中厚壁钢管三辊轧制内裂原因分析

Investigation of Causes of Medium Wall Steel Tube Internal Cracking Occurring in Three-roll Rolling Process

在三辊轧管机上采用不同的变形量进行轧制对比实验,分析了三辊轧制过程中产生的切向、轴向剪切应力及塑性弯曲变形时产生的切向、轴向拉应力对内裂的影响。实验结果表明:在其他工艺条件相同时,三辊轧制的变形量超过一定值时,钢管内表面金属破裂。针对中厚壁钢管内表面纵裂纹形成的主要原因,提出了解决措施。

With the comparative test rolling operations of the three-roll pipe mill with different deformation amounts, the elements responsible for the internal cracking of the material are analyzed, including the tangential and axial shearing stresses produced during the three-roll rolling process and the tangential and axial tensile stresses produced during plastic bending deformation process. The experiment result shows that with all the other process conditions remaining unchanged, when the deformation amount by the three-roll rolling exceeds a certain value, the internal metal cracking on the inner surface of the tube takes place. Following the main causes of the longitudinal cracking on the inner surface of the medium-wall steel tube, relevant actions are proposed.