Simulation of Production Processes for Tubes, Long and Forged Products

Transcription

1 Simulation of Production Processes for Tubes, Long and Forged Products

2 SIMULATION OF PRODUCTION PROCESSES Simulation of Production Processes for Tubes, Long and Forged Products Within SMS group s R&D department the team of Metal Forming Simulation (RDLF) focusses on the simulation of production processes for tubes, long and forged products. SMS group gained over twenty years of experience in this field of simulation. A wide variety of production processes, from metal forming (i.a. rolling, forging) through finishing (i.a. straightening, expanding) to fully coupled microstructure simulations, as well as complete process chains are simulated. To achieve the most truthful reproduction of the real process and to maintain practical relevance, most projects are carried out in close cooperation with engineers of the corresponding product division s technology department. By that, the set-up of the simulation models benefit from both, the expertise in the field of simulation and computer aided engineering (CAE) of the R&D department as well as the process know-how and practical experience of the product division s technologists. Simulations by RDLF are not only for internal product divisions but are provided as a service for customers as well. Objective Model set-up under consideration of numerous physical effects Enhancement of process comprehension Digital test field : - replacement of costly series of tests by simulations with variable parameters - influences of different parameters can be analyzed separately Process optimization: - saving of raw material - saving of energy - optimization of process chains - optimization of product properties (e.g.: residual stress, strain distribution, hardness, microstructure, etc.) Analysis of error and failure analysis: - mold filling - overlap - failure (fracture or crack formation) Activities Simulation of production processes for tubes, long products and forgings with the aid of numerical (FEM) and analytical models Process simulation coupled with microstructure simulation to predict the grain structure (i.e. grain size, recrystallized fraction) and mechanical properties of the product Development of analytical models and their implementation in technology software Model validation by on-site measurements or laboratory experiments Further development of FEM-Software e.g. by implementation of real machine kinematics in numerical models Research projects with partners and institutes, e.g.: - Cluster Advanced Metals And Processes (AMAP): modelling of the crystalline structure in forming processes - German Forging Association: Mannesmann effect SMS materials database Representation at conferences and trade fairs Structural optimization of parts to be produced by additive manufacturing (AM) as well as numerical analysis of the AM process itself 2

3 Software resources Simufact.forming, including licenses for special features for open die forging, ring rolling as well as parallel computing Marc/Mentat Intel-Fortran, C++, Python Creo and AutoCad Hardware resources Multiple powerfull servers for computing (solving) with SuSe-Linux operating system Shared network filesystem Coupling between SuSe-Linux network and Windows network Multiple powerfull desktop computers for pre- and post-processing Examples Ring and wheel rolling: process chain simulation of a wheel forging and rolling line consisting of pre-forming in two stages, wheel rolling, dishing and final punching. Forging plants: Investigation of the cavity closing behavior during radial forging of polygonal ingots to round crosssections. Electric resistant welded tubes plants: roll forming of ERW tubes including breakdown and idle passes, strip edge bending, lineal guiding, fin-pass and squeeze passes as well as final sizing passes. Bright steel plants and finishing lines: bar and tube drawing as well as two-roll straightening (bars) and cross-roll straightening (tubes). 3

4 SIMULATION OF PRODUCTION PROCESSES Forging Closed die forging Objective Process design and press lay-out: Calculation maximum press force Study material flow to avoid underfilling, overlapping Optimization of pre-form geometry Reduction of burr area Process Eccentric press VEPES F max = 140 MN - R crank = 260 mm - L rod = 2600 mm - n = 36 rpm Material: 42CrMo4 (1.7225) ε plastic Analysis 3d fully coupled thermo-mechanical Steering knuckle (stub axle) Results Material flow Press force Die filling ε plastic Crankshaft 4

5 Open die forging Objective: Analysis of the core deformation Calculation of maximum press force Optimization of pass schedules Investigation of the cavity closing behavior Simulated open die forging processes, i.a.: Radial forging Cogging Isothermal forging Multi-directional forging Tube forging Process (example 1): Machine: open die forging press ESR-ingot: - OD = 360 mm - L = 1500 mm octagonal bar: - S = 480 mm - L = 800 mm Material: X40CrMoV5-1 (1.2344) Process (example 2): Machine: radial forging press SMX Ingot: - OD = 416 mm - ID = 246 mm - L = 2030 mm Final tube: - OD = 300 mm - ID = 213 mm - L = 5115 mm Material: 42CrMo4 (1.7225) T in C ε plastic Example 1 Example 2 5

