具有复合组织的不锈钢管周期轧制过程的数值模拟

NUMERICAL SIMULATION OF COLD PILGERING OF STAINLESS STEEL TUBES WITH COMPOSITE STRUCTURE

应用ANSYS软件对具有复合组织的电磁离心铸造1Cr18Ni9Ti不锈钢管的周期轧制过程进行了三维有限元数值模拟.模拟结果表明,管坯轴向塑性越好,在轧制过程中产生的剪切应力σrz和剪切应变εrz越小,管坯变形能力越强.降低工具与管坯摩擦系数,可以减小σrz和εrz.减小管坯外层柱状晶区与内层等轴晶区之间σrz的不连续性,提高管坯的变形能力和成形管材的质量.在电磁离心凝固时适当地加大励磁电流以增加铸管中等轴晶区比例,不但可以提高铸管的力学性能,还可以减小管坯在轧制过程中所产生的σrz和εrz,进而使其轧制变形能力增强,其成形管材质量也得到改善.通过轧制实验验证,模拟结果与实验结果吻合良好.

A 3D finite element method is used to the simulation of cold pilgering process of 1Cr18Ni9Ti stainless steel tubes by using ANSYS software, which are cast by electromagnetic centrifugal casting (EMCC) and of the characteristic of composite structure. Simulation results show that during cold pilgering the better the axial plasticity of tubes, the smaller the shear stress sigma(rz), and the shear strain epsilon(rz), as well as the better the property of rolling deformation. Along with the decrease of the Coulomb friction coefficient not only the sigma(rz), and the epsilon(rz), are decreased, but also the discontinuity Of sigma(rz), between outer columnar and inner equiaxied zone is decreased. Moreover, the property of rolling deformation and the quality of tubes are improved. With the increase of exciting currents, which enlarges equiaxed zone, not only the mechanical property of the tubes is improved, but also the sigma(rz), and the epsilon(rz) are decreased. Moreover, the property of rolling deformation and the quality of tubes are also improved. The simulation results agree well with the experiment.