Hot Vs Cold Rolled Sheet Metal

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.

Hot vs cold rolled sheet metal. Hot rolling and cold rolling are two methods of shaping steel. Cold rolled steel is essentially hot rolled steel that has been through further processing. Cold rolled steel cold rolled steel is essentially hot rolled steel that has gone through more processing. Both hot rolled steel and cold rolled steel start out in essentially the same way and both can have the same grades and specifications.

From the point of view of metal the boundary between cold rolling and hot rolling should be distinguished by recrystallization temperature. During cold rolling the steel is annealed or exposed to heat and allowed to cool which improves ductility. This is important because cold rolled steel is going to be strongest when it s laid with the grain and is significantly weaker against the grain. Note that cold rolled steel has grains while hot rolled steel does not.

Cold rolled steel is essentially hot rolled steel that has had further processing. Thus the yield strength of cold rolled steel is higher than that of hot rolled steel. For example railway track automotive frames structural frames low accuracy sheet metal parts etc. 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 main advantages of cold working are. Compared to hot rolled steel cold rolled steel has a nearly 20 increase in strength through the use of strain hardening. Cold worked steels are typically harder and stronger than standard hot rolled steels. But cold rolled steel undergoes additional processing steps resulting in improved properties that can be exploited for different applications.

Cold rolling steel allows for the creation of very precise shapes. Cold rolled is a normal temperature hot rolled is a high temperature. Whereas cold rolled steel sheets are used for precision and quality fabrication work. Hot rolled steel sheets are used in fabrication work where aesthetics and quality are not very important.

Hot rolled steel is used in situations where precise shapes and tolerances are not required. As an example a hot rolled steel product may have a yield strength of 235 mpa. Cold rolled steel is going to be stronger overall than hot rolled steel. Once hot rolled steel has cooled it is then re rolled at room temperature to achieve more exact dimensions and better surface qualities.

Each type of steel has its advantages and disadvantages and costs for the two types of steel are also different. It s through a series of breakdown semi finishing sizing semi roughing roughing and finishing that cold rolled steel shapes can be created.