buildings, ship industry, motorways, construction, pipes, profiles and accessories. There are three types of rolled steel rolls in the current standards. The first one is the product called hot steel roll (HR) and produced as a result of rolling the raw material (Slab, Billet, Bloom etc.) by annealing at the recrystallization temperature (between 50% - 75% of the melting temperature) of 1000 on average.

The second and third rolled products are cold rolled and they are called CR and DKP. In both of the production processes, prior to rolling, the hot sheet metal is prepared for rolling by removing more than 90% or even all of the scale layer which has connected with the surface of the stable (powder-scale) and stable material on the surface of the material by means of sand blasting and picking processes (HRP) and it is produced full-hard by cold rolling to 90% (CRF). In the state of the art, there are a number of problems in the production, storage and usage of the steel rolls obtained through the above-mentioned process. These problems are;

- A scale layer is formed on the surface of the hot steel roll in the production stage.

Complete removal of the scale later comprises chemicals that are both expensive and environmentally harmful and elimination of the said chemicals brings about another cost.

- As a result of the complete removal of the scale layer which has formed a stable connection with the material, raw steel becomes less resistant against corrosion. As a consequence, the formation of corrosion is tried to be prevented by coating with many chemicals (protective oil, corrosion inhibitor) when the material is at the production stage. This then creates operation redundancy, work force, time and associated cost increases.

- A significant part of the businesses that are end-product manufacturers have to clean the chemicals used in order to prevent corrosion of cold rolled sheet metal before the production or during the production or after the production. Otherwise coating of dye cannot establish a connection with the material.

- It makes it necessary to use expensive dyeing techniques even in simple manufactures as the sheet metal surface is extremely clean and smooth.

- As a result of the researches, studies and trials we carried out, we observed that cost advantage of more than 50% is provided with the cold rolled hot steel roll (CHRC), compared to the cold rolled CR and DKP products.

Consequently, it becomes evident that there must be improvements in the art due to the above-mentioned problems faced in the state of the art.

OBJECT OF THE INVENTION

The invention, as a result of the problems present in the prior art, aims to solve all of these problems. The object of the invention is to provide production of the cold rolled hot steel roll (CHRC) which is needed in various industrial fields such as building equipment, machine production, prefabricated buildings, ship industry, motorways, construction, pipes, profiles and accessories;

- obtained with a matt surface without applying expensive and environmentally harmful procedures such as sand blasting and picking in consequence of bringing back to its old form by recrystallizing after rolling of the hot rolled flat steels with a width of 30 - 1250 mm and a thickness of 1 .30 - 4.00 mm to the thickness of 0.50 1 .60 mm by applying the cold rolling technique and offered to the customers in various forms such as rolls, packages and bands; in compliance with the EN standards of DD1 1 , S235JR, S275JR.

Thanks to the cold rolled hot steel roll of the invention;

- there are no additional anti-rust/corrosion substances on the sheet metal,

- the manufacturers can use the cold rolled hot steel roll they have supplied directly in production,

- the need for applying expensive dyes on the sheet metal and production costs are reduced for the manufacturers.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to the cold rolled hot steel roll (CHRC) needed in various industrial fields such as building equipment, machine production, prefabricated buildings, ship industry, motorways, construction, pipes, profiles and accessories.

The production procedure of the cold rolled hot steel roll (CHRC) of the invention, hot rolled flat steel with a width of 1250 mm and a thickness of 1 .30 - 4.00 mm is rolled to the thickness of 0.50 - 1 .60 mm by using the cold rolling technique. The metal sheet rolled to the thickness of 0.50 - 1 .60 with the cold rolling technique is brought back to its old form by recrystallizing. The surface of the cold rolled hot steel roll (CHRC) which is produced in the above-described manner is matt and no expensive and environmentally harmful procedure such as sand blasting and picking is used during production.

The cold rolled hot steel roll (CHRC) of the invention complies with the standards DD1 1 , S235JR, S275JR in EN standards. If the cold rolled hot steel roll (CHRC) of the invention is desired as a metal sheet rather than a roll, cold rolled hot sheet metal (CHR) is obtained and offered to the users by cutting in particular dimensions. As mentioned above, cold rolled hot steel roll (CHRC) is offered to the user in various forms such as rolls, packages and bands. Users/manufacturers can enter the cold rolled hot steel roll (CHRC) they supplied directly to the production without additional procedures such as surface cleaning and sand blasting, and there is no need for applying expensive dyes to the surface.