scholarly journals Springback Compensation in Cold Forming Process for High Strength Steel / Kompensacja sprężynowania w procesie formowania stali na zimno

2015 ◽  
Vol 60 (4) ◽  
pp. 2471-2478 ◽  
Author(s):  
P. Bałon ◽  
A. Świątoniowski

Process of metal forming in automotive parts construction becomes more and more demanding due to tightened up tolerance and trials to realize very complex and in many cases unworkable design in mass production. Moreover it is required to cut and limit costs of die production and simultaneously keep high quality. Furthermore, construction elements are more often produced from materials which belong to High Strength Steel or Ultra High Strength Steel. Application of this kind of materials considerably reduces construction mass due to high durability. Nevertheless, it results in appearance of springback effect. Springback value depends mainly on used material as well as part geometry and in extreme cases deviation value from target part might reach in some areas high level. Reduction of implementation time, development of metal components and greater restrictions about designing and producing stamping tools generate extra costs. Designing of dies requires using of appropriate Finite Element Method software to make them more economic and less time-consuming. Therefore analysis of forming process alone is not enough to be taken into account. During the design process it is needed to include the die compensation to reach optimized blank sheet. Prediction of springback effect by tryout method and then correction of deviation is difficult arduous and painstaking. Virtual compensation methods make it possible to receive precise result in a short time. This way gives a huge economic advantage eliminating useless milling and allows to produce of die just in time. Optimization process can relate to individual operation as well as take into consideration intermediate stages in the final result, at the same time increasing the accuracy. Die compensation with software application was experimentally verified by prototype die. Quality requirements regarding products of sheet stamping process are very high due to the technologies of automatic assembly of formed components. Springback, as the main source of drawpieces inaccuracy, is the function of material data, shape of tools and process parameters. Therefore, springback deformation becomes critical problem especially for AHSS steel when the geometry is complex. Hence, it is necessary not only to find springback effect value but also include it during early stage of designing by tooling designers.

2020 ◽  
Vol 13 (3) ◽  
pp. 409-421 ◽  
Author(s):  
S. Gothivarekar ◽  
S. Coppieters ◽  
A. Van de Velde ◽  
D. Debruyne

2016 ◽  
Vol 693 ◽  
pp. 800-806
Author(s):  
You Dan Guo

In high-strength steel hot forming, under the heating and quenching interaction, the material is oxidized and de-carbonized in the surface layer, forming a gradual change microstructure composed of ferrite, ferrite and martensite mixture and full martensite layers from surface to interior. The experiment enunciation: Form the table to ferrite, ferrite and martensite hybrid organization, completely martensite gradual change microstructure,and make the strength and rigidity of material one by one in order lower from inside to surface, ductility one by one in order increment in 22MnB5 for hot forming;Changes depends on the hot forming process temperature and the control of reheating furnace gas content protection, when oxygen levels of 5% protective gas, can better prevent oxidation and decarburization;Boron segregation in the grain boundary, solid solution strengthening, is a major cause of strength increase in ;The gradual change microstructure in outer big elongation properties, make the structure of the peak force is relatively flat, to reduce the peak impact force of structure, keep the structure of high energy absorption capacity;With lower temperature, the material yield strength rise rapidly,when the temperature is 650 °C, the yield strength at 950 °C was more than 3 times as much.


2014 ◽  
Vol 622-623 ◽  
pp. 201-206 ◽  
Author(s):  
Kenichiro Mori ◽  
Tomoyoshi Maeno ◽  
Shohei Nakamoto

A hot spline forming process of die-quenched gear drums using resistance heating of a side wall of a cup formed by cold deep drawing and ironing was developed. The side wall having uniform cross-sectional area is resistance-heated by passage of the current in the axial direction, the heated side wall of the drawn cup is ironed and is finally die-quenched. The gear drum was successfully formed and the hardness was between 400 and 500 HV. Not only the formability was improved but also the formed dram was hardly oxidised because of rapid resistance heating.


Author(s):  
Irina GRIGORE ◽  
Severin CAZANESCU ◽  
Raluca Alexandra CAZANESCU

In our days, communities have to face high level of water and food consumption based on uncertain supplies and growing demands. Thus, they work to prevent floods, soil erosion, to supply fresh water for population, industry and irrigation and to redirect streams and rivers in order to increase the food production. On the other hand, climate changes increased the frequency of extreme events like droughts and floods, and water management became a matter of great concern, in order to protect and preserve fertile land and drinkable water resources. Powerful software are needed to help environmental specialists to develop reliable projects for sustainable land development, in a short time. In the present paper, we will briefly present AutoCAD Civil 3D 2010, the most powerful software application released by Autodesk Inc., a short time ago. Using AutoCAD Civil 3D 2010 components together with new set of extensions, named Hydraflow Extension, land development specialists can deal with a large variety of hydrologic and hydraulic aspects, such as delineating watersheds and drainage areas and computing time of concentration and other rainfall-runoff relationship for the designated basins.


