Design and shape control technology of asymmetric universal crown temper mill

Abstract

The conventional universal crown mill (UCM) temper mill cannot be controlled well for asymmetric high-order complex wave shapes; thus, a novel type of asymmetric universal crown temper mill (AS-UCM) was designed, which was configured for asymmetric bending of the work roll and intermediate roll, as well as asymmetric axial shifting of the intermediate roll. The corresponding shape control technology was established. Taking the typical production process as an example, the present study quantitatively analysed the control effect of AS-UCM and the ordinary UCM temper mill on asymmetric high-order complex wave shapes. Moreover, the related technology was commercially applied to the 750 mm AS-UCM with great economic benefits.

Detection and evaluation mechanism of cold rolling strip edge shape

“…According to the above shape control mechanism, the shape control is actually to continuously control the lateral distribution of roll gap for adjustment of strip metal flow law which is very important to improve the shape control accuracy [1–3,10]. For the large width–thickness ratio cold rolling strip, it must combine the strip metal deformation model with the elastic deformation model of roll system to complete the coupling calculation of the lateral thickness of strip and the theoretical tensile stress respectively. where is the pre-setting value of initial roll gap, is the axis displacement of work roll, is the roll profile of work roll, is the sum of rigid displacements of the upper backup roll and the lower backup roll, is the average value of front tensile stress, is the elastic modulus, is the Poisson ratio, , , are respectively expressed as strip thicknesses at the entrance and the exit of mill and their average values, , are the entrance length of strip and its mean value respectively, is the lateral displacement of strip, B is the strip width.…”

“…In the production processes of the electrical steels, the automobile panels, the home appliance boards and other high-end cold rolling strips, the shape index directly affects the current rolling process, the strip quality parameters and the subsequent craft of cold rolling strip, especially shape states on the edge portions are far from ideal [1][2][3]. Over the years, the edge wave of large width-thickness ratio strip on both sides has become one of the thorny problems which always trouble almost all steel companies.…”

“…According to the above shape control mechanism, the shape control is actually to continuously control the lateral distribution of roll gap for adjustment of strip metal flow law which is very important to improve the shape control accuracy [1][2][3]10]. For the large width-thickness ratio cold rolling strip, it must combine the strip metal deformation model with the elastic deformation model of roll system to complete the coupling calculation of the lateral thickness h i of strip and the theoretical tensile stress s 1i (y) respectively.…”

Numerical analysis on flatness adjusting performance of hot wide strip temper mill with small-diameter work rolls

“…Song et al [7] studied the effect of roll wear on the strip shape. Bai [2] studied the adjusting methods about the high-order flatness defects of the UCM rolling mill. The above research is meaningful, but the L/D ratios of the studied temper mills are limited from 3.00 to 4.50, which are not suitable to help the wide strip temper mill with small-diameter work rolls adjust strip flatness.…”

Influence of roll with cone defect on shape in a six-high mill and its control model

“…In the cold rolling process, the factors that affect the quality of the products include not only the material of strip, but also the process and the equipment of produce. 1,2 Studies on the factors that influence strip shape mainly focus on analysis on the influence of genetic shape, 3,4 bending force, shifting and tilting setting, [5][6][7][8] strip deviation, 9,10 roll profile 11 and mill stiffness 12 on shape. However, studies indicate that major shape problem caused by bad roll grinding and its solutions is in qualitative and lack quantitative research.…”