Effects of tool–workpiece interfaces friction coefficient on power and energy consumption during the piercing phase of seamless tube production

Abstract

This research analyzes the impact of various friction conditions at the interface of the tube piercing machine tools and Super Cr13 steel workpiece. For this reason, the three-dimensional finite element method (FEM) is employed in the simulation of the tube piercing process. The friction conditions are simulated considering Tresca, Viscoplastic, IFUM and Neumaier models which have been implemented at the Rollers-Billet (RF), Plug–Billet (PF), and Diescher–Billet (DF) interfaces. After testing their performance, Viscoplastic is selected for RF interface, and Tresca for PF and DF interfaces, respectively. Additionally, a friction coefficient range between 0.01 and 0.6 is used for RF, 0.06–0.15 for PF, and 0.1–0.3 for DF. The relation between normal stress, strain, temperature, and quality of pierced tubes is discussed, as well as the connection between the friction coefficient and the energy consumption. The FEM results are validated by actual piercing process data provided by Industry. The results show that the normal stress on billet during piercing increases by increasing friction on RF interface. With increasing friction in PF, both friction power and plastic power increase, while increasing friction in RF lead to a friction and plastic power decrease. According to the results, the minimum energy consumption is recorded at RF = 0.5, PF = 0.06, and DF = 0.1.

Keywords

• Hot piercing process
• Seamless tube
• Energy consumption
• Super Cr13 steel