Determination of the Active Medium Temperature in Media Based Press Hardening Processes

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Welf-Guntram Drossel ◽  
Norbert Pierschel ◽  
Alexander Paul ◽  
Klaus Katzfuß ◽  
Rico Demuth
Keyword(s):  
Active Medium ◽  
Lightweight Design ◽  
Temperature Curve ◽  
Work Piece ◽  
Gas Temperature ◽  
Forming Process ◽  
Element Analysis ◽  
Medium Temperature ◽  
Press Hardening ◽  
Active Media

Safety, lightweight design, and reduction of emissions are terms which are key issues in modern vehicle construction. These challenges can be met by new lightweight design strategies, e.g., by using lightweight materials and high-strength steels as well as innovative forming technologies such as media based press hardening (MBPH). MBPH as a sub-production technique of hydroforming is a tempered internal high-pressure forming process of closed profiles, which this article is about, or sheet metals by gaseous media. Due to the high process requirements (internal pressure up to 70 MPa and temperatures up to 1000 °C), it has not been possible to measure the temperature curve of the active medium in a reliable way until now. The aim of the research project described in this article was to develop an innovative measuring instrument to determine the gas temperature curve with a measuring frequency of at least 1 Hz. Analytical and numerical calculations have indicated that the active medium has a significant influence on the thermodynamic of the forming process. The finite element analysis (FEA) of the heat flow during the forming process has indicated that the influence of the gas on the cooling process of the work piece is about 15% of the total influence of the tool. Consequently, the active medium in media based press hardening processes is an important thermal influencing factor. Experiments have confirmed that it is possible to determine the calculated curve of the gas temperature and maximum temperatures of the active media up to 500 °C. The findings of these studies make a significant contribution to identifying and analyzing the complete temperature balance in tempered active media based forming processes.

Experimental Investigation and Finite Element Analysis on Electromagnetic Compression Forming Processed Aluminum Alloy Tubes

2011 ◽  
Vol 110-116 ◽  
pp. 1706-1710
Author(s):  
Selvam Rajiv ◽  
Karibeeran Shanmuga Sundaram ◽  
Pablo Pasquale
Keyword(s):  
Experimental Investigation ◽  
Finite Element ◽  
Aluminum Alloy ◽  
High Speed ◽  
High Energy ◽  
Work Piece ◽  
Outer Diameter ◽  
Forming Process ◽  
Element Analysis ◽  
Electromagnetic Compression

Electromagnetic forming (EMF) is a high energy rate forming (HERF) process. It is a high speed forming process using a pulsed magnetic field to form work pieces made of metals such as copper or aluminum alloys with high electrical conductivity. The work piece to be deformed will be located within the effective area of the tool coil so that the resulting type of stress during the forming process is determined by the type of coil used and its arrangement as related to the component. Tubular or structural components can be narrowed by means of compression coils or widened by means of expansion coils, where as sheet metal can be deformed by flat coils. In this work, the experimental investigation and simulation of electromagnetic compression forming of aluminum alloy tubes is studied. The aim of the paper was to verify the results from Finite element methods with experimental data. Experiments were conducted on Tubes of outer diameter 40 mm and wall thickness of 2 mm with a nominal tensile strength of 214 MPa. The tube was compressed using a 4 turn helical actuator discharge that can be energied up to 20 kJ. A field shaper made of aluminum was used. A Maximum reduction of 15.85% in diameters were measured. The same problem was simulated in ANSYS using static coupled electromagnetic analysis. The results of the Simulation showed good correlation with experimental results.

Finite Element Analysis of Rolling Process to Locally Thin Metal Strips

2018 ◽  
Vol 920 ◽  
pp. 10-15
Author(s):  
Kuang-Jau Fann ◽  
Che Yi Lin ◽  
Ying Ju Chen
Keyword(s):  
Finite Element ◽  
Steel Strip ◽  
Lightweight Design ◽  
Rolling Process ◽  
Roll Forming ◽  
Speed Ratio ◽  
Forming Process ◽  
Element Analysis ◽  
Finite Element Software ◽  
Roll Forming Process

Because of relative low investment cost on the installation of equipment and extensive product quality with other advantages, roll forming process has been broadly applied to produce profiles from steel strip bands and has gradually replaced aluminum profiles made by hot extrusion. Moreover, a lightweight design is the trend for reducing carbon emissions and waste. Therefore, a lightweight design of structures with local thinning used the roll forming production will make metal profiles more market competitiveness. In this study, the commercial Finite Element software DEFORM is used to investigate the rolling process preparing the metal strips with local thinning feature for the subsequent roll forming process to form a lightweight metal profile. Two kinds of roll configuration are used in this study, namely symmetrical and non-symmetrical. The symmetrical rolling process has the same diameter for the upper and the lower roll, while the non-symmetrical rolling process has different diameter in both rolls. As the process parameters, the roll speed ratio between the upper and the lower roll is used for the symmetrical rolling process, while the distance between the axis of the upper and lower roll is used for the non-symmetrical rolling process. As a result, the rolled thinning feature has its sidewalls flaring outwards, so that it has a narrow bottom and a wide opening. Furthermore, it can be regarded as defect that the thickness of the rolled thinning feature is not thinned enough as required and a raising at the opening is observed. In general, increasing the roll diameter or keeping the speed of the two rolls as the same can have a better thinning result for the symmetric rolling. In the non-symmetric rolling, increasing the roll diameter can improve the thickness, but no significant effect can be found by changing the roll diameter ratio.

