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Draxler, J., Åkerström, P., Edberg, J., Lindgren, L.-E., Singh, S., Raza, T. & Andersson, J. (2020). A numerical model for simulating the effect of strain rate on eutectic band thickness. Welding in the World, 64(10), 1635-1658
Open this publication in new window or tab >>A numerical model for simulating the effect of strain rate on eutectic band thickness
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2020 (English)In: Welding in the World, ISSN 0043-2288, E-ISSN 1878-6669, Vol. 64, no 10, p. 1635-1658Article in journal (Refereed) Published
Abstract [en]

Large tensile strains acting on the solidifying weld metal can cause the formation of eutectic bands along grain boundaries. These eutectic bands can lead to severe liquation in the partially melted zone of a subsequent overlapping weld. This can increase the risk of heat-affected zone liquation cracking. In this paper, we present a solidification model for modeling eutectic bands. The model is based on solute convection in grain boundary liquid films induced by tensile strains. The proposed model was used to study the influence of strain rate on the thickness of eutectic bands in Alloy 718. It was found that when the magnitude of the strain rate is 10 times larger than that of the solidification rate, the calculated eutectic band thickness is about 200 to 500% larger (depending on the solidification rate) as compared to when the strain rate is zero. In the paper, we also discuss how eutectic bands may form from hot cracks.

Place, publisher, year, edition, pages
Springer, 2020
Keywords
Macrosegregation, Solidification, Hot cracking, Alloy 718
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-76423 (URN)10.1007/s40194-020-00918-y (DOI)000540687300001 ()2-s2.0-85086930636 (Scopus ID)
Note

Validerad;2020;Nivå 2;2020-09-21 (johcin)

Available from: 2019-10-17 Created: 2019-10-17 Last updated: 2023-09-05Bibliographically approved
Olaogun, O., Edberg, J., Lindgren, L.-E., Oluwole, O. O. & Akinlabi, E. (2019). Heat transfer in cold rolling process of AA8015 alloy: a case study of 2-D FE simulation of coupled thermo-mechanical modeling. The International Journal of Advanced Manufacturing Technology, 100(9-12), 2617-2627
Open this publication in new window or tab >>Heat transfer in cold rolling process of AA8015 alloy: a case study of 2-D FE simulation of coupled thermo-mechanical modeling
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2019 (English)In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 100, no 9-12, p. 2617-2627Article in journal (Refereed) Published
Abstract [en]

The finite element method (FEM) is one of the most applicable mathematical analytic methods of rolling processes and is also an efficient method for analyzing coupled heat transfer. Thermal analysis of cold rolling process is not frequently used due to the widespread assumption of insignificant impact during rolling process. This research focuses on the development of coupled thermo-mechanical 2-D FE model analysis approach to study the thermal influence and varying coefficient of friction during the industrial cold rolling process of AA8015 aluminum alloy. Both deformable-rigid and deformable-deformable rigid contact algorithms were examined in the 2-D FE model. Findings revealed that temperature distribution in the roll bite rises steadily in a stepwise manner. The deformable-deformable contact algorithm is the best investigations of thermal behavior of the rolled metal and work rolls necessary for typical application in work roll design. The predicted roll separating force is validated with industrial measurements.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
2-D FE model, Contact algorithm, Coupled thermo-mechanical, Heat transfer
National Category
Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-71692 (URN)10.1007/s00170-018-2811-2 (DOI)000458310400033 ()2-s2.0-85055479036 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-03-08 (johcin)

Available from: 2018-11-21 Created: 2018-11-21 Last updated: 2019-03-08Bibliographically approved
Draxler, J., Edberg, J., Andersson, J. & Lindgren, L.-E. (2019). Modeling and simulation of weld solidification cracking part I: A pore-based crack criterion. Welding in the World, 63(5), 1489-1502
Open this publication in new window or tab >>Modeling and simulation of weld solidification cracking part I: A pore-based crack criterion
2019 (English)In: Welding in the World, ISSN 0043-2288, E-ISSN 1878-6669, Vol. 63, no 5, p. 1489-1502Article in journal (Refereed) Published
Abstract [en]

