Rolling mill Rolls and Roll Shop Dec10

Rolling mill Rolls and Roll Shop...

Rolling mill Rolls and Roll Shop Rolls are the main and very costly consumables in a rolling mill. They are used to roll steel in the rolling mill and their performance depend on many factors which include the materials used and the loads to which they are subjected to during service. The roll design is influenced by the limitations applied by the rolling load, the roll strength and the torque available for rolling. In case of flat rolling it is also influenced by the allowance made for roll bending and by cambering of the rolls. The roll design is to take-care the load and torque required for any pass. In addition it must ensure that the physical dimensions and material of the roll are capable of withstanding the heaviest loads arising during the rolling sequence. Another important factor where roll life is concerned is the wear properties of the roll material. Roll materials In the rolling of steels, the material of the rolls is to be capable of withstanding loads which plastically deforms the rolling stock without itself being plastically deformed. In the rolling of hot steel this is not a difficult problem and iron or steel rolls are suitable if they are operated at a temperature considerably lower than that of the rolling stock. Whether iron or steel rolls are used in any particular case depends on the specific duty they have to perform and whether toughness, resistance to thermal cracking or shock loading or hard wearing properties is most important. Rolls can be classified according to the roll materials (Fig 1) and the method of manufacture, the first main subdivision being (i) iron rolls, and (ii) steel rolls. This division depends on the carbon content of the material. In the case of...