Hot Rolled Vs Cold Rolled Sheet Metal

For example consumer electronics and telecom products metal furniture automobile industry etc.

Hot rolled vs cold rolled sheet metal.

During cold rolling the steel is annealed or exposed to heat and allowed to cool which improves ductility. Each type of steel has its advantages and disadvantages and costs for the two types of steel are also different. Hot rolling and cold rolling are two methods of shaping steel. Cold worked steels are typically harder and stronger than standard hot rolled steels.

Both hot rolled steel and cold rolled steel start out in essentially the same way and both can have the same grades and specifications. During the hot rolling process steel is heated to its melting point while being worked changing the composition of the steel to make it more malleable. The difference between hot rolled and cold rolled steel is this recrystallization point. Hot rolled steel sheets are used in fabrication work where aesthetics and quality are not very important.

Once hot rolled steel has cooled it is then re rolled at room temperature to achieve more exact dimensions and better surface qualities. Hot rolled steel is used in situations where precise shapes and tolerances are not required. Cold rolled steel is essentially hot rolled steel that has had further processing. Hot rolled products like hot rolled steel bars are used in the welding and construction trades to make railroad tracks and i beams for example.

This is why the tolerance for hot roll steel is looser than cold rolled steel. In comparison a cold rolled steel product with the same chemical composition has a yield strength of 365 mpa. Hot rolled steel also tends to be cheaper than cold rolled steel because of the reduced tolerances and slightly lower strength. Whereas cold rolled steel sheets are used for precision and quality fabrication work.

Cold rolling is done when the metal is able to form new grains as the old ones are deformed by rolling and bending the metal. The rolls induce plastic deformation. Thus the yield strength of cold rolled steel is higher than that of hot rolled steel. As an example a hot rolled steel product may have a yield strength of 235 mpa.

During this process the metal shrinks as it cools which can cause some slight warpage.