Several advanced alloy systems are susceptible to weld solidification cracking. One example is nickel-based superalloys, which are commonly used in critical applications such as aerospace engines and nuclear power plants. Weld solidification cracking is often expensive to repair and, if not repaired, can lead to catastrophic failure. This study, presented in three papers, presents an approach for simulating weld solidification cracking applicable to large-scale components. The results from finite element simulation of welding are post-processed and combined with models of metallurgy, as well as the behavior of the liquid film between the grain boundaries, in order to estimate the risk of crack initiation. The first paper in this study describes the crack criterion for crack initiation in a grain boundary liquid film. The second paper describes the model for computing the pressure and the thickness of the grain boundary liquid film, which are required to evaluate the crack criterion in paper 1. The third and final paper describes the application of the model to Varestraint tests of alloy 718. The derived model can fairly well predict crack locations, crack orientations, and crack widths for the Varestraint tests. The importance of liquid permeability and strain localization for the predicted crack susceptibility in Varestraint tests is shown.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Solidification cracking, Hot cracking, Varestraint testing, Computational welding mechanics, Alloy 718
National Category
Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-75660 (URN)10.1007/s40194-019-00760-x (DOI)000482459300029 ()2-s2.0-85068801005 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-08-22 (johcin)

Available from: 2019-08-22 Created: 2019-08-22 Last updated: 2023-09-05Bibliographically approved
Draxler, J., Edberg, J., Andersson, J. & Lindgren, L.-E. (2019). Modeling and simulation of weld solidification cracking part II: A model for estimation of grain boundary liquid pressure in a columnar dendritic microstructure. Welding in the World, 63(5), 1503-1519
Open this publication in new window or tab >>Modeling and simulation of weld solidification cracking part II: A model for estimation of grain boundary liquid pressure in a columnar dendritic microstructure
2019 (English)In: Welding in the World, ISSN 0043-2288, E-ISSN 1878-6669, Vol. 63, no 5, p. 1503-1519Article in journal (Refereed) Published
Abstract [en]

Several advanced alloy systems are susceptible to weld solidification cracking. One example is nickel-based superalloys, which are commonly used in critical applications such as aerospace engines and nuclear power plants. Weld solidification cracking is often expensive to repair, and if not repaired, can lead to catastrophic failure. This study, presented in three papers, presents an approach for simulating weld solidification cracking applicable to large-scale components. The results from finite element simulation of welding are post-processed and combined with models of metallurgy, as well as the behavior of the liquid film between the grain boundaries, in order to estimate the risk of crack initiation. The first paper in this study describes the crack criterion for crack initiation in a grain boundary liquid film. The second paper describes the model for computing the pressure and the thickness of the grain boundary liquid film, which are required to evaluate the crack criterion in paper 1. The third and final paper describes the application of the model to Varestraint tests of Alloy 718. The derived model can fairly well predict crack locations, crack orientations, and crack widths for the Varestraint tests. The importance of liquid permeability and strain localization for the predicted crack susceptibility in Varestraint tests is shown.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Solidification cracking, Hot cracking, Varestraint testing, Computational welding mechanics, Alloy 718
National Category
Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-75653 (URN)10.1007/s40194-019-00761-w (DOI)000482459300030 ()2-s2.0-85068150806 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-08-22 (johcin)

Available from: 2019-08-22 Created: 2019-08-22 Last updated: 2023-09-05Bibliographically approved
Draxler, J., Edberg, J., Andersson, J. & Lindgren, L.-E. (2019). Modeling and simulation of weld solidification cracking part III: Simulation of solidification cracking in Varestraint tests of alloy 718. Welding in the World, 63(6), 1883-1901
Open this publication in new window or tab >>Modeling and simulation of weld solidification cracking part III: Simulation of solidification cracking in Varestraint tests of alloy 718
2019 (English)In: Welding in the World, ISSN 0043-2288, E-ISSN 1878-6669, Vol. 63, no 6, p. 1883-1901Article in journal (Refereed) Published
Abstract [en]