6 SIMULATION OF PRODUCTION PROCESSES Ring rolling & axial closed-die rolling Ring rolling Objective Feasibility study and process control optimization for new ring geometry Process Machine: RAW 100(125)/100(125)-2000/500 Billet (cold): - OD = 412 mm - WTH = 141 mm - H = 150 mm Ring (cold): - OD = 634 mm - WTH = 82 mm - H = 125 mm Material: 31CrMoV9 (1.8519) Analysis 3d fully coupled thermo-mechanical Results Material flow Global forces, drive torques Local strain, temperature, stress Simulation results are used for: Design of new machines, e.g. largest RAW worldwide Technological development of ring rolling process Current developments: Coupling between process control and FEM Programming of user-subroutines (e.g. output of technological results) Increasing precision of models Reduction of calculation time ε plastic

7 Axial closed-die rolling Objective Feasibility study and process development of a compressor disc Process Machine: AGW /125 V Billet (hot): - OD = 175 mm - H = 65 mm Disc (hot) - OD = 300 mm - H = 30 mm Material: Ti6AlV Results Material flow Die filling Rolling forces and drive torque ε plastic

8 SIMULATION OF PRODUCTION PROCESSES Tube rolling and finishing Cross roll piercing wall-thickness Objective: Detailed analysis of wall-thickness during cross roll piercing process Process Billet (cold): - OD = 270 mm Hollow bloom (cold): - OD = 308 mm - WTH = 26.5 mm Material: 42CrMo4 (1.7225) upper roll billet Diescher disc lower roll cross section Analysis 3d fully coupled thermo-mechanical Results Material flow Global forces, drive torques Local strain, temperature, stress Summary of global results Exit velocity = 2.5 entry velocity Roll force = F R Plug force = 0.56 F R Force Diescher disc = 0.15 F R ε plastic FE-model wall-thickness, in mm

9 Cross roll piercing - hollow bloom burr formation Objective: Simulation of the hollow bloom burr formation and the effect of billet tail center punching during piercing Process Billet (cold): - OD = 100 mm Hollow Bloom (cold): - OD = 100 mm - WTH = 10 mm Material: St37-2 (1.0037) Analysis 3d fully coupled thermo-mechanical Results Material flow Global forces, drive torque Local strain, temperature, stress Good agreement between simulation and field experiment at cross roll piercing mill, see below The metal forming simulation provided a key contribution in the development of a solution to avoid burr formation. Amongst others it provided: - the possibility to try out different solutions and geometries to avoid the burr formation; digital test field - detailed material flow analysis - the effect of the different solutions on the tools (forces, drive torque, contact pressure, etc.) Without billet tail center punching: Burr at hollow bloom end Simulation Rolling With billet tail center punching: Optimized tail center punch geometry No burr at hollow bloom end Simulation Rolling 9

10 SIMULATION OF PRODUCTION PROCESSES Process chain with microstructure simulation Objective Modelling microstructure evolution of hot forming processes Prediction of product properties Design new and optimize existing process chains Project plan Parametrization of microstructure model Coupling between FE-model and microstructure model Validation of software packages based on measured data Exemplary process chain Turbine disc as a component of a jet engine Material: Inconel 718 Block weight: 100 kg Final diameter: 540 mm Final weight: ca. 15 kg Source: Leistritz Turbinentechnik GmbH Initial geometry After upsetting After piercing After 1 st ring rolling After 2 nd ring rolling After 3 rd ring rolling Final geometry after forging 10

11 Validation of FE-models of the industrial process chain: grain size distribution over the component cross-section Result after 1 st ring rolling and cooling to room temperature grain size, in µm inside outside Result after final forging and cooling to room temperature grain size, in µm Conclusion Tendencies are displayed correctly Local deviations R&D project in cooperation with: Simufact Engineering GmbH Institute of Metal Forming of the RWTH Aachen 11

12 SMS group GmbH Ohlerkirchweg Mönchengladbach, Germany Phone: Telefax: X-364E SMS group GmbH Published on Circulation 300 Printed in Germany Ky The information provided in this brochure contains a general description of the performance characteristics of the products concerned. The actual products may not always have these characteristics as described and, in particular, these may change as a result of further developments of the products. The provision of this information is not intended to have and will not have legal effect. An obligation to deliver products having particular characteristics shall only exist if expressly agreed in the terms of the contract.