Seamless steel tubes are produced by cold drawing technology, utilizing multiple drawing sequences with intermediate heat treatment. Five sequences technology of cold drawing tubes is currently investigated for grade E235 from Ø31,8 mm, x 2,6 mm to Ø6 mm x 1 mm.
Numerical simulation based on the finite element method was used for preliminary material flow analysis. The results from numerical simulation were compared with values from technological exams by selected physical variables. The comparison of dimensions with values drawing forces of numerical simulations and experiments showed a good agreement. Therefore, we can consider our numerical model a validated one.
In heat exchangers, cold drawn seamless tubing with straight internal rifling brings several benefits to the heat transfer process. However, the production of such tubes by cold drawing brings a considerable challenge in meeting strict dimensional criteria on a rifling geometry.
Optimization of the whole production process naturally involves a numerical simulation of cold drawing, saving time and costs of pre-production plant trials. The key aspect of multi-rifled tube production is the proper creation of internal rifling via gradual filling of plug grooves during drawing.
It is this mechanism where the benefit of numerical simulation steps in, providing us with a qualitative and quantitative estimation of important state variables. In this article, four hollows have been compared as an input feedstock for cold drawing multi-rifled tubes.