Several advanced alloy systems are susceptible to weld solidification cracking. One example is nickel-based superalloys, which are commonly used in critical applications such as aerospace engines and nuclear power plants. Weld solidification cracking is often expensive to repair, and if not repaired, can lead to catastrophic failure. This study, presented in three papers, presents an approach for simulating weld solidification cracking applicable to large-scale components. The results from finite element simulation of welding are post-processed and combined with models of metallurgy, as well as the behavior of the liquid film between the grain boundaries, in order to estimate the risk of crack initiation. The first paper in this study describes the crack criterion for crack initiation in a grain boundary liquid film. The second paper describes the model required to compute the pressure and thickness of the liquid film required in the crack criterion. The third and final paper describes the application of the model to Varestraint tests of alloy 718. The derived model can fairly well predict crack locations, crack orientations, and crack widths for the Varestraint tests. The importance of liquid permeability and strain localization for the predicted crack susceptibility in Varestraint tests is shown.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Solidification cracking, Hot cracking, Varestraint testing, Computational welding mechanics, Alloy 718
National Category
Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-76421 (URN)10.1007/s40194-019-00784-3 (DOI)000501904600030 ()2-s2.0-85071447851 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-12-06 (johcin)

Available from: 2019-10-17 Created: 2019-10-17 Last updated: 2023-09-05Bibliographically approved
Lindgren, L.-E., Edberg, J., Åkerström, P. & Zhang, Z. (2019). Modeling of thermal stresses in low alloy steels. Paper presented at The 12th International Congress on Thermal Stresses June 1–5, 2019, Zhejiang University, Hangzhou, China. Journal of thermal stresses, 42(6), 725-743
Open this publication in new window or tab >>Modeling of thermal stresses in low alloy steels
2019 (English)In: Journal of thermal stresses, ISSN 0149-5739, E-ISSN 1521-074X, Vol. 42, no 6, p. 725-743Article in journal (Refereed) Published
Abstract [en]

Computing the evolution of thermal stresses accurately requires appropriate constitutive relations. This includes both the thermal and mechanical aspects, as temperature is the driver to thermal stresses. The paradigm of Integrated Computational Materials Engineering (ICME) aims at being able to quantitatively relate process-structure-property of a material. The article describes physics based models, denoted bridging elements, which are one step towards the vision of ICME. They couple material structure with heat capacity, heat conductivity, thermal and transformation strains and elastic properties for hypo-eutectoid steels. The models can account for the chemical composition of the steel and its processing, i.e. thermomechanical history, giving the evolution of the microstructure and the corresponding properties.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Elastic properties, heat capacity, heat conductivity, thermal expansion, thermal stresses
National Category
Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-73488 (URN)10.1080/01495739.2019.1587329 (DOI)000468282400003 ()2-s2.0-85063905757 (Scopus ID)
Conference
The 12th International Congress on Thermal Stresses June 1–5, 2019, Zhejiang University, Hangzhou, China
Note

Konferensartikel i tidskrift

Available from: 2019-04-08 Created: 2019-04-08 Last updated: 2020-08-24Bibliographically approved
Draxler, J., Edberg, J., Andersson, J. & Lindgren, L.-E. (2019). Simulation of weld solidifiation cracking in varestraint tests of alloy 718. In: C. Sommitsch, N. Enzinger, P. Mayr (Ed.), Mathematical Modelling of Weld Phenomena 12: Selected peer reviewed papers from the 12th International Seminar Numerical Analysis of Weldability. Paper presented at 12th International Seminar 'Numerical Analysis of Weldability', 23-26 September, 2018, Graz, Austria (pp. 485-504). Gratz
Open this publication in new window or tab >>Simulation of weld solidifiation cracking in varestraint tests of alloy 718
2019 (English)In: Mathematical Modelling of Weld Phenomena 12: Selected peer reviewed papers from the 12th International Seminar Numerical Analysis of Weldability / [ed] C. Sommitsch, N. Enzinger, P. Mayr, Gratz, 2019, p. 485-504Conference paper, Published paper (Refereed)
Abstract [en]

