Steel is an important commodity for manufacturing, engineering and construction industry. Steel became popular due to its high tensile strength, flexibility, and low cost. Steel is most widely used in the form of steel coil made from steel slabs. There are various grades or classifications of steel coils and used across industries for a myriad of functions. Steel coils are made by hot rolling, cold rolling, or by using the Electrolytic Tinplate (ETP) method.
The quality of steel coils depends on the grade of steel you choose. Depending on the grades of steel, coiled steel will have different mechanical properties and specific chemistry. There are about 3500 steel grades with various physical, chemical and mechanical features that have been developed around the world. Steel coils are therefore chosen based on the specific uses of a company.
For example, a car manufacturer uses Advanced High-strength Steels (AHSS) while the construction industry usually utilise Fe 415 and Fe 500 grades of steel.
Let us take a closer look at the meaning of steel coils and their classifications, and the use of steel coils in industries.
Steel coil definition and benefits
To answer the question of ‘what is steel coil?’, steel coil is defined as sheet or strip of steel that is wound or coiled after rolling. It is manufactured by placing a slab into a continuous rolling machine to reduce its thickness until it forms a sheet. This sheet is then wound into coils.
• Excellent heat resistance
• Low maintenance
• Safe to use
Steel coils can be formed into any shape and are often used along with other materials to create specific shapes. Coiled steel is used for a variety of applications including building components, machinery and electrical equipment, kitchen appliances, etc.
Some of the widely known steel coil uses include:
Manufacture of automotive parts
Automotive parts including the shell of the vehicle, chassis, suspension, rims, exhaust system, etc., are made of steel. Durability, heat resistance, high strength-to-weight ratio and non-combustibility of steel coils make them the ideal choice for an automobile engine.
Computers, smartphones, circuit boards, etc., are made of steel coils. Since steel has a high melting point it is apt for use in making electronic goods. Steel also contributes to electrical devices being cost effective.
Steel rolling machines have allowed pipes to be continuously rolled into long pipelines without the need of welding pipes together to form a long pipeline. These are used as gas pipelines and in the construction of houses for heating, plumbing, etc.
Railroads use carbon steel coils due to their high flexibility. It has the ability to expand without changing shape, making it suitable for train wheels running on railway tracks.
Considering the wide range of steel coil use, procurement of steel as a raw material has always been vital for businesses. Today, steel coils can be purchased online that gives businesses the option to compare prices, delivery timelines, quality, and other details before purchase. Tata nexarc’s Procurement is one such place where you can buy steel online at competitive prices hassle-free.
Also Know: Latest Steel price in India Today
Steel coil classification
Steel coils are classified into two main categories according to the steel coil processing method used:
Hot rolled coils are manufactured in hot-rolling mills. Hot-rolling is the metal-treatment process that takes place at high temperatures approximately more than 2000 degrees Fahrenheit above the recrystallisation temperature of most steel types. Hot rolling begins when a large, long steel called billet is heated and sent to a large roll to be flattened into sheets. It is then passed through a series of rolls maintaining its high temperature until they reach the desired dimensions. These steel sheets are then spun and left to cool.
Since hot rolled steel is cooled after processing, it shrinks leading to less control over its final shape. This makes it less suitable for precision applications. Railway tracks and construction projects often use hot rolled steel.
Hot rolled steel is usually identified using the following characteristics:
- A scaled surface which is an after-effect of cooling from extreme temperatures.
- Slightly rounded edges and corners for bar and plate products due to shrinkage and lack of precision finishing.
Cold rolled steel coils
Cold rolled steel coil is an output of hot rolled steel. Hot rolled steel that is cooled completely is re-rolled at room temperature to produce cold rolled steel coil. This steel coil processing method helps achieve exact dimensions and better surface qualities.
Cold rolled steel coils undergo the rolling process which are metal sheets put between two rollers. There are other cold finishing processes including turning, grinding, and polishing. These processes are used to modify the hot rolled steel into more refined products.
Cold rolled steel is usually identified using the following characteristics:
- Smooth finished surfaces
- Well-defined edges and corners
- Better uniformity
There are also other kinds of steel coils including galvanised steel coil, carbon steel coil and stainless-steel coil. All these types of coils have varying mechanical and physical properties.
Steel coil specifications depend on the type of steel coil in question. For example, while the thickness range of commercial quality galvanised steel coil is 0.14-0.80 mm the thickness range of carbon coil steel is from 0.0508 – 0.889 mm. Steel coil sizes also vary according to the supplier.
Before choosing the steel coils for your business, learning how steel coils are categorised and the applications of different steel coils can help you pick the perfect steel coil product for your manufacturing processes.
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