Tube Press Hardening for Lightweight Design

2011 ◽  
Author(s):  
Reimund Neugebauer ◽  
Frank Schieck ◽  
Markus Werner
Keyword(s):  
Lightweight Design ◽  
Innovative Technology ◽  
Material Strength ◽  
Original Material ◽  
Heat Management ◽  
Forming Process ◽  
Press Hardening ◽  
Forming Technology ◽  
Process Reliability ◽  
The Media

Press hardening is an innovative technology being applied to meet the growing demands for both lightweight and crash performance qualities. To further increase the lightweight potential, closed profiles are being used. As a result, a method has been developed at the Fraunhofer Institute for Machine Tools and Forming Technology IWU which allows the integration of press hardening of tubes and closed profiles into the media-based forming process. Using this press hardening technology, the original material strength of 500 MPa can be increased to between 1200 and 1900 MPa, depending on the chosen material. The engineering of tube press hardening is more complex than other forming processes, specifically the time dependence in combination with heat management makes it difficult. Therefore the use of FEA is indispensible when dealing with aspects such as heat treatment, the forming process itself, the cooling caused by the gaseous forming media and the general heat management of the tooling. To control and improve the process and therefore the part quality and process reliability, all these factors and their dependencies have to be taken into account. In addition to 22MnB5, other manganese-boron alloyed steels and different heating strategies have been tested. Based on these experiments the process capability was successfully proven and technological limits were obtained. Current investigations are focused on realizing tailored properties thus creating areas with varied strength and ductility in a single part.

Analysis on Temperature Field of Work-Piece during Cross Wedge Rolling

2011 ◽  
Vol 230-232 ◽  
pp. 352-356
Author(s):  
Wen Ke Liu ◽  
Kang Sheng Zhang ◽  
Zheng Huan Hu
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Metal Flow ◽  
Work Piece ◽  
Contact Deformation ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Rigid Plastic ◽  
Finite Element Software ◽  
Deform 3D

Based on the rigid-plastic deformation finite element method and the heat transfer theories, the forming process of cross wedge rolling was simulated with the finite element software DEFORM-3D. The temperature field of the rolled piece during the forming process was analyzed. The results show that the temperature gradient in the outer of the work-piece is sometimes very large and temperature near the contact deformation zone is the lowest while temperature near the center of the rolled-piece keeps relatively stable and even rises slightly. Research results provide a basis for further study on metal flow and accurate shaping of work-piece during cross wedge rolling.

Semi-Enclosed Cold Forging Process Analysis and Progressive Die Design of CPU Fin

2008 ◽  
Vol 575-578 ◽  
pp. 174-179
Author(s):  
Juan Hua Su ◽  
Feng Zhang Ren ◽  
Lei Wang
Keyword(s):  
Production Efficiency ◽  
High Efficiency ◽  
Process Analysis ◽  
Die Design ◽  
Cold Forging ◽  
Forming Process ◽  
Element Analysis ◽  
Whole Process ◽  
Progressive Dies ◽  
Transfer Unit

This paper analyzes the forming process methods of fin used in CPU chip to emit heat. The whole process is blanking, the first forging forming, the second forging (sizing), and trimming. The chamfer design of CPU fin blank is simulated by finite element analysis. The optimized chamfer 1.6 mm is available. Semi-enclosed cold forging of progressive dies is put forward. The newly designed transfer unit is applied, which unifies the merit of high efficiency of the progressive dies and the high material-using ratio of the project die. Quick disassembly structure is designed and pins are used as quick disassembly pins by means of ball bearing bushing. The unique processing of the shearing scrap structure is adopted when designing the inverted trimming dies. Compared with the traditional die, the mechanization and electrization are realized to increase the production efficiency and get highly precise CPU fin.

Measurement and Calculation of Elastic Properties in Low Carbon Steel Sheet

2005 ◽  
Vol 495-497 ◽  
pp. 1591-1596 ◽  
Author(s):  
Vladimir Luzin ◽  
S. Banovic ◽  
Thomas Gnäupel-Herold ◽  
Henry Prask ◽  
R.E. Ricker
Keyword(s):  
Carbon Steel ◽  
Elastic Property ◽  
Elastic Properties ◽  
Steel Sheet ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Forming Process ◽  
Element Analysis ◽  
Wide Range ◽  
Carbon Steel Sheet

