中文摘要：

对锥形方管无模拉伸进行了实验。研究了各种工艺参数对管锥形方管外形、断面形状变化的影响,分析了方管无模拉伸时断面圆化程度的影响因素及影响规律。结果表明,方管拉伸断面形状膨胀率随着拉伸变形宽度的增大而减小,壁厚较大时,断面形状膨胀率较小,当壁厚和变形宽度都比较大时,几乎不产生膨胀现象;采用无模拉伸的方法可以加工带有一定锥度的锥形方管,锥管角精度在1.0%以内,加工后锥形方管的轮廓与控制曲线的计算结果一致性很好。

英文摘要：

The tapered square pipe dieless drawing experiment was carried out. The influences of various process parameters on the shape and cross section change of the tapered square pipe were studied. The influence factors and law of section circular degree in square pipe dieless drawing were analyzed. The results show that the tensile cross-section shape expansion rate of the square pipe decreases with the increase of the width of tensile deformation. When the wall thickness is larger, the cross-section shape expansion rate is smaller. When wall thickness and deformation width are relatively large, the expansion phenomena is almost no. Using the method of dieless drawing can process tapered square pipe with a taper range,and precision of taper angle is within an error of 1.0%. The tapered profile of pipe after processing and calculating results of the control curve are good consistency.