Page 20 - ITAtube Journal 1 2019

Technical Papers
QFX simulations
Simulation of piercing processes in a helical rolling mill using the QForm software
Vladislav Mikhailovich Maximov (born 1980),
a lead specialist of the Engineering & Technology Center of the JSC Vyksa Steel Works.
Address:
6/60 Centralny microdistrict, Vyksa, 607060. Contact phone: +7-83177-95461, +79103963362. E-mail: maksimov_vm@vsw.ru
Oleg Stanislavovich Khlybov (born 1961),
Head of the mathematical modeling department of Engineering & Technology Center of the
JSC Vyksa Steel Works.
Address:
5/12 Krasnye Zori lane, Vyksa, 607060.
Contact phone: +7-83177-95417, +79163531047. E-mail: hlybov_os@vsw.ru
Cross roll piercing is a process for producing hollow tubes from initially cylindrical billets. Typically, a two-pass process is used in cross roll piercing, but with the use of computer simulation it may be possible to identify a one-pass procedure that reduces machine time and increases productivity. QForm is a commercially available finite element code that can be used to handle large-deforma- tion forming processes. This paper details the development of a QForm computer simulation of a one-pass piercing process, and compares the sim- ulation results with results obtained experimen- tally. This approach to the development of the production process can reduce try out costs when designing new piercing regimes in order to imple- ment them at the present production facilities.
Introduction
Currently, the finite element method (FEM) is widely used by industrial plants to simulate manufacturing operations, including metal forming operations. For forming processes that involve large contact forces between workpiece and tooling, the accuracy of the predicted stresses and strains is typically increased when the tooling is considered to be deforma- ble. As such, finite element codes that can handle
deformable tooling have wider application. Using such systems makes the development of new prod- ucts easier and reduces costs, allows forecasting out-of-specification conditions and identification of possible risks in the forming operations.
The QForm software package is a finite element code used in JSC VMZ for solving a wide range of tech- nological problems including the cross roll piercing process. The software was created by QuantorForm Ltd., a Russian company that has been developing software for computer modelling of metal forming processes since 1991. Their products are being used in various branches of industry all over the world [1].
QFORM uses a Lagrangian mesh for predicting the deformation of deformable bodies. The inclusion of deformable tools in the simulation should increase the accuracy of the predictions compared to simu- lations where the tools are considered to be rigid. Several authors have reported that QFORM predic- tions for metal forming process agree favourably with practical data [2, 3].
Finite-element model of cross roll piercing process
The simulation process in QForm may generally be divided into three stages.
At the first stage, three-dimensional models of the tools and the workpiece are created in an appro- priate CAD-system and stored in IGES or STEP file formats. The CAD data is read into QFORM which can be used to further prepare the model by:
1. initially positioning the solid bodies relative to each other
2. eliminating any existing geometric defects
3. meshing the models
4. specifying the axes and the rotation directions of rolls, rollers, etc.,
5. setting symmetry properties if any
For this work, we used Compas 3D package as a CAD system for constructing the geometry of all the bodies involved (see Figure 1).
ITAtube Journal No1/February 2019
20