Low carbon steel (usually in sheet form) has found a wide range of applications in industry due to its high formability. The inner and outer panels of a car body are good examples of such an implementation. While low carbon steel has been used in this application for many decades, a reliable predictive capability of the forming process and “springback” has still not been achieved. NIST has been involved in addressing this and other formability problems for several years. In this paper, texture produced by the in-plane straining and its relationship to springback is reported. Low carbon steel sheet was examined in the as-received condition and after balanced biaxial straining to 25%. This was performed using the Marciniak in-plane stretching test. Both experimental measurements and numerical calculations have been utilized to evaluate anisotropy and evolution of the elastic properties during forming. We employ several techniques for elastic property measurements (dynamic mechanical analysis, static four point bending, mechanical resonance frequency measurements), and several calculation schemes (orientation distribution function averaging, finite element analysis) which are based on texture measurements (neutron diffraction, electron back scattering diffraction). The following objectives are pursued: a) To test a range of different experimental techniques for elastic property measurements in sheet metals; b) To validate numerical calculation methods of the elastic properties by experiments; c) To evaluate elastic property changes (and texture development) during biaxial straining. On the basis of the investigation, recommendations are made for the evaluation of elastic properties in textured sheet metal.

scholarly journals Flexible Die Design and Springback Compensation Based on Modified Displacement Adjustment Method

2014 ◽  
Vol 6 ◽  
pp. 131253 ◽  
Author(s):  
Young-Ho Seo ◽  
Ji-Woo Park ◽  
Woo-Jin Song ◽  
Beom-Soo Kang ◽  
Jeong Kim
Keyword(s):  
Closed Loop ◽  
Three Dimensional ◽  
Loop System ◽  
Die Design ◽  
Manufacturing Cost ◽  
Closed Loop System ◽  
Forming Process ◽  
Element Analysis ◽  
Springback Compensation ◽  
Flexible Die

Springback in metal forming process often results in undesirable shape changes in formed parts and leads to deterioration in product quality. Even though springback can be predicted and compensated for through the theories or methodologies established thus far, an increase in manufacturing cost accompanied by a change in die shape is inevitable. In the present paper, it is suggested that the cost accompanied with springback compensation can be minimized while allowing the processing of various three-dimensional curved surfaces by using a flexible die composed of multiple punches. With the die being very flexible, the iterative trial-and-error method can be readily applied to compensate for the springback. Thus, repeated designing and redesigning of solid or matched dies can be avoided, effectively saving considerable time. Only some adjustments of punch height are required. Detailed designs of the flexible die as well as two core algorithms to control the respective punch heights are described in this paper. In addition, a closed-loop system for the springback compensation using the flexible die is proposed. The amount of springback was simulated by a finite element analysis and the modified displacement adjustment (DA) method as the springback compensation model was used in the closed-loop system. This system was applied to a two-dimensional quadratic shape problem, and its robustness was verified by an experiment.

The Strain Analysis at the Broadening Stage of the Hollow Railway Axle by Multi-Wedge Cross Wedge Rolling

2014 ◽  
Vol 494-495 ◽  
pp. 457-460 ◽  
Author(s):  
Bin Hu ◽  
Xue Dao Shu ◽  
Peng Hui Yu ◽  
Wen Fei Peng
Keyword(s):  
Production Efficiency ◽  
Strain Analysis ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Element Analysis ◽  
Forming Mechanism ◽  
Railway Axle ◽  
The Finite Element Analysis ◽  
Scientific Significance ◽  
Deform 3D

The paper is based on the newest hollow railway axle, which utilizes the Pro/E designed multi-wedge cross wedge rolling (MCWR) model, utilizes the finite element analysis software DEFORM-3D to complete the numerical simulation about the whole stage of the hollow railway axle forming process, and analyzes the strain rule at the broadening stage of the hollow railway axle, especially conducts a detailed research on forming character into the strain rule at the multi-wedge transition stage, and finally gets the strain forming mechanism of the hollow railway axle at the broadening stage. The result of the research on the strain rule poses great scientific significance on enhancing the product quality and the production efficiency of the hollow railway axle, and improving the theory of multi-wedge cross wedge rolling.

Optimization of Sheet Metal Process Parameters of a Shield Case Piece Using Computer Simulation

2006 ◽  
Vol 510-511 ◽  
pp. 330-333
Author(s):  
M.C. Curiel ◽  
Ho Sung Aum ◽  
Joaquín Lira-Olivares
Keyword(s):  
Sheet Metal ◽  
Thickness Distribution ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Physical Processes ◽  
Forming Process ◽  
Element Analysis ◽  
One Step ◽  
Range Of Values ◽  
Principal Strains

Numerical simulations based on Finite Element Analysis (FEA) are widely used to predict and evaluate the forming parameters before performing the physical processes. In the sheet metal industry, there are basically two types of FE programs: the inverse (one-step) programs and the incremental programs. In the present paper, the forming process of the shield case piece (LTA260W1-L05) was optimized by performing simulations with both types of software. The main analyzed parameter was the blankholding force while the rest of the parameters were kept constant. The criteria used to determine the optimum value was based on the Forming Limit Diagram (FLD), fracture and wrinkling of the material, thickness distribution, and the principal strains obtained. It was found that the holding force during the forming process deeply affects the results, and a range of values was established in which the process is assumed to give a good quality piece.

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