Metal Rolling Machine

Rolling is term simplifies as  sheet of metal  pressed by  two, three or more roll. A plate rolling machine is a machine that will roll different types of metal sheets into round or conical shapes. It can also be called "roll bending machine", "plate bending machine" or "rolling machine".

And in other term Roll forming is a continuous metal forming process involving taking a sheet, strip, or coil stock and bending or forming it into a continuous cross section. The process is performed between successive pairs of rolls that resize until the desired section is completed.

The roll forming process can be used to create different types of cross-section profiles. An open profile is the most common, but a closed tube-like shape can also be formed. Because the final form is obtained through a series of bends, the part does not require a symmetric cross-section.
In metals, rolling is a metal forming process in which the metal stock is passed through one or more pairs of rolls to reduce the thickness and make the thickness uniform. The concept is similar to the rolling of dough. Rolling is classified according to the temperature of the metal being rolled. If the temperature of the metal is above its recycling temperature, the process is known as hot rolling. If the metal temperature is lower than its recycling temperature, the process is known as cold rolling. In terms of use, the hot rolling process carries a higher tonnage than any other manufacturing process, and cold rolling processes the highest tonnage outside of all processes. All roll holding pairs are grouped together into rolling mills that can process metals, usually steel. , In products such as structural steel (I-beam, angle stock, channel stock), bar stock, and rail. Most steel mills have rolling mill divisions that convert semi-finished casting products into finished products.

Type of Rolling 

  1.  Hot Metal Rolling Machine

  2.  Cold Metal Rolling Machine

Hot Metal Rolling Machine

 Hot rolling is a metallic process that occurs above the material's recycling temperature. After the grains deteriorate during processing, they are recycled, which maintains a homogenous microstructure and prevents the metal from working. The starting materials are usually large pieces of metal, such as semi-finished casting products, such as slabs, blooms, and billets. If these products came from a continuous casting operation, the products are usually fed directly to rolling mills at the appropriate temperature. In small operations, the material starts at room temperature and must be heated. This is done in a gas- or oil-soaked pit for large workpieces; For smaller workpieces, induction heating is used. As the material is worked on, the temperature must be monitored to ensure that it remains above the recycling temperature. A refining temperature is defined above the re-crystallization temperature to maintain a safety factor; It usually occurs above temperatures of 50 to 100 ° C (90 to 180 ° F). If the temperature drops below this temperature, the material must be reheated before rolling more hot

Cold Metal Rolling Machine

Cold rolling occurs with the metal below its recycling temperature (usually at room temperature), which increases strength through strain hardening by up to 20%. It also improves surface finish and has a tight tolerance. Typically cold rolled products include sheets, strips, bars, and rods; These products are usually smaller than those products that are hot rolled. Due to the small size of the workpiece and their greater strength, four-high or cluster mills are used when compared to hot rolled stocks. Cold rolling cannot reduce the thickness of a workpiece because hot rolling in a single pass.

Cold rolled sheets and strips come in various conditions: full-hard, half-hard, quarter-hard, and skin-rolled. Thickness is reduced by up to 50% in full-rigid rolling, while in others the reduction is small. Cold rolled steel is then induced to ductility into cold rolled steel, known simply as a cold rolled and closed annealed. Skin-rolling, also known as skin-pass, contains the least amount: 0.5–1%. It is used to have a smooth surface, uniform thickness, and to reduce the yield point incidence (by preventing the ludes band from forming in subsequent processing). This closes the clutter at the surface and reduces the possibility of formation of ludder bands. To avoid the formation of the Lüders band it is necessary to create a sufficient density of unpinned clasts in the ferrite matrix. It is also used to break spangles in galvanized steel. Skin-rolled stock is commonly used in subsequent cold working procedures where good flexibility is required.

 Type of Rolling Machine On The Basis of No of Roll

 

A. Two Roll Rolling Machine

B. Three Roll Rolling Machine

C. Four Roll Rolling Machine

D. Six Roll Rolling Machine

E. 12 Cluster Rolling Machine

F 20  Cluster Rolling Machine



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