The main working parts and tools of the rolling mill to produce continuous plastic deformation of metal. The roll is mainly composed of three parts: roll body, roll neck and shaft head. The roll body is the middle part of the roll that is actually involved in rolling metal. It has a smooth cylindrical or grooved surface. The roller neck is installed in the bearing and the rolling force is transmitted to the frame by the bearing seat and the holding down device. The shaft head of the transmission end is connected with the gear seat through the connecting shaft, and the torque of the motor is transmitted to the roll. Rolls can be arranged in two, three, four or multiple roll forms in the mill frame.
Roll classification
There are many kinds of roll classification methods, mainly:
(1) According to the product type, there are strip rolls, steel rolls, wire rolls, etc.;
(2) According to the position of the roll in the rolling mill series, there are cutting rolls, rough rolls, finishing rolls, etc.;
(3) According to the function of the roll, there are scale-breaking rolls, perforating rolls, flattening rolls, etc.;
(4) According to the roll material divided into steel roll, cast iron roll, carbide roll, ceramic roll, etc.;
(5) According to the manufacturing method, it is divided into casting rolls, forging rolls, surfacing rolls, and insert rolls;
(6) According to the state of the rolled steel, there are hot rolls and cold rolls. Various classifications can be combined accordingly to make the roll have a more clear meaning, such as the centrifugal cast high chromium cast iron work roll for hot rolled strip steel.
Roll selection
The commonly used roll materials and uses are shown in the table. The performance and quality of a roll generally depends on its chemical composition and manufacturing method and can be assessed by its organizational, physical and mechanical properties and the type of residual stress present inside the roll (see Roll Inspection). The use effect of the roll in the rolling mill not only depends on the material and metallurgical quality of the roll, but also depends on the use conditions, roll design, operation and maintenance. Different types of rolling mill roll conditions are very different, causing differences in the factors are:
(1) Rolling mill conditions. Such as rolling mill type, rolling mill and roll design, pass design, water cooling conditions and bearing types;
(2) rolling conditions such as rolled varieties, specifications and deformation resistance, pressure and temperature systems, production requirements and operations;
(3) Requirements for product quality and surface quality.
