Rolling
Rolling is a metal forming process which is used to transform metal into different shapes, sizes and forms. It is also called deformation rolling as this process involves deforming the metal under force by passing it between rolls. Rolling is especially important in today’s production process as it allows us to increase uniformity and strength of metals while at the same time reducing costs that are associated with time and wastage.
Rolling can be classified into three main types, namely longitudinal, transverse and diagonal rolling.
Longitudinal Rolling
Longitudinal rolling is a traditional way of forming metal. It involves the application of compressive forces by passing the metal between two rollers. The rollers, called roll stands, are usually arranged either parallel or in a V-shaped arrangement. In this process, the metal is fed, or passed through the two rollers. The arrangement of the rollers should be such that, the metal passes through them in one direction as it comes out on the other side in its original shape.
Advantages
Longitudinal rolling can be used for a wide range of metal sizes and shapes. It is ideal for round and square materials, when the rollers are arranged in the same direction, giving a uniform product. It is ideal for large scale production as it has a lower cost and requires minimal tooling.
Disadvantages
This type of rolling is difficult to control as the metal is compressed by large forces which cannot be accurately controlled. The metal may also suffer greater work-hardening and substantial deformation.
Transverse Rolling
Transverse rolling, sometimes called Edge Rolling is considered a modern method for forming and shaping metals. It involves the application of shear forces between specially designed rollers. These rollers are usually arranged in a V-shape as the shape of the rollers is designed to bring the shear forces to cut or form the metal.
Advantages
Transverse rolling is preferred to longitudinal rolling due to the great flexibility it offers. It requires minimal tooling, and less cost. It also ensures that more uniformity and precision of the product is achieved. It is preferrable to use this process when forming large pieces of the metal.
Disadvantages
This process requires specially designed rollers and hence, can be quite expensive to operate. Additionally, it is not suitable for large scale production and is also more time consuming.
Diagonal Rolling
Diagonal Rolling, sometimes known as torsion rolling is a combination of longitudinal and transverse rolling. It is basically the process of rolling a strip of material at an angle to the strip length. This is achieved by using two pairs of rolls, one in each the longitudinal and transverse directions, and then, simultaneously rolling the strip by shear forces between the two pairs of rolls.
Advantages
Similar to Transverse Rolling, Diagonal Rolling is associated with great flexibility as it can be used to form complex shapes. It ensures uniformity and precision in the products.
Disadvantages
This process can be quite tricky to master as a high level of expertise and experience is needed to set-up the rolls and apply the right shear forces in order to get the desired shape. Additionally, it is costlier due to the custom made rolls that are necessary to make it work.
In conclusion, rolling is a very versatile and important manufacturing process used in many industries today. There are three types of rolling, namely longitudinal, transverse and diagonal rolling. Each of these types has its own advantages and disadvantages. Longitudinal rolling is the most traditional and cost-effective process and is suitable for large scale production. Transverse rolling is preferred for its great flexibility, while Diagonal rolling is preferred for forming complex shapes. Whichever type of rolling process is employed for the job, care should be taken to ensure that the rolled product meets the necessary specifications.
