Finished products created by the cold rolled steel process include bars strips rods and sheets which are usually smaller than the same products available through hot rolled methods.
Cold rolled vs hot rolled sheet steel.
First hot rolled steel coil is manufactured and later it is run through a mill which forms the coil into the steel sheet pile sections.
The smaller products are also much more tolerant than the larger hot rolled versions.
Basic difference between hot rolled and cold rolled steel is the way they are processed.
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.
When the rolling is done above a certain temperature it prevents the steel from recrystallizing.
Once hot rolled steel has cooled it is then re rolled at room temperature to achieve more exact dimensions and better surface qualities.
The steel is processed further in cold reduction mills where the material is cooled at room temperature followed by annealing and or tempers rolling.
When to use hot rolled steel.
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.
Although this combines two processes the method as i will point out later has an advantage of economy and scheduling in the cold formed process.
During cold rolling the steel is annealed or exposed to heat and allowed to cool which improves ductility.
Hot rolling and cold rolling are two methods of shaping steel.
Hot rolled steel is rolled or shaped at a high temperature while cold rolled steel is rolled at room temperature.
In this article we will compare hot rolled vs cold rolled steel sheets.
Hot rolled steel has rounded edges a rough surface texture and no grease on its finish.
Cold rolled has sharper corners and more precise dimensions than hot rolled.
Cold rolled has a smooth and shiny finish while hot rolled has a grey and scaly finish.
Whereas cold rolled steel is processed in cold reduction mills followed by annealing and tempering.
This process is called hot rolling.
Hot rolled steel involves rolling the steel above re crystallization temperatures.
Rolling performed below a specific temperature will allow for recrystallizing and is called cold rolling.
Alternatively cold rolled steel has sharp edges a very smooth surface texture and an oily or greasy feel to it.
Cold worked steels are typically harder and stronger than standard hot rolled steels.