轧制同轴复合棒材的芯材变形规律  

Core rod deformation principle of rolled coaxial composite bar

作　　者：余伟[1] 熊家泽[2] 雷力齐 王筑生[2] 

机构地区：[1]北京科技大学冶金工程研究院,北京100083 [2]首钢集团贵阳特殊钢有限公司,贵州贵阳550005

出　　处：《钢铁研究学报》2016年第8期33-38,共6页Journal of Iron and Steel Research

基　　金：国家"十二五"科技支撑计划资助项目(2012BAE03B01)

摘　　要：棒材同轴复合时芯材与加工工具不接触,其横截面形状及尺寸精度控制难度大,采用方-椭圆孔型轧制时芯材圆度严重超公差。在建立覆材和芯材变形抗力模型的基础上,利用三维弹塑性热力耦合有限元方法对同轴复合棒材热轧变形过程进行数值模拟。分析了轧制孔型、覆材及芯材外形对轧制后芯材变形和形状的影响,用工业试验对模拟计算结果进行验证。结果表明:轧辊孔型设计对芯材不圆度的影响最明显,覆材及芯材外形是次要影响因素。这是因为方-椭圆孔型系统会导致最终轧件在横截面上的非对称等效累积应变分布,以及导致轧后芯材严重不圆。减少K4孔的轧件压下量,增加K3孔轧件压下量,可以改善方-椭圆孔型中轧件变形的对称性,减少芯材不圆度。The cross-section profile and dimensional accuracy of core rod was hard to control because of no direct contact between the core rod and the forming tools while coaxial composite bar was rolled.The core rod roundness severely deviated from tolerance limits after hot rolled in square-oval grooves.Based on establishment of the deformation resistance models of the clad and core materials,the deformation of coaxial composite bar in hot rolling process was numerically simulated by three dimensional thermal-mechanical coupled elastic-plastic finite element method.The effects of rolling pass design,clad and core contour on deformation and shape of the core material after rolling were studied respectively.The numerical calculation results were verified by industrial rolling experiments.The results show that the influence of rolling groove design on the core ellipticity is remarkable,but the clad and core contours are the secondary factors.It is because that square-oval groove system leads to an asymmetrical accumulative equivalent strain distribution on the cross section of the workpiece and the severe elliptic core after rolling.Deceasing reduction of K4 groove and increasing reduction of K3 groove can improve the core symmetry deformation of the workpiece and reduce its out-of-roundness.

关 键 词：复合棒材 热轧 孔型设计 有限元法 模拟 

分 类 号：TG335[金属学及工艺—金属压力加工]