A method to analyse of roll bending force effect rate in 4-high hot strip mill

A method to analyse the crown effect rate of hot strip was developed successfully by using influence coefficient method. The effect of the roll bending force effect rate in hot strip rolling was investigated in details. Results show that the roll bending force effect rate decreases significantly with the increase of strip width, the difference between the roll bending force effect rate and its base value increases with the reduction, unit width rolling load and work roll diameter. For the strip width 1.85 m, when reduction of 10 mm, unit width rolling load of 15 kN/mm and work roll diameter of 760 mm., the errors to calculate the strip crown base on a base value of the roll bending force effect rate reach 4.6 mum, 6.6 mum and 19.275 mum respectively. However, based on the developed roll bending force effect rate model and the determined relevant coefficients of a six power polynomial expression, the difference between the results obtained from the developed model and the theoretical calculation is 2.5 um when strip width is 1.85 in, so the calculation accuracy for strip crown can be improved significantly.