变厚度轧制平面形状预测控制多段条元法  

Multi-section strip element method for surface shape prediction and control of variable thickness rolling

作　　者：杨实禹 刘宏民 王东城[1,2] 王国栋 曹晓峥[1] 王宁 YANG Shiyu;LIU Hongmin;WANG Dongcheng;WANG Guodong;CAO Xiaozheng;WANG Ning(National Engineering Research Center for Equipment and Technology of Cold Strip Rolling,Yanshan University,Qinhuangdao 066004,Hebei,China;State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,Hebei,China)

机构地区：[1]燕山大学国家冷轧板带装备及工艺工程技术研究中心,河北秦皇岛066004 [2]燕山大学亚稳材料制备技术与科学国家重点实验室,河北秦皇岛066004

出　　处：《钢铁》2024年第8期94-103,共10页Iron and Steel

基　　金：国家自然科学基金资助项目(U21A20118)。

摘　　要：纵向变厚度轧制是实现轧制产品轻量化、低损耗的有效技术手段。与常规轧制不同,纵向变厚度轧制过程中辊缝连续变化,导致轧制力、摩擦力、变形区长度等重要轧制参数随之改变,形成了非稳定的轧制状态,使轧后平面形状预测与控制更加困难。为解决变厚度轧制过程的平面形状预测难题,提出一种多阶段稳态化处理方法,将变厚度轧制区沿纵向划分为多个轧制阶段,各阶段近似为稳定轧制状态,使变厚度轧制平面形状预测问题转化为多阶段等厚稳定轧制的平面形状预测问题。再将各稳定轧制阶段沿横向划分为多个条元,根据条元变分法原理,将各条元节线的横向位移作为待定参数列出变形区内形变功率函数,根据能量趋小原理和变分法计算得到各条元节线轧制出口横向位移函数。再通过对各稳态轧制阶段整体进行变分计算,可得到条元节线轧后横向位移值。提出以条元边界的中点为平面形状特征点,将边部条元的特征点按稳态轧制阶段的划分顺序进行排列,可组成边部平面形状特征数列,实现对轧件边部形状的预测。基于金属体积不变原理,根据各条元的宽展和厚度可计算得出各条元的轧后纵向延伸值。将各阶段条元的纵向延伸按顺序排列并进行求和,得到各同位条元纵向长度。根据变形区内前后滑区金属流动特性,将变厚度轧制的轧后条元纵向长度分布转化为端部平面形状特征数列,实现轧件端部平面形状的预测。通过试验验证了此方法的正确性与可行性。Longitudinal variable thickness rolling is an effective technical means to achieve light weight and low loss of rolled products.Different from conventional rolling,the rolling gap changes continuously during longitudinal variable thickness rolling,resulting in the change of rolling force,friction force,length of deformation zone and other important rolling parameters,forming an unstable rolling state,which makes it difficult to accurately predict the plane shape of rolled parts.In order to solve the problem of plane shape prediction in the rolling process of variable thickness,a multi-stage steady-state processing method is proposed.The variable thickness rolling area is divided into several rolling stages along the longitudinal,and each stage is approximately stable rolling state,so that the plane shape prediction problem of variable thickness rolling is transformed into the plane shape prediction problem of multi-stage constant thickness rolling.Each stable rolling stage is divided into several strip elements along the transverse.According to the bar variation method,the transverse displacement of each strip element line is listed as the undetermined parameter in the deformation power function in the deformation zone.According to the principle of energy minimization and variational method,the transverse displacement function of rolling outlet of each element can be calculated.Then,the transverse displacement of the strip elements line after rolling can be obtained by the whole variational calculation of each steady rolling stage.It is proposed that the midpoint of the edge element is the feature point of the plane shape,and the feature points of the edge element are arranged according to the division order of the steady rolling stage,which can form the feature series of the plane shape of the rolled piece.Achieve the prediction of the edge shape of the rolled piece.Based on the principle of metal volume invariance,the longitudinal extension of each element after rolling can be calculated according to the width

关 键 词：轧制 变厚度 平面形状 条元变分法 纵向长度差 

分 类 号：TG335[金属学及工艺—金属压力加工]