The high-speed steel roller ring is evenly distributed along the roller ring according to thermal stress and assembly stress, so any section of the roller ring can be selected for stress superposition. Regarding the stress caused by the rolling force, tensile stress is generated in the inner layer of the AB section and compressive stress is generated in the outer layer, while compressive stress is generated in the inner layer and tensile stress is generated in the outer layer of the CD section.
When performing stress superposition on the roll ring, the thermal stress generated along the axial direction of the roll ring is not considered due to the small length of the roll body. At the same time, the rolling pressure also exerts radial stress on the roll ring. Since the main influence on the service life of the roll ring is tangential stress, the influence of radial stress is also ignored.
During the rolling process, the roll ring is affected by rolling stress, thermal stress and assembly stress. When the assembly stress remains unchanged, in order to ensure the safety of the roll ring, the rolling stress and thermal stress should ensure the allowable value of the strength of the roll ring. For roll sleeves of certain materials, the allowable values are constant values. Therefore, based on the allowable values, the rolling conditions under different thermal stresses and rolling stresses can be obtained, that is, different temperature differences between the inside and outside of the roll ring can correspond to different rolling pressures.
1. The roll ring roller is affected by assembly stress, thermal stress and rolling stress during the rolling process. The stress on the roller ring is the algebraic sum of the stress values along the section;
2. During the rolling process, the tangential tensile stress on the inner diameter of the roll ring is large. The use of composite material roll rings will help improve the service life of the rolls. The inner layer can be made of cast steel to improve strength and toughness, and the outer layer can be made of cast iron to improve hardness and wear resistance;
3. Under certain assembly stress, on the premise of ensuring the strength of the roll ring, the thermal stress and rolling stress change trends are opposite. Therefore, when the temperature difference between the inner and outer layers of the roll ring is large, the rolling pressure should be appropriately reduced;
4. Parameters such as roll ring temperature difference and rolling force should be stable during the rolling process. If the above parameters fluctuate too much, the roller ring will be easily damaged when the temperature difference and rolling force increase.
5. The assembly accuracy of the roller ring should be ensured, otherwise the roller ring will be easily damaged due to the increase of local stress and other stresses.