Several nickel-based superalloys are susceptible to weld solidification cracking. Numerical simulation can be a powerful tool for optimizing the welding process such that solidification cracking can be avoided. In order to simulate the cracking, a crack model inspired by the RDG model is proposed. The model is based on a crack criterion that estimates the likelihood for a preexisting pore in a grain boundary liquid film to form a crack. The criterion depends on the thickness and the liquid pressure in the grain boundary liquid film, as well as the surface tension of the pore. The thickness of the liquid film is computed from the macroscopic mechanical strain field of an FE model with a double ellipsoidal heat source. A temperature-dependent length scale is used to partition the macroscopic strain to the liquid film. The liquid pressure in the film is evaluated using a combination of Poiseuille parallel plate flow and Darcy’s law for porous flows. The Poiseuille flow is used for the part of the grain boundary liquid film that extends into the region with liquid fraction less than 0.1, while Darcy’s law is used for the rest of the liquid film that extends into the regions with liquid fraction greater than 0.1. The proposed model was calibrated and evaluated in Varestraint tests of Alloy 718. Crack location, width, and orientation were all accurately predicted by the model.

Place, publisher, year, edition, pages
Gratz: , 2019
Series
Mathematical Modelling of Weld Phenomena, ISSN 2410-0544 ; 12
Keywords
Solidification cracking, Hot cracking, Varestraint testing, Computational Welding Mechanics, Alloy 718
National Category
Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-75740 (URN)10.3217/978-3-85125-615-4-26 (DOI)
Conference
12th International Seminar 'Numerical Analysis of Weldability', 23-26 September, 2018, Graz, Austria
Note

ISBN för värdpublikation: 978-3-85125-615-4, 978-3-85125-616-1

Available from: 2019-08-29 Created: 2019-08-29 Last updated: 2023-09-05Bibliographically approved
Edberg, J., Draxler, J. & Andersson, J. (2018). Comparison of two different indicators for hot cracking in welded structures. In: ICAS 2018: 31st Congress of the International Council of Aeronautical Sciences. Paper presented at 31st Congress of the International Council of the Aeronautical Sciences (ICAS 2018), 9-14 September, 2018, Belo Horizonte, Brazil. The International Council of the Aeronautical Sciences, Article ID ICAS2018_0142.
Open this publication in new window or tab >>Comparison of two different indicators for hot cracking in welded structures
2018 (English)In: ICAS 2018: 31st Congress of the International Council of Aeronautical Sciences, The International Council of the Aeronautical Sciences , 2018, article id ICAS2018_0142Conference paper, Published paper (Refereed)
Abstract [en]

Welding simulations of the nickel-based superalloy Alloy 718 have been performed, combined with two fundamentally different hot crack indicators. The purpose of the indicators was to evaluate the risk of hot crack development in the weld. The result of the simulations has been compared with experiments. Advantages and limitations of the two hot crack indicators are discussed. Regions with a high value of the indicators in the simulations agree well with regions with hot cracks in the experiments.