2021 ◽  
Author(s):  
Huajie Mao ◽  
Han Chen ◽  
Yanxiong Liu ◽  
Kaisheng Ji

Abstract Fine blanking is a kind of metal forming process with the advantages of high precision, good surface quality and low cost. Influenced by the concept of lightweight, a large number of metal materials with high strength are widely used in various fields. High strength materials are prone to be cracked during plastic deformation due to their poor plasticity, which limits the application range of them. This paper proposed a force variation fine blanking process for high-strength and low-plasticity materials. At the same time, a method to find the curve of forming force for this novel process was presented. A 2D finite element fine blanking model was established for the TC4 material. Combining genetic algorithm and neural network methods, a model was built up to find the optimal forming force loading curve. The parts fabricated by force variation loading and constant loading fine blanking process were compared through experiments. The mechanism of force variation fine blanking is also revealed. The forming force mainly affects the length of clean cutting surface by affecting hydrostatic stress. According to the ultimate optimal loading curve, the forming force should be kept at a low level in the early stage of blanking stroke, and increased gradually in the ending stage. In the application of force variation fine blanking, the part with long length of clean cutting surface can be obtained with lower die load.


2018 ◽  
Vol 878 ◽  
pp. 296-301
Author(s):  
Dong Won Jung

The roll forming is one of the simplest manufacturing processes for meeting the continued needs of various industries. The roll forming is increasingly used in the automotive industry to form High Strength Steel (HSS) and Advanced High Strength Steel (AHSS) for making structural components. In order to reduce the thinning of the sheet product, traditionally the roll forming has been suggested instead of the stamping process. The increased product performance, higher quality, and the lowest cost with other advantages have made roll forming processes suitable to form any shapes in the sheets. In this numerical study, a Finite Element Method is applied to estimate the stress, strain and the thickness distribution in the metal sheet with quadrilateral shape, ribs formed by the 11 steps roll forming processes using a validated model. The metal sheet of size 1,000 × 662 × 1.6 mm taken from SGHS steel was used to form the quadrilateral shape ribs on it by the roll forming process. The simulation results of the 11 step roll forming show that the stress distribution was almost uniform and the strain distribution was concentrated on the ribs. The maximum thinning strain was observed in the order of 15.5 % in the middle rib region possibly due to the least degree of freedom of the material.


2010 ◽  
Vol 97-101 ◽  
pp. 420-425
Author(s):  
Wei Chen ◽  
S. Cheng ◽  
Y. Ding ◽  
Y.Q. Guo ◽  
L. Xue

The method for establishing the forming limit diagram (FLD) of multi-gauge high strength steel laser tailor-welded blanks (LTWB) is introduced based on analyzing the failure mechanism of multi-gauge LTWB. The Nakazima test is performed to generate the limit strain of multi-gauge high strength steel LTWB. By means of the ARGUS strain measuring system, the limit strain is measured and the FLD of LTWB is plotted subsequently. The FLD established by the Nakazima test is introduced into the FEA forming process as the failure criteria. Compared with the predicted result of the FLD of thinner metal, better correlation between the simulation and experimental results is indicated by adopting the FLD of LTWB as the necking criteria, which also reveals the validity and practicability of the FLD research method for multi-gauge high strength steel LTWB.


2010 ◽  
Vol 154-155 ◽  
pp. 1223-1227 ◽  
Author(s):  
Zhi Guo An ◽  
Yu Zhang

In sheet metal forming process, the input process parameters scatter and considerably result in unreliablity in practical production. Optimization for sheet metal forming process is often considered as a multi-objective problem. An optimizition strategy for high strength steel (HSS) sheet metal forming process was suggested based on response surface methodology (RSM). Latin Hypercube Sampling (LHS) method was introduced to design the rational experimental samples; the objective function was defined based on cracking factor wrinkle factor and severe thinning factor; the accurate response surface for sheet metal forming problem was built by Least Square Method; Multi-objective Genetic Algorithm(MOGA) was adoped in optimization and Pareto solution was selected. The strategy was applied to analyze a HSS auto-part, the result has proved this method suitable for optimization design of HSS sheet metal forming process.


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