Effect of Width-to-Thickness Ratio and Thickness Profile Changing on the Critical Instable Shape During Cold Strip Rolling

• Published in: Shanghai jiao tong da xue xue bao Vol. 21; no. 4; pp. 411 - 418
• Main Author: 宋蕾 沈明钢 杨利坡 王军生 陈雪波
• Format: Journal Article
• Language: English
• Published: Shanghai Shanghai Jiaotong University Press 01.08.2016
• Subjects: Architecture; Cold rolling; Computer Science; Coupling; Elastic sheets; Electrical Engineering; Engineering; Life Sciences; Materials Science; Mathematical models; Rolls; Stability; Strip; Strip steel; width-to-thickness ratio; TG 335.5; A; cold rolling strip; sec flow rate equal; lateral thickness difference
• ISSN: 1007-1172; 1995-8188
• DOI: 10.1007/s12204-016-1740-1

Based on the volume constancy with equal flow-per-second and elastic sheet stability theory, a coupling relationship among lateral thickness difference, width-to-thickness ratio of cold rolling strip steel under ideal and actual working conditions, and shape is concluded according to the comprehensive influence principle of various factors on the critical instable shape analyzed in-depth. Firstly, the influence model under actual working condition is developed by referring to the basic relationship between laterM thickness difference and shape under ideal condition. The test results prove that for thin strips with thickness below 0.3 mm, their lateral thickness differences have significant effect on the shape. After and width-to-thickness ratio on the critical instable then, the combined influence of lateral thickness difference shape is concluded according to the elastic sheet stability model, with the synthetic effect of these three factors analyzed. Test data indicate that for cold rolling strip steel with width-to-thickness ratio above 3 000, the critical instability stress difference decreases significantly. Actual measurements are conducted on the lateral thickness differences of two rolls of typical strip manufactured by a six-high cold mill, with the influence law of lateral thickness variation and width-to-thickness ratio comprehensively investigated. It is demonstrated that during the production of ultrathin strip steel with different width-to-thickness ratios, the loading roll shapes should be fine adjusted according to the lateral thickness difference of input strips. Therefore, the variation of lateral thickness difference of output strips can meet the requirement of shape stability, so as to obtain fine shape.