Steel comes in various grades, dimensions, shapes, finishes, textures and each with unique properties. The various types mean that steel can be widely used in infrastructure, appliances, vehicles, wind turbines, and many more applications. The basic difference between hot rolled steel and cold rolled steel is the way they are processed.
Processing Temperature: Hot rolled steel involves rolling steel above the recrystallization temperature. Because of shrinkage during cooling, the size and shape of the steel cannot be foreseen. In other words, they are manufactured within large tolerance values.
Cold rolled steel involves rolling of steel in reduced mills at below recrystallization temperature. This process occurs at room temperature. Hence steel shrinkage is low compared to the hot rolling process.
Manufacturing Cost: Hot rolled steel manufacturing cost is low compared to cold rolled steel.
Strength: Cold rolled steel produces higher strength compared to hot rolled steel. Therefore cold rolled steel is less likely to fail under pressure.
Sheet Quality and Finish: Cold rolled steel has a closed thickness profile, good smooth and shiny surface texture and flatness compared to Hot rolled steel which has grey, rough finish.
Application: Hot rolled steel sheets are used in construction work where beauty and standard are not very crucial. For example railway track, automotive frames, structural frames, low precision metal parts, etc.
Whereas cold rolled steel sheets are used for accuracy and quality manufacturing work .e.g. consumer electronics and telecom products, metal furniture, automobile industry, etc.
To sum up, hot rolled steel sheets are used to take impact load and for low-cost fabrication work. Whereas cold rolled steel sheets are used for very precise and quality work.