Theoretical and FE analysis for inconel 625 fine tube bending to predict springback

• Published in: International journal of precision engineering and manufacturing 2012-12, Vol.13 (12), p.2143-2148
• Main Authors: Jeong, Ho-Seung, Ha, Man-Yeong, Cho, Jong-Rae
• Format: Article
• Language: English
• Subjects: Engineering; Industrial and Production Engineering; Materials Science
• ISSN: 2234-7593; 2005-4602
• DOI: 10.1007/s12541-012-0284-z

During tube bending, the springback is caused by elastic deformation after unloading. This has an important influence on the precision forming of the bent tube. Springback depends on the material properties (such as the strength coefficient, work hardening exponent and yield strength), the bend radius and geometric ratio of D/t. Inconel 625 alloys have high strength and high work hardening than other metals. The aim of this study is to predict the amount of springback of an inconel 625 fine tube during the bending process. In our study, an elastic-plastic theoretical analysis is presented to predict the bending moment and springback of bend tube with hollow circular section considering the work hardening in the plastic-deformation region. The FE analysis was performed in order to predict the springback in the conditions of a bend angle in the range of 90 ° to 180 °, a friction coefficient in the range of 0.01 to 0.1, and a bend radius in the range of 6.75 to 25.75 mm. When the friction coefficient was increased from 0.01 to 0.1, maximum tensile stress was increased during the tube bending process, and the springback angle was increased after unloading process. The springback angle and final radius of curvature according to the friction coefficient and bend radius was approximated by the quadratic regression. The results may help for prediction and controlling the springback in the bending process of inconel 625 alloy tubes.