scholarly journals Experimental and Computational analysis of springback in dual phase steels

2021 ◽  
Vol 26 (2) ◽  
pp. 137-145
Author(s):  
Rodolfo Rodríguez Baracaldo ◽  
Yeison Parra-Rodríguez ◽  
José Manuel Arroyo-Osorio
Keyword(s):  
Elastic Recovery ◽  
Plastic Anisotropy ◽  
Microstructural Analysis ◽  
Rolling Direction ◽  
Experimental Tests ◽  
Tensile Tests ◽  
Bending Test ◽  
Uniaxial Tensile ◽  
Dual Phase ◽  
Characteristic Region

In this work the comfortability of dual-phase automotive steel DP600 is studied through uniaxial tensile tests and V-die bending tests in different directions relative to the rolling direction. A microstructural analysis was also carried out in each characteristic region of the deformation zone, evidencing the changes in the morphology of the microstructure grains. Additionally, the plastic anisotropy of the material was studied by implementing the constitutive anisotropy models known as Hill-48 and Barlat-89. The results showed an increase in elastic recovery at 45 ° and 90 ° from the rolling direction. This variation can be attributed to the morphology of the martensite that created preferential location zones within the material during the rolling process. The two models Hill-48 and Barlat-89 correctly describe the yield surface and the plastic anisotropy obtained in the experimental tests carried out. The simulation using the finite element method and the Hill-48 model gave satisfactory results in the prediction of the elastic recovery as compared to the experimental results obtained with the V-die bending test.

Experimental Analysis of Forming Limits and Thickness Strains of DP600-800 Steels

2016 ◽  
Vol 835 ◽  
pp. 230-235 ◽  
Author(s):  
Marcelo Costa Cardoso ◽  
Alexandre de Melo Pereira ◽  
Fabiane Roberta Freitas da Silva ◽  
Luciano Pessanha Moreira
Keyword(s):  
Shear Failure ◽  
Plastic Anisotropy ◽  
Rolling Direction ◽  
Tensile Tests ◽  
Plastic Instability ◽  
Tensile Fracture ◽  
Forming Limit ◽  
Uniaxial Tensile ◽  
Plastic Behavior ◽  
Fractured Surface

In this work, the plastic behavior of cold-rolled zinc coated dual-phase steel sheets DP600 and DP800 grades is firstly investigated by means of uniaxial tensile and Forming Limit Curve (FLC) testing. The uniaxial tensile tests were carried out at 0o, 45o and 90o angular orientations with respect to the rolling direction to evaluate the mechanical properties and the plastic anisotropy Lankford r-values. The forming limit strains are defined according to Nakajima’s procedure. Thickness measurements of tested Nakajima’s samples cut perpendicular to the fracture allowed to identify a rapid decrease of the strain, which governs the plastic instability that preceded the fracture in the drawing region of the FLC. Optical metallographic and scanning electron microscopy techniques helped to characterize and distinguish the orientation of rotated grains and flat fractured surface (ductile shear failure in blank specimens close to plane-strain tension) from no grain rotations and rough fractured surface (ductile tensile fracture in blank geometries in the biaxial stretching domain).

Influence of Continuous Annealing Conditions on the Microstructure and Mechanical Properties of a C-Mn Dual Phase Steel

2010 ◽  
Vol 638-642 ◽  
pp. 3479-3484 ◽  
Author(s):  
Roberta O. Rocha ◽  
Tulio M.F. Melo ◽  
Dagoberto Brandao Santos
Keyword(s):  
Mechanical Properties ◽  
Microstructural Analysis ◽  
Tensile Tests ◽  
Recrystallization Temperature ◽  
Continuous Annealing ◽  
Dual Phase ◽  
Heating Rates ◽  
Microstructure And Mechanical Properties ◽  
Annealing Cycle ◽  
Soaking Temperature

The influence of continuous annealing variables on the microstructure and mechanical properties of a C-Mn Dual Phase (DP) steel was studied. The annealing cycles were simulated using a Gleeble machine. Some specimens were quenched at different stages of the annealing cycle in order to evaluate the microstructural evolution during the annealing process. Tensile tests and microstrutural analysis were carried out. The results showed that high heating rates increased the final recrystallization temperature and as a consequence the microstructure obtained was refined. Austenite grain nucleation and growth were also influenced by the heating rates. Soaking temperature was the most influent variable on the mechanical properties, i. e., the yield strength increased and the tensile strength decreased with an increase in the soaking temperature. Microstructural analysis showed that not only martensite, but also bainite and martensite-retained autenite constituent (MA) were formed. Undissolved carbides were also detected by transmission electron microscopy.

