Model Building of Backup Roller Diameter Effect Rate in 4-High Mill

Software for calculating the strip profile in 4-high hot rolling mill was developed using influence coefficient method.Regularity of backup roller diameter effect rate was studied systematically using the software. The results show that backup roller diameter effect rates decrease versus the increase of strip width, increase significantly versus theincrease of backup roller diameter and obscurely increase versus the increase of reduction. The difference betweenbackup roller diameter effect rate and it is reference value increases versus strip width increasing. When backuprollers diameter is set to be 1.64 m and strip width is 1.85 m, the error of strip profile calculated using the model of backup roller diameter effect rate reference value will be 3.55 μm. Based on the results, reference values of roller diameter effect rate and six power polynomial fitting coefficients of modification coefficients were determined considering coherent parameters. The high precision model of backup roller diameter effect rate was established.When the model is used to predict strip profile, the accuracy is less than 5.0μm.