Push-bending Process and Forming Quality of Stainless-steel Tubes

¹ Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116085, China
² Science and Technology on Reactor Fuel and Materials Laboratory, Nuclear Power Institute of China, Chengdu 610213, China

^* Corresponding author: gqchen@dlut.edu.cn

Abstract

The push-bending process of stainless-steel tubes was investigated by using the experimental method and finite element (FE) analysis based on the commercial software MSC.MARC. The effects of the processing parameters and the lubricating condition on the forming quality of as-obtained ASTM304 tubes were discussed. The results demonstrated that the experiment results were consistent with the simulation both in deformation behaviour and the stress distribution during the push-bending process, which verified the reliability of the established FE-model. The results also show that the maximum residual stress concentrates in the middle of tubes, the residual strain on both the external side increases firstly, then decrease, and increase again with the increase of the location angel. After the push-bending, the interior wall thickness increases while the exterior wall thickness decreases. When the relative bending radius is larger, smaller variation of wall thickness will be obtained. With the increase of the friction coefficient, the wall thickness thinning rate will decrease. With the increase of the pushing speed, the wall thickness thinning rate decrease a little while the thickening rate increases slightly. When push-bending of the large radius tubes, a good lubricating condition can reduce the wall thickening problem at the intrados, which will ensure a better forming quality. Keyword. Bending, Quality control, Simulation