scholarly journals Influence of the Texture on the Al–6%Mg Alloy Deformation

1999 ◽  
Vol 33 (1-4) ◽  
pp. 111-123
Author(s):  
T. A. Lychagina ◽  
D. I. Nikolayev
Keyword(s):  
Materials Science ◽  
Tensile Axis ◽  
Deformation Behaviour ◽  
Rolling Direction ◽  
Tensile Tests ◽  
Orientation Distribution ◽  
Alloy Sheet ◽  
Mg Alloy ◽  
Uniaxial Tensile ◽  
Mathematical Methods

The influence of the texture on material mechanical properties and deformation behaviour was widely discussed. (refer to Bunge, H.J. (1982). Texture Analysis in Materials Science Mathematical Methods). Butterworths, London. In this work elastic properties (Young's modulus) of cold rolled Al–6%Mg alloy sheet were estimated taking into account lattice preferred orientations, which can be described by the orientation distribution function (ODF). The ODF was reconstructed from pole figures measured by means of neutron diffraction and was approximated by normal distributions (Savyolova, T.I. (1994)Zavodskaya Laboratoria 50, N5, 48–52). The method used for calculation is able to express explicitly the polycrystalline elastic property via the single crystal property and the texture parameters.Stress–strain dependenc (deformation curves) was measured by means of uniaxial tensile tests for Al–6%Mg alloy samples with different tensile axis directions. Samples for uniaxial tests were cut at different angles to the rolling direction. The conformity between experimental and computed results is discussed.

scholarly journals Investigation on the ductile fracture of a high-strength dual-phase steel with anisotropic damage mechanics model

2021 ◽  
Author(s):  
Zinan Li ◽  
Wenqi Liu ◽  
Fuhui Shen ◽  
Sebastian Münstermann ◽  
Junhe Lian
Keyword(s):  
Plastic Deformation ◽  
Ductile Fracture ◽  
Fracture Behavior ◽  
Dual Phase Steel ◽  
High Strength ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Dual Phase ◽  
Plasticity Model ◽  
Anisotropic Plastic

In this study, a hybrid experimental and numerical investigation is implemented to characterize the plasticity and ductile fracture behavior of a high-strength dual-phase steel. Uniaxial tensile tests are conducted along the three typical directions of rolled sheet metals for the anisotropic plastic behavior, while the hydraulic bulge test is applied for the flow behavior under equiaxial biaxial tension. Further tensile tests are conducted on various featured dog-bone specimens to study the fracture behavior of the material from the uniaxial to plane-strain tension. On the numerical side, the evolving non-associated Hill48 (enHill48) plasticity model considering anisotropic hardening and plastic strain ratio evolution is employed to describe the anisotropic plastic deformation. The extended enHill48 model with damage and fracture formulation is further calibrated and validated in the study to describe the ductile fracture behavior of the steel under various stress states. Through a comparison of the results based on the evolving anisotropic model with the isotropic Mises model, it is concluded that even for materials that show only minor initial plastic anisotropy, it could develop a non-negligible influence on the large plastic deformation and the prediction of both deformation and fracture shows profound improvement with the evolving anisotropic plasticity model.

Effect of specimen orientation to the rolling direction on uniaxial tensile forming and failure limits

2020 ◽  
Vol 234 (13) ◽  
pp. 1598-1603
Author(s):  
Puja Ghosal ◽  
Surajit Kumar Paul
Keyword(s):  
Sheet Metal ◽  
Ferritic Steel ◽  
Dual Phase Steel ◽  
Rolling Direction ◽  
Image Correlation ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Correlation Technique ◽  
Dual Phase ◽  
Planar Anisotropy

Alteration of forming and failure limits due to planar anisotropy of the sheet metal significantly affects the safe forming operation region and finally successfully manufacturing of a sheet metal formed component. This article presents the effect of planar anisotropy on uniaxial tensile properties, forming and failure limits of cold-rolled ferritic and dual-phase steels. In-situ three dimensional digital image correlation technique is used to measure the evolution of local strain components during uniaxial tensile test. For both the steels, necking limit is highest for the specimen at an orientation of 90° to rolling direction, while failure limit is highest for those specimen whose orientation is 45° to rolling direction for ferritic steel, and both 0° and 90° to rolling direction for dual-phase steel. Uniaxial tensile deformation path for ferritic steel holds lower slope than dual-phase steel as depicted in major versus minor strain plot.

scholarly journals Improving Prediction of Springback in Sheet Metal Forming Using Multilayer Perceptron-Based Genetic Algorithm

