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Svensson, Ingvar L.
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Publications (10 of 175) Show all publications
Kasvayee, K. A., Ciavatta, M., Ghassemali, E., Svensson, I. L. & Jarfors, A. E. .. (2018). Effect of Boron and Cross-Section Thickness on Microstructure and Mechanical Properties of Ductile Iron. Materials Science Forum, 925, 249-256
Open this publication in new window or tab >>Effect of Boron and Cross-Section Thickness on Microstructure and Mechanical Properties of Ductile Iron
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2018 (English)In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 925, p. 249-256Article in journal (Refereed) Published
Abstract [en]

Eeffect of Boron addition on the microstructure and mechanical properties of ductile iron, GJS-500-7 grade was studied. Three cast batches with the Boron content of 10, 49 and 131ppm were cast in a casting geometry containing plates with thicknesses of 7, 15, 30, 50 and 75mm. Microstructure analysis, tensile test, and hardness test were performed on the samples which were machined from the casting plates. Addition of 49 ppm Boron decreased pearlite fraction by an average of 34±6% in all the cast plates. However, minor changes were observed in the pearlite fraction by increasing Boron from 49 to 131 ppm. Variation in the plate thickness did not affect the pearlite fraction. The 0.2% offset yield and ultimate tensile strength was decreased by an average of 11±1% and 18±2%, respectively. Addition of 49 ppm Boron decreased Brinell hardness by 16±1%, while 11±2% reduction was obtained by addition of 131ppm Boron.

Place, publisher, year, edition, pages
Trans Tech Publications, 2018
Keywords
Boron, Component Casting, Ductile Iron, Hardness, Mechanical Properties, Spherical Graphite Iron
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:hj:diva-41056 (URN)10.4028/www.scientific.net/MSF.925.249 (DOI)XYZ ()2-s2.0-85050012940 (Scopus ID)JTHMaterialIS (Local ID)JTHMaterialIS (Archive number)JTHMaterialIS (OAI)
Available from: 2018-07-25 Created: 2018-07-25 Last updated: 2019-01-25Bibliographically approved
Svensson, I. L. & Salomonsson, K. (2018). Mathematical characterization of the tensile deformation curve of cast iron materials. Paper presented at 11th International Symposium on the Science and Processing of Cast Iron, SPCI-XI 2017, Jönköping, Sweden, 4-7 September 2017. Materials Science Forum, 925, 444-450
Open this publication in new window or tab >>Mathematical characterization of the tensile deformation curve of cast iron materials
2018 (English)In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 925, p. 444-450Article in journal (Refereed) Published
Abstract [en]

The manufacturing process gives cast iron castings properties which are dependent on component design, metallurgy and casting method. Factors such as local wall thickness influences the coarseness and type of microstructure and the castings will have local properties depending on the local metallurgical and thermal history. The stress/strain behaviour of cast materials is typically determined by performing a tensile test in a tensile test machine. The deformation behaviour will normally be determined by two mechanisms, namely, elastic and plastic phenomena. The plastic behaviour is based on dislocation movements in the lattice. Commonly, the deformation history of cast iron involves elastic, plastic and crack phases. The cast iron material has a complex microstructure and first order equations cannot be used to predict the deformation during loading. Until methods have been developed, the characterization of complex microstructure materials such as cast iron has to be determined by use of empirical methods. The empirical methods have to couple the internal microstructure and composition of the material with deformation phenomena during loading. The paper will show a method to characterize tensile test curves of cast iron materials which can be used to couple deformation phenomena with for example microstructure. The equations are aimed to make the tensile test curve ready for curve fitting and optimization in two steps. Each stress/strain curve is like a finger print of the material and requires well performed tests and some advices are given. The paper also wants to encourage researchers and people working with tensile testing to get out more of their effort to measure strength of cast iron materials and connect the result to the microstructure of the specimens. 

Place, publisher, year, edition, pages
Trans Tech Publications, 2018
Keywords
Curve fitting methods, Evaluation of, Mathematical curve fitting, Microstructure dependent deformation, Microstructure dependent prediction of tensile test curve, Tensile test curve, Curve fitting, Deformation, Iron compounds, Metallurgy, Microstructure, Stress-strain curves, Tensile testing, Complex microstructures, First order equations, Internal microstructure, Manufacturing process, Mathematical characterization, Mathematical curves, Cast iron
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-41281 (URN)10.4028/www.scientific.net/MSF.925.444 (DOI)XYZ ()2-s2.0-85050025596 (Scopus ID)9783035710557 (ISBN)
Conference
11th International Symposium on the Science and Processing of Cast Iron, SPCI-XI 2017, Jönköping, Sweden, 4-7 September 2017
Available from: 2018-08-28 Created: 2018-08-28 Last updated: 2019-02-15Bibliographically approved
Kasvayee, K. A., Ghassemali, E., Svensson, I. L., Olofsson, J. & Jarfors, A. E. .. (2017). Characterization and modeling of the mechanical behavior of high silicon ductile iron. Materials Science & Engineering: A, 708, 159-170
Open this publication in new window or tab >>Characterization and modeling of the mechanical behavior of high silicon ductile iron
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2017 (English)In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 708, p. 159-170Article in journal (Refereed) Published
Abstract [en]