Place, publisher, year, edition, pages
The International Council of the Aeronautical Sciences, 2018
National Category
Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-72832 (URN)2-s2.0-85060474509 (Scopus ID)
Conference
31st Congress of the International Council of the Aeronautical Sciences (ICAS 2018), 9-14 September, 2018, Belo Horizonte, Brazil
Note

ISBN för värdpublikation: 978-3-932182-88-4

Available from: 2019-02-08 Created: 2019-02-08 Last updated: 2023-09-05Bibliographically approved
Olaogun, O., Edberg, J., Lindgren, L.-E., Oluwole, O. & Akinlabi, E. (2018). Modelling and simulation of the first pass in industrial cold rolling process of Aluminium 8015 alloy. In: 11th South African Conference on Computational and Applied Mechanics, SACAM 2018: . Paper presented at 11th South African Conference on Computational and Applied Mechanics (SACAM 2018), Vanderbijlpark, South Africa, September 17-19, 2018 (pp. 314-321). South African Association for Theoretical and Applied Mechanics (SAAM)
Open this publication in new window or tab >>Modelling and simulation of the first pass in industrial cold rolling process of Aluminium 8015 alloy
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2018 (English)In: 11th South African Conference on Computational and Applied Mechanics, SACAM 2018, South African Association for Theoretical and Applied Mechanics (SAAM) , 2018, p. 314-321Conference paper, Published paper (Refereed)
Abstract [en]

The cold rolling process is a strain-hardening mechanism, which is widely known for its strength improvement, excellent surface finish and dimensional tolerance. This work aims to model and simulate the first pass of the industrial cold rolling process of Aluminium 8015 alloy. Process parameters are obtained from practical industrial cold rolling of the aluminium alloy and are used in the development of 2-D and 3-D finite element models for the first pass. These were achieved using the MSC Marc-Mentat Software. Research results comprising of the roll force, contact frictional force, and shear stress were investigated. Findings reveal the deformation rate pattern and neutral points in the roll bite. The 3-D finite element model developed is effective in analyzing deformation of metals in the roll bite as compared to the 2-D model.

Place, publisher, year, edition, pages
South African Association for Theoretical and Applied Mechanics (SAAM), 2018
Keywords
2D/3D FE Model, Aluminium 8015 Alloy, Cold rolling, MSC Marc Mentat
National Category
Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-86246 (URN)2-s2.0-85072929633 (Scopus ID)
Conference
11th South African Conference on Computational and Applied Mechanics (SACAM 2018), Vanderbijlpark, South Africa, September 17-19, 2018
Note

ISBN för värdpublikation: 978-1-77012-143-0; 978-1-77012-144-7;

Finansiär:  University of Johannesburg; The Council for Scientific and Industrial Research (CSIR) South Africa

Available from: 2021-07-02 Created: 2021-07-02 Last updated: 2021-07-02Bibliographically approved
Fisk, M., Lundbäck, A., Edberg, J. & Zhou, J. (2016). Simulation of microstructural evolution during repair welding of an IN718 plate (ed.). Finite elements in analysis and design (Print), 120, 92-101
Open this publication in new window or tab >>Simulation of microstructural evolution during repair welding of an IN718 plate
2016 (English)In: Finite elements in analysis and design (Print), ISSN 0168-874X, E-ISSN 1872-6925, Vol. 120, p. 92-101Article in journal (Refereed) Published
Abstract [en]

A precipitate evolution model based on classical nucleation, growth and coarsening theory is adapted and solved using the multi-class approach for the superalloy IN718. The model accounts for dissolution of precipitates and is implemented in a finite element program. The model is used to simulate precipitate evolution in the fused zone and the adjacent heat affected zone for a welding simulation. The calculated size distribution of precipitates is used to predict Vickers hardness. The simulation model is compared with nanoindentation experiments. The agreement between simulated and measured hardness is good.

National Category
Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-9647 (URN)10.1016/j.finel.2016.07.007 (DOI)000382296400007 ()2-s2.0-84979642371 (Scopus ID)8506a51a-a8b8-470f-a3b1-bb192f2b46fd (Local ID)8506a51a-a8b8-470f-a3b1-bb192f2b46fd (Archive number)8506a51a-a8b8-470f-a3b1-bb192f2b46fd (OAI)
Note

Validerad; 2016; Nivå 2; 20160816 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7298-020x

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