二辊斜轧延伸9Cr-1Mo钢厚壁管内表裂纹形成倾向性模拟研究

A Study of Simulation on Tendency of Inner Surface Crack of Steel 9Cr-lMo Heavy Wall Pipe Elongated by Two-High Cross Piercing Process

借助于商用有限元软件MSC.SuperForm,对φ485 mm×73 mm大口径厚壁9Cr-1Mo钢管二辊斜轧延伸过程进行了3D热力耦合模拟;采用Oyane韧性断裂准则分析了轧件损伤场及钢管内表裂纹的倾向性,发现钢管内表邻近芯棒接触区存在破裂高危带。研究了轧辊入口锥角对轧件损伤场的影响,结果表明,轧辊入口锥角由3.0°增至5.0°时,轧件最大损伤特征由0.520 7降至0.3544,发生内表裂纹的倾向性降低。

The 3 D thermo-mechanical simulation on two-high cross piereing elongating process of steel 9Cr-lMo Ф485 mm × 73 mm large size heavy wall pipe has been carried out by using commercial element software MSC. SuperForm. The damage field of rolling piece during elongation process and the tendency of inner surfaee crack of steel pipe are analyzed by using Oyane criterion for ductile fracture. It is found that there is a high dangerous erack band in internal surface of steel pipe adjoining contact zone with plug. The influence of roll entrance eone angle on damage field of rolling piece is studied. Results show that as the roll entrance cone angle increases from 3.0° to 5.0° the maximum damage characteristic value decreases from 0. 520 7 to0. 354 4 and the tendency of inner surface crack reduces.