Suspension Type Roughing Mill Roll Characteristics
Roughing mill rolls are used for hot rolling of steel billets and slabs. The purpose of roughing is to reduce the cross section of the workpiece and to eliminate any surface defects. This process is also used to shape the final product, such as steel sheets or plates. The main type of roughing mill is the suspension type, which uses an elastic support structure to allow the rollers to make continuous contact with the workpiece. The suspension type has several advantages over other types of roughing mills, such as the ability to roll thinner sheets and higher speeds.
The characteristic of a suspension type roughing mill roll is determined by its internal structure. The inner core of a roll is generally made of hard cast iron or steel and is called a backer. The outer layer of the roll is composed of chrome-moly or other wear resistant steel. The role of the backer is to provide support, stability, and even pressure distribution to the outer layer of the roll. This allows for a more consistent and uniform rolling process.
The surface texture of a suspension type roughing mill roll is important for several reasons. The texture of the outer covering affects the friction between the workpiece and the roll, which influences the quality of the product. In addition, a rougher texture can help to evenly distribute an applied load. Additionally, the surface texture of the roll can also affect the speed at which it is operated.
Generally, the surface textures for roughing mill rolls are classified into three basic types: coarse, intermediate and fine. The coarse surface is characterized by large and irregularly arranged grains. The intermediate surface has small, regular grains that are flattened. Finally, the fine surface has a very smooth finish with very small grains. The surface finish of a suspension type roughing mill roll is often determined by the specific application and the equipment used to roll the workpiece.
The lifespan of a suspension type roughing mill roll is usually determined by its performance. In general, a good quality roll should last for approximately 10–20 rolls per tonne of production. The total number of rolls for a single job will depend on the particular application and the required finish. The wear resistant properties of suspension type roughing mill rollers also play an important role in ensuring their longevity. Generally, the higher the wear resistance of a roll, the longer it will last.
In conclusion, suspension type roughing mill rolls provide several advantages and are widely used in the hot rolling of steel products. They are characterized by the inner core of hard cast iron or steel, the outer layer of chrome-moly or other wear resistant steel, and by their surface finish, which can range from coarse to fine. The wear resistant properties of these rollers play an important role in ensuring their longevity, which is generally determined by their performance.