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3129
Author(s):  
Tomasz Trzepieciński ◽  
Hirpa G. Lemu
Keyword(s):  
Genetic Algorithm ◽  
Multilayer Perceptron ◽  
Sheet Material ◽  
Rolling Direction ◽  
Back Propagation ◽  
Bending Test ◽  
Uniaxial Tensile ◽  
Multilayer Perceptrons ◽  
Input Parameters ◽  
Springback Coefficient

This paper presents the results of predictions of springback of cold-rolled anisotropic steel sheets using an approach based on a multilayer perceptron-based artificial neural network (ANN) coupled with a genetic algorithm (GA). A GA was used to optimise the number of input parameters of the multilayer perceptron that was trained using different algorithms. In the investigations, the mechanical parameters of sheet material determined in uniaxial tensile tests were used as input parameters to train the ANN. The springback coefficient, determined experimentally in the V-die air bending test, was used as an output variable. It was found that specimens cut along the rolling direction exhibit higher values of springback coefficient than specimens cut transverse to the rolling direction. An increase in the bending angle leads to an increase in the springback coefficient. A GA-based analysis has shown that Young’s modulus and ultimate tensile stress are variables having no significant effect on the coefficient of springback. Multilayer perceptrons trained by back propagation, conjugate gradients and Lavenberg–Marquardt algorithms definitely favour punch bend depth under load as the most important variables affecting the springback coefficient.

In-situ EBSD study of deformation behaviour of 600 MPa grade dual phase steel during uniaxial tensile tests

2019 ◽  
Vol 759 ◽  
pp. 624-632 ◽  
Author(s):  
Shengci Li ◽  
Chengyu Guo ◽  
Leilei Hao ◽  
Yonglin Kang ◽  
Yuguo An
Keyword(s):  
Dual Phase Steel ◽  
Deformation Behaviour ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Dual Phase

On the Investigation of the Portevin-Le Chatelier Effect in the Rolling of AA 5083

2016 ◽  
Vol 710 ◽  
pp. 175-180
Author(s):  
Antonello Astarita ◽  
Mariacira Liberini ◽  
Carla Velotti ◽  
Ciro Sinagra ◽  
Antonino Squillace
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Microstructural Analysis ◽  
Rolling Direction ◽  
Tensile Tests ◽  
Rolling Process ◽  
Final Heat Treatment ◽  
Experimental Campaign ◽  
Chatelier Effect ◽  
The One

The aim of this paper is to investigate about the Portevin-Le Chatelier Effect (PLC) on a AA 5083 sheet. In order to study the minimizing of the PLC effect, three different rolling cyles have been carried out and an experimental campaign on the three different AA 5083 rolled has been carried out. In particular, the experimental campaign, to better understand the evolution of the phenomena during the rolling process, is based on: microstructural analysis, tensile tests and fractographic observations. Finally it has been found that the greater grain size the smaller the PLC effect, even if this effect cannot be totally removed, furthermore the PLC effect occurs only in the rolling direction. The best rolling cycle is the one that provide a hot rolling until 4mm, then a cold rolling up to 2mm and a final heat treatment of annealing.

Numerical Investigation for Evaluation and Prevention of Casting Defects in TiAl Alloys

2014 ◽  
Vol 611-612 ◽  
pp. 1807-1814 ◽  
Author(s):  
Ildiko Peter ◽  
Mario Rosso ◽  
Ilaria Forno
Keyword(s):  
Microstructural Analysis ◽  
Charpy Impact ◽  
Experimental Tests ◽  
Tensile Tests ◽  
Efficient Production ◽  
Casting Defects ◽  
Simulation Tools ◽  
Development Costs ◽  
Two Samples ◽  
Alloy Properties

Simulation tools have been effectively employed in many applications for numerically investigate on the development of efficient production processes aiming to materials quality enhancement. Such studies allow drastically reduction of the number of experimental tests and consequently of the development costs and further of the time-to-market. In this framework, the present paper focuses on the study of filling rate and of the solidification times of Titanium alloys. Starting from some acquired experimental data, considering appropriate boundary conditions and properly setting of the external parameters (flow-rate, liquid temperature, etc.), the study targets optimizing the processing cycle and reducing the presence of defects in casting. The cast tree used for the research is a symmetric one, including two samples used for Charpy impact tests and two samples for tensile tests. The considered commercial software provides a complete finite element solution and has been employed facilitating to prevent casting defects. During the simulations, the process parameters and the alloy properties have been explicitly taken into account. Information about how the parameters should be modified to achieve the optimal conditions close to a defects-free castings was achieved. A good correlation, in terms of microstructural analysis, between the simulation data and the experimentally obtained results was obtained, confirming the reliability of the model.

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