Identification & Benefits of hot rolled steel

by Anirudh Kumar professional WRITTER

Steel is available in many shapes, finishes, specifications and grades; infact, according to the World Steel Association there are more than 3,500 various grades of steel and each has its unique properties. Thesedifferent types of steel have a diverse usage acrosssectors in the automobile industry, construction industry, for utensils, wind-turbines, infrastructure, appliances, vehiclesamongst many other industries.

What is hot rolled steel?

Steel which is roll-pressed at extremely high temperature around 1,700˚F and more is known as hot rolled steel. The reason this temperature is chosen is because it is higher than the re-crystallization temperature for most steels. This makes the steel malleable and results in products which are easy to work with.

The process of hot rolling steel involves heating a billet and passing it through a series of rollers to achieve the finished dimensions. It is then left to cool and as a result it shrinks. Since it is processed before cooling the final shape and size gets slightly altered making it unsuitable for applications where precision is important.

Identification of hot-rolled steel

The following characteristicscan help one identify hot rolled steel:

· The surface will be slightly scalyas a result of cooling down from extreme temperatures

· The edges and corners are slightly rounded due to lack of precision and shrinkage

· The final shape is slightly distorted as a result of which the result may take slightly trapezoidal forms instead of perfect squares

Hot rolled steel comes with the following benefits

As compared to cold rolled steel, hot rolled steel typically requires lesser processing making it a cheaper option. An HR coil price will be significantly lower than a CR coil, or an HR sheet will be more affordable than a CR sheet. As hot rolled steel cools at room temperature, it’sbasicallynormalised which means that it is devoid of any internal stresses that arise due to quenching or work-hardening procedures.

For some applications, overall material strength is given more importance over dimensional tolerances and surface finish; for such scenarios hot rolled steel is ideal. Also, the scaling can be removed and other finishes such as brush or mirror finishes can be applied, making hot rolled steel a better option for painting and coating.

Hot rolling is a monetarily more attractive option for many metalworking companies due the low cost of production. It is very malleable and can be easily deformed and manipulated in order to get desired shapes as it is heated above the crystallization temperature.