方矩管管壁增厚的原因分析

检测发现，在圆变方矩管成型工艺中，管壁均有不同程度増厚现象，并且具有6个特点。指出形成壁厚增量的根本原因是:管坯在孔形变型力作用下，周向长度被压短，形成金属流动而转移到管坯断面上，表现为管壁增厚，内腔变小。同时，提出了控制壁厚增量的思路和方法，并已生产了若干批壁厚增量为0的方矩管。

Discussion on Thickening Reason of Rectangular Pipe Wall Thickness

Wall thickness of rectangular pipe increased at different degree during the process,in which circular pipe was extruded to rectangular pipe and posses 6 characteristics.It pointed out the main reason of wall thickness thickening,circumferential length of pipe bloom was shortened under pass deformation force,formed metal and transferred on pipe bloom surface,so wall thickness of pipe increased and inside diameter of pipe diminished.At the same time,the idea and method of controlling wall thickness thickening were put forward,and several lots of rectangular pipes have been produced which wall thickness had no increment.