矩形管冷弯成形的辊花设计及成形规律

摘要

In terms of multi-pass groove rolling characteristics of rectangular tubes in cold roll forming processes,considering the existence of topological equivalence relations between round tube billets and rectangular tubes,a centroid mapping mathematic model was established between them to realize the roll flower design of rectangular tubes in cold roll forming processes.The cold roll forming experiments were carried out on the test mill,and rolled products may meet the GB/T 6728-2002 standard.A simulation model for cold roll forming of rectangular tubes was established based on an e-lastic-plastic finite element method.The regularities of metal flow and longitudinal elongation were re-searched to analyze the formation cause of displacement neutral plane in corners and edges of the tube ends.The distributions of residual stresses of rectangular tubes were researched to determine the easy cracking positions.The results may be expected to provide theoretical basis for the design model of roll flower and forming technology of cold roll forming processes.%依据矩形管冷弯成形的多道次孔型轧制特点，考虑轧前圆管坯与轧后矩形管存在的拓扑等价关系，建立了两者之间的形心映射数学模型，实现了矩形管冷弯成形过程的辊花设计，并进行了轧制实验。轧后产品满足 GB/T 6728-2002的要求。基于弹塑性有限元法建立了矩形管冷弯成形的仿真模型，研究了冷弯成形的金属流动、纵向延伸和残余应力分布，确定了变形过程开裂危险区位置。