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Hot and Cold Rolling
Hot and Cold Rolling
January 11, 2017

A roll forming machine is usually separated into different cages; roughing, intermediate, and finishing. The roll forming machine can use different sequences to produce a finished product starting from a slab or billet. Items such as I-beams, railings, tracks, hinges, and tubing are results of a roll forming machine. Roll forming machines are an efficient and effective method of mass producing quality items. Depending on the type of product and the type of metal, one of two types of rolling were used to manufacture it.

Roll Forming Machines: Hot and Cold Rolling Explained

Hot Rolling

The roll forming machine heats slabs or billets above the recrystallization temperature, then deformed between rollers. The rolling process measures at temperatures over 1000 degrees Fahrenheit. Because of the intense heat, some metals will discolor during the process. For example, steel will give blue-gray finish and acquire a rough surface.

Hot rolled metal would also slightly change its shape and size when cooling. For example, hot rolled steel reconfigures itself during cooling processes, giving looser tolerances and is more malleable. The hot rolling process is useful for manufacturing structural components like I-beams, cross sections, and sheet metal.

Cold Rolling

The roll forming machine passes the metal slab or billet through rollers below recrystallization temperatures, at approximately room temperature. This method increases the strength of finished products because the strain hardens the metal up to 20 percent. This does not discolor metal. For example, steel products retain a gray finish.

Finished products are more precise through the cold rolling process because there is no size change when cooling. However, cold rolled products are limited to variations of round, square, and flat shapes. The shaping operations include sizing, breakdown, semi-roughing, semi-finishing, roughing, and finishing. The cold rolling process is useful for products like bars, strips, rods, and sheet metal. Cold rolled steel sheets can come as full hard, half hard, quarter hard, and skin rolled.

I agree Isaac.
Posted by: Jenn | March 23, 2017, 9:28 pm
great article, thanks!
Posted by: isaac | January 11, 2017, 10:13 pm
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