Development of New Back-Up Roll for Strip Shape Control

형상제어를 위한 새로운 보강롤의 개발

  • 이원호 (POSCO 기술연구소 계측제어연구그룹)
  • Published : 2003.02.01


Most of shape defects in steel strip are originated from the structure of rolling mill itself. For instance, strip crown occurs when the work roll is deformed by the bending moment induced on roll chocks. To get rids of the shape defects, it is necessary to increase the stiffness of rolling mill. The structure change of back-up roll is one of alternative ways to increase the mill stiffness without facility revamping from 4 high mill to 6 high mill. In this research work, the new back-up roll was developed and can be used in any type of 4 high mill to reduce the strip shape defects. The developed back-up roll consists of sleeve, arbor and phase angle adjusting system for arbor. The circumference of arbor is specially machined to adapt the strip width change during rolling. The experimental cold rolling test was done to prove the effectiveness of newly developed back-up roll. The experimental rolling results show that the new back-up roll has more powerful performance in reducing the shape defects than conventional back-up roll. It was also found that the new back-up roll has higher stability for shape control. In addition to, the only sleeve surface needs to be reground and changed in most cases, so that the maintenance cost can be greatly reduced.


Steel Rolling;Crown;Wave;Strip Shape Control;Back-up Roll


  1. Feldmann, 1984, 'Strip-Rolling Method and Apparatus,' United States Patent 4,479, 374, pp. 1-14
  2. Yasuda, K. and Shida, S., 1980, 'Simulation of Shape Control in Cold Tandem Mill,' Journal of the JSTP, Vol. 21, No. 230, pp. 225-233
  3. Morel, M. and Bosch, M., 1992, 'Shaperoll Actuator-Results of Hot and Cold Mill Applications,' Iron and Steel Engineer, April, pp. 74-77
  4. Tomizawa, A., 1994, 'Recent Applications of The Variable Crown Roll,' METEC congress 94, Vol. 2, pp. 289-294
  5. Finck, R., 2000, 'Developments in Cold Rolling Mills for Aluminum and Steel,' MTP International, pp. 40-51
  6. 日本塑性加工學會 編, 1990, '板壓延,' 塑性加工技術 Series 7, pp. 164-168
  7. 日立製作所, 1976, '壓延機,' 日本特許廳 公開特許公報, 特許昭 51-103058, pp. 1-7
  8. 菱重工業株式會社, 1980, '壓延機,' 日本特許廳 公開特許公報, 特許昭 55-10366,pp. 1-7
  9. Gronbech, 1983, 'Rolling Mill,' United States Patent 4,407,151, pp. 1-10
  10. Tozawa, K., 1986, 'Three Dimensional Analysis of Strip Rolling,' Journal of the JSTP, Vol. 27, No. 300, pp. 81-88
  11. Yukawa, N., 1987, 'Initiation of Buckling of Strip Caused by Internal Stress,' Journal of the JSTP, Vol. 28, No. 314, pp. 251-256
  12. Shiozaki, H., 1969, 'The Calculation of Roll Bending Effects,' Ishikawa-zima-Harima Technical Reports, Vol. 2, pp. 44-50
  13. Stone, M. and Gary, R., 1965, 'Theory and Practical Aspects in Crown Control,' Iron and Steel Engineer, August, pp. 73-83
  14. Sheppard, T. and Roberts, J., 1973, 'Shape Control and Correction in Strip and Sheet,' International Metallurgical Reviews, Vol. 18, pp. 1-18
  15. Ishikawa, T., 1980, 'Three Dimensional Analysis for Rolling Taken Elastic Deformation of Rolls into Consideration,' Journal of the JSTP, Vol. 21, No. 237, pp. 902-908
  16. O'connor, H. and Weinstein, A., 1972, 'Shape and Flatness in Thin Strip Rolling,' Journal of Engineering for Industry, November, pp. 1113-1123