Engineers working with sheet metal, often come up with this question. What is the differences between hot rolled steel and cold rolled steel ?
Basic difference between hot rolled and cold rolled steel is the way these metals are processed. Hot rolled steel involves rolling the steel at high temperatures, where cold rolled steel is processed in cold reduction mills where the material is cooled followed by annealing and/or tempers rolling.
In this article we will discuss difference between these two materials based on manufacturing process, cost, properties and applications.
Process of hot rolling involves rolling steel at a temp above recrystallization temperature. Size and shape of the steel will be less predictable because during cooling process steel will shrink.
Whereas the process of cold rolling involves rolling of steel in reduced mills at below recrystallization temperature. Cold rolling process is done at room temperature. As a result there is low chances of steel shrinkage
Hot rolled steel is cheaper to manufacture as compared with cold rolled steel.
Yield and tensile strength of Cold rolled steel will be higher than hot rolled steel sheets. which makes cold rolled less likely to fracture under pressure.
Sheet Quality & Finish
Cold Rolled steel will have closed thickness profile and good surface texture & flatness compared with Hot Rolled Steel.
Cold rolled has a smooth and shiny finish while hot rolled has a grey and scaly finish.
Hot Rolled steel sheets are available in range of 1.60 mm to 10.00 mm thickness. Whereas Cold rolled steel sheets are available from 0.10 mm to 4.00 mm thickness.
Hot rolled steel is used in fabrication work where aesthetics are not important. Whereas cold rolled steel is used where precision work and quality of steel is important factor in final product.