A Study on the Control of Spring Back for the Precision Forming of the Steam Generator Helical Tube

The spring back taking place after the coiling process of steam generator tube leads to the dimensional inaccuracy. In order to reduce the spring back, tension force was applied to the one end of the tube during forming. In this work, parametric study using FEM was performed to find the appropriate magnitude of tension force. The force that induces minimum spring back was found by simultaneously taking account if spring back amount, cross-sectional ovality, and thickness of the tube wall after deformation. In addition, stress relieving by heat treatment was also simulated as an alternative to the former method. The latter was found to be more effective under the given constraints.

나선형 증기 발생기 튜브의 정밀성형을 위한 스프링백 제어 연구