This paper investigates the effect of the solidification conditions and silicon content on the mechanical properties of ductile iron and presents empirical models for predicting the tensile behavior based on the microstructural characterizations. Two ductile iron grades of GJS-500-7 and GJS-500-14 were cast with silicon content of 2.36% and 3.71%, respectively. The cast geometry consisted of six plates with different thicknesses that provided different cooling rates during the solidification. Microstructure analysis, tensile and hardness tests were performed on the as-cast material. Tensile behavior was characterized by the Ludwigson equation. The tensile fracture surfaces were analyzed to quantify the fraction of porosity. The results showed that graphite content, graphite nodule count, ferrite fraction and yield strength were increased by increasing the silicon content. A higher silicon content resulted in lower work hardening exponent and strength coefficient on the Ludwigson equation. The results for 0.2% offset yield and the Ludwigson equation parameters were modeled based on microstructural characteristics, with influence of silicon content as the main contributing factor. The models were implemented into a casting process simulation to enable prediction of microstructure-based tensile behavior. A good agreement was obtained between measured and simulated tensile behavior, validating the predictions of simulation in cast components with similar microstructural characteristics.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Casting simulation Component casting Ludwigson equation parameters Silicon content Spherical graphite iron
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-36849 (URN)10.1016/j.msea.2017.09.115 (DOI)000415770100016 ()2-s2.0-85030708426 (Scopus ID)
Available from: 2017-08-14 Created: 2017-08-14 Last updated: 2017-12-28Bibliographically approved
Ghasemi, R., Olofsson, J., Jarfors, A. E. W. & Svensson, I. L. (2017). Modelling and simulation of local mechanical properties of high silicon solution-strengthened ferritic compacted graphite iron. International Journal of Cast Metals Research, 30(3), 125-132
Open this publication in new window or tab >>Modelling and simulation of local mechanical properties of high silicon solution-strengthened ferritic compacted graphite iron
2017 (English)In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 30, no 3, p. 125-132Article in journal (Refereed) Published
Abstract [en]

This study focuses on the modelling and simulation of local mechanical properties of compacted graphite iron cast at different section thicknesses and three different levels of silicon, ranging from about 3.6% up to 4.6%. The relationship between tensile properties and microstructure is investigated using microstructural analysis and statistical evaluation. Models are generated using response surface methodology, which reveal that silicon level and nodularity mainly affect tensile strength and 0.2% offset yield strength, while Young′s modulus is primarily affected by nodularity. Increase in Si content improves both the yield and tensile strength, while reduces elongation to failure. Furthermore, mechanical properties enhance substantially in thinner section due to the high nodularity. The obtained models have been implemented into a casting process simulation, which enables prediction of local mechanical properties of castings with complex geometries. Very good agreement is observed between the measured and predicted microstructures and mechanical properties, particularly for thinner sections.

Place, publisher, year, edition, pages
Taylor & Francis, 2017
Keywords
casting process simulation, Compacted graphite iron, materials characterisation, solution-strengthened ferrite, tensile properties, Cast iron, Casting, Ferrite, Ferritic steel, Graphite, Iron, Iron compounds, Mechanical properties, Microstructure, Silicon, Local mechanical properties, Microstructures and mechanical properties, Properties and microstructures, Response surface methodology, Yield and tensile strength, Tensile strength
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-34625 (URN)10.1080/13640461.2016.1261520 (DOI)000400800700001 ()2-s2.0-85006957496 (Scopus ID)
Funder
VINNOVA, DNR 2012_137 2.4.2
Available from: 2017-01-09 Created: 2017-01-09 Last updated: 2017-08-14
Wilberfors, F., Svensson, I. L., Elfsberg, J., Richnau, K. & Ipek, N. (2016). Local chill as a mean of increasing strength in grey cast iron. International Journal of Cast Metals Research, 29(1-2), 40-46
Open this publication in new window or tab >>Local chill as a mean of increasing strength in grey cast iron
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2016 (English)In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 29, no 1-2, p. 40-46Article in journal (Refereed) Published
Abstract [en]

The influence of a chill on the mechanical properties and microstructural features in grey cast iron has been studied. Some of the main findings were that the chill refined the microstructure and modified the graphite distribution from A to D/E. Eutectic cell size was reduced by 60–70%. The Brinell hardness increased while the Vickers hardness, measured in dendrite arms, was unaffected. Fatigue testing in four point bending showed that the fatigue limit was increased by 20–30% in the chilled samples. An increase in tensile strength, proof strength and Young’s modulus was also observed in the chilled samples. The increase in fatigue limit was approximately twice as high as the increase in tensile strength. A possible explanation could be that the eutectic cell size had a more pronounced effect on the fatigue limit than on the tensile strength.

Keywords
Chill, Eutectic cell size, Fatigue limit, Grey cast iron, Mechanical properties, Biomechanics, Cast iron, Chilling, Eutectics, Fatigue testing, Iron, Microstructural evolution, Vickers hardness, Brinell hardness, Dendrite arms, Eutectic cells, Four point bending, Microstructural features, Tensile strength
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-31231 (URN)10.1080/13640461.2016.1142235 (DOI)000377468800007 ()2-s2.0-84978419635 (Scopus ID)
Available from: 2016-08-11 Created: 2016-08-11 Last updated: 2017-11-28Bibliographically approved
Olofsson, J., Salomonsson, K. & Svensson, I. L. (2015). Modelling and simulations of ductile iron solidification-induced variations in mechanical behaviour on component and microstructural level. In: Hideyuki Yasuda, Kyoto University, Japan (Ed.), IOP Conference Series: Materials Science and Engineering, Volume 84: MCWASP XIV: International Conference on Modeling of Casting, Welding and Advanced Solidification Processes: . Paper presented at MCWASP XIV: International Conference on Modeling of Casting, Welding and Advanced Solidification Processes, Awaji island, Hyogo, Japan, 21–26 June, 2015 (pp. 1-8). London: Institute of Physics Publishing (IOPP), 84
Open this publication in new window or tab >>Modelling and simulations of ductile iron solidification-induced variations in mechanical behaviour on component and microstructural level
2015 (English)In: IOP Conference Series: Materials Science and Engineering, Volume 84: MCWASP XIV: International Conference on Modeling of Casting, Welding and Advanced Solidification Processes / [ed] Hideyuki Yasuda, Kyoto University, Japan, London: Institute of Physics Publishing (IOPP), 2015, Vol. 84, p. 1-8Conference paper, Published paper (Refereed)
Abstract [en]

The mechanical behaviour and performance of a ductile iron component is highly dependent on the local variations in solidification conditions during the casting process. Here we show a framework which combine a previously developed closed chain of simulations for cast components with a micro-scale Finite Element Method (FEM) simulation of the behaviour and performance of the microstructure. A casting process simulation, including modelling of solidification and mechanical material characterization, provides the basis for a macro-scale FEM analysis of the component. A critical region is identified to which the micro-scale FEM simulation of a representative microstructure, generated using X-ray tomography, is applied. The mechanical behaviour of the different microstructural phases are determined using a surrogate model based optimisation routine and experimental data. It is discussed that the approach enables a link between solidification- and microstructure-models and simulations of as well component as microstructural behaviour, and can contribute with new understanding regarding the behaviour and performance of different microstructural phases and morphologies in industrial ductile iron components in service.

Place, publisher, year, edition, pages
London: Institute of Physics Publishing (IOPP), 2015
Series
IOP Conference Series, ISSN 1757-8981 ; 84
National Category
Metallurgy and Metallic Materials Applied Mechanics
Identifiers
urn:nbn:se:hj:diva-27783 (URN)10.1088/1757-899X/84/1/012026 (DOI)000357879700026 ()2-s2.0-84939538367 (Scopus ID)
Conference
MCWASP XIV: International Conference on Modeling of Casting, Welding and Advanced Solidification Processes, Awaji island, Hyogo, Japan, 21–26 June, 2015
Available from: 2015-08-27 Created: 2015-08-27 Last updated: 2017-08-14Bibliographically approved
Olofsson, J., Salomonsson, K. & Svensson, I. L. (2015). The multi-scale closed chain of simulations – incorporating local variations in microstructure into finite element simulations. In: TMS 2015 144th Annual Meeting & Exhibition: Supplemental Proceedings. Paper presented at TMS2015, 144th Annual Meeting and Exhibition, Orlando, FL, USA, March 15-19, 2015 (pp. 1057-1064). Springer
Open this publication in new window or tab >>The multi-scale closed chain of simulations – incorporating local variations in microstructure into finite element simulations
2015 (English)In: TMS 2015 144th Annual Meeting & Exhibition: Supplemental Proceedings, Springer, 2015, p. 1057-1064Conference paper, Published paper (Refereed)
Abstract [en]

Numerical simulations of component behavior and performance is critical to develop optimized and robust load-bearing components. The reliability of these simulations depend on the description of the components material behavior, which for e.g. cast and polymeric materials exhibit component specific local variations depending on geometry and manufacturing parameters. Here an extension of a previously presented strategy, the closed chain of simulations for cast components, to predict and incorporate local material data into Finite Element Method (FEM) simulations on multiple scales is shown. Manufacturing process simulation, solidification modelling, material characterization and representative volume elements (RVE) provides the basis for a microstructure-based FEM analysis of component behavior and a simulation of the mechanical behavior of the local microstructure in a critical region. It is discussed that the strategy is applicable not only to cast materials but also to injection molded polymeric materials, and enables a common integrated computational microstructure-based approach to optimized components.

Place, publisher, year, edition, