Steel Allied Products » Steel Sheets » Cold Rolled Steel Sheet

Cold rolled sheet is commonly known as 'white steel'. This variety of sheet is produced by the cold rolling process. The cold rolled sheet has specific characteristics that are different from the hot rolled steel sheet variety. This sheet has good formability and mechanical properties. Cold rolled steel sheet serve as a major input in a wide range of industries. Cold rolled steel sheets are supposed to have good surface finish, high standards of heat treatment and has thinner and better gauges. Cold rolled steel sheets are available since many years and have been used in many applications. The cold rolled sheets have been improvised over the years. The improvisation has been in terms of:

• Shape
• Width
• Thickness
• Surface finish

This variety of steel is ideally used for coating purposes for other different usages. The different industries wherein cold rolled steel sheet is used are:

• Enamelware (porcelain-coating)
• Galvanizing (zinc-coating) industries
• Tin-coated food can (tin mill-black plate) industries

Specific features of Cold Rolled Sheets:
The cold rolled sheets are so designed that they have specific attributes like :

• Deep drawability
• High strength
• Good magnetic properties
• High dent resistance
• Paintability
• Enamelability
• Formability

Manufacturing Process:
The cold rolled steel sheets are produced keeping in mind the end usage. There are various factors that need to be kept in mind while manufacturing the cold rolled steel sheet. The first step is the cold reduction operation. This procedure not only makes the steel sheet thinner but makes it harder, less ductile and very difficult to form. After this the product is annealed, i.e., heated to high temperatures hence making it very soft and formable. This unique combination of cold reduction and annealing makes the steel refined which enables the customer to get the desirable and unique forming properties. The main feature of the cold reduction is to reduce the thickness of the hot rolled coils which is not possible in the hot rolled state. It is actually very important to maintain the uniformity in the sheet thicknesses so that the sheet performs consistently when used by the end user. There are other factors which needs to be taken care of in the cold rolling process like, flatness-meaning deviation from a flat plane. The flatness is maintained by the usage of very sophisticated strip shape controlling technology. Surface finish is another attribute that is taken care of during the cold reduction process.

The following are the different processes that are helpful in producing high quality cold rolled sheet products, like-

• Hot strip mill processing variables
• Pickling practices
• Annealing practices
• Temper rolling practices
• Steel chemistry
• Cold-rolling mill practices

Application

• Oil barrels & containers
• Bicycles
• Refrigerators
• Automobiles
• Domestic Appliances
• Electronics & Electrical components
• Washing Machines & geyser

Types of Cold Rolled Steel Sheets:
The cold rolled steel sheets products are produced keeping in mind the end usage of the product. Thus there are variants of cold rolled steel sheets that are available. They are mentioned below:

• Cold Rolled Full Hard Sheet Steel
• Vitreous Enamel Sheet (Vitrenamel)
• Cold Rolled Motor Lamination Sheet

Cold Rolled Full Hard Sheet Steel:
These product mainly used in further application such as continuous galvanizing. The following specifications should be mentioned while placing an order:

• Dimensional tolerances
• The steel chemistry
• Sheet dimensions
• The metallurgical designation, i.e., Commercial Steel, Drawing Steel, etc.

Vitreous Enamel Sheet (Vitrenamel):
This is a cold rolled steel sheet product processed with enhanced qualities for porcelain enameling. Similar to the cold rolled steel sheet, Vitrenamel Sheet can be ordered according to the specific needs. Such enameled sheets are extensively used in door and cabinet laminates.

Cold Rolled Motor Lamination Sheet :
This specific kind of cold rolled steel sheet is made to be used for electromagnetic core material for electrical equipment components. Such sheets are generally used in generators, transformers, motors. The main factor kept in mind while manufacturing this sheet is the core loss. Core loss means the electrical loss in electrical equipment due to heat generation by alternately magnetizing and demagnetizing the components. The degree of the core loss is decided by the chemical composition of the steel and the core material processing. Another factor is the permeability, meaning the ease of magnetization.