What is a roll?
The roll is an important part of the rolling mill, which uses the pressure generated by a pair or group of rolls to roll the steel. It is mainly affected by dynamic and static load, wear and temperature change during rolling. As the most important consumption part of the rolling mill, the production process of the roll is complicated.
The role of the roll is to change the shape and size of the metal material through rolling, and also to improve the strength and hardness of the metal material. In addition to the role in the processing of steel, aluminum and other metal materials, rolls are also widely used in metal processing, shipbuilding, aerospace, automobile manufacturing, electric power equipment and other fields.
What is the material of the roll?
In general, the materials used to manufacture rolls need to have high strength, high wear resistance, good corrosion resistance and fatigue resistance. Commonly used roll materials include forged steel, cast steel, cast iron, non-ferrous metals and synthetic materials. Which material to choose depends on the requirements and working environment. For example, forged steel is a commonly used roll material with high strength and good wear resistance; Cast steel has better toughness and fatigue resistance; Cast iron has the advantages of high wear resistance and low price. High speed steel, alloy steel, carbide and other commonly used roller materials. High speed steel rolls are widely used in the production and processing of cold rolled sheet, cold rolled strip, gear, screws and other products. Alloy steel rolls are suitable for high-speed wire rolling, bar rolling, strip rolling and other fields. Carbide roll is suitable for rolling, processing and cutting of workpiece surface and inner wall. It is also widely used in drum machine, road roller, cement pipe machine, excavator and other equipment.
In addition to the common metal rolls, there are non-metallic rolls such as ceramic rolls, rubber rolls and so on.
Ceramic roll application:
Steel industry: Ceramic rolls are used in both hot and cold rolling production lines in the steel industry. Due to its high temperature wear resistance and chemical stability, ceramic rollers can withstand high temperatures and pressures, maintain a long service life, and do not pollute the hot rolled steel plate.
Automotive industry: Ceramic welding rollers can be applied to the automotive industry, mainly for the welding of automotive internal exhaust pipes and oil pipes. The welding tool made of ceramic can achieve high-speed and continuous welding, ensuring that the welded product has high stability, consistency, and no magnetic, insulation, high temperature resistance.
Application of rubber roll:
Rubber roll has a wide range of applications, mainly used in various conveyors, elevators, belt conveyors, mixers and other machinery supporting use. For example, in the roller of the belt conveyor, the rubber roller can support the conveyor belt and maintain the stability of the operation; In the reversing drum of the scraper conveyor, the rubber roller can play a role in changing the direction of transmission. In addition, the rubber roller can also be used in the feeding funnel of the ball mill and the cone roller in the inclined feeder for mineral processing.
The application advantages of rubber rollers mainly lie in their good sealing and wear resistance. It can adapt to most processing conditions, so it plays an irreplaceable role in industrial production.
The roll manufacturing process consists of the following steps:
Raw material preparation: The raw materials of the roll mainly include cast iron, steel, alloy, etc. Select the appropriate raw materials according to the roll specifications and performance requirements, and check the raw materials to ensure that their quality meets the requirements.
Casting: The mold is made according to the size and shape of the roll, and then the melted raw material is poured into the mold, waiting for it to solidify. In this process, parameters such as pouring temperature, pouring speed and cooling speed need to be controlled to ensure the finish of the roll surface and the density of the internal structure.
Heat treatment: In order to improve the hardness and wear resistance of the roll, heat treatment is required. Common heat treatment processes include quenching and tempering. Quenching is to heat the manufactured roll to a high temperature state, and then to produce a hard phase structure on its surface by rapid cooling. Tempering is to heat the quenched roll to a low temperature state, and then balance the structure by slow cooling to improve its toughness and strength.
Machining: Machining is the last step in the manufacturing of rolls, including roughing, precision machining and grinding. In roughing, it is necessary to cut, mill and drill the roll after casting. In precision machining, various shapes and sizes of rolls need to be manufactured by turning, grinding, etc. Finally, the precision and finish of the roll surface are improved by grinding.
Quality inspection: Quality inspection of the manufactured roll, including size, shape, surface finish and other aspects of the test to ensure that it meets the requirements.
Different manufacturing processes have different effects on the properties of rolls. For example, the use of heat treatment process can improve the wear resistance and hardness of the roll, but its toughness and strength will be reduced. Therefore, in actual manufacturing, it is necessary to make a reasonable selection and combination according to the use conditions and performance requirements of the roll.
Which grinding wheel is selected for the grinding of the roll?
Since different kinds of rolls are made of different materials, we still choose the grinding wheel according to the material of the workpiece to be processed.
For example, grinding forged steel, cast steel, cast iron, high-speed steel roller, we can use corundum or CBN grinding wheel. Grinding gold, non-metal such as ceramic, rubber roller, we use silicon carbide or diamond grinding wheel. The specific choice of grinding wheel and the choice of granularity hardness of grinding wheel can refer to the basic principles of grinding wheel selection shared before or consult us .
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