Iron is a material that has been used in many ways since the earliest ages of humanity. Because of its resistant and long lasting structure, iron has been used for tool making in the past. Such that, there is even a period in human history called the “iron age”. The use of iron has diversified over time and become a major material in all areas for daily life. With the growing population, construction of apartments and high buildings increased because of the need for housing. Steel is a material obtained as a mixture of iron and carbon. Because it’s durable, steel is mostly used in construction and various industrial sectors.
Hot rolled coils are preferably used in areas that do not require much shape change and force. This material is not just used in constructions; hot rolled coils are often preferable for pipes, vehicles, railways, ship building etc. While making hot rolled coils; firstly steel is milled at high temperature. Then melted steel casted into the steel slab which is afterwards rolled into the coil.
To process hot rolled steel, manufacturers first start with a large, rectangular length of metal, called a billet. The billet is heated and then sent for pre-processing, where it is flattened into a large roll. From there, it is kept at a high temperature and run through a series of rollers to achieve its finished dimensions.
Hot rolled steel typically requires much less processing than cold rolled steel, which makes it a lot cheaper. Because hot rolled steel is allowed to cool at room temperature, it’s essentially normalized—meaning it’s free from internal stresses that can arise from quenching or work-hardening processes.
It’s important to note that the main difference between hot rolled and cold rolled steel is one of process. “Hot rolling” refers to processing done with heat. “Cold rolling” refers to processes done at or near room temperature. Although these techniques affect overall performance and application, they should not be confused with formal specifications and grades of steel, which relate to metallurgical composition and performance ratings.
In terms of physical characteristics, cold rolled steels are typically harder and stronger than standard hot rolled steels. As the metal is shaped at the lower temperatures, the steel’s hardness, resistance against tension breaking, and resistance against deformation are all increased due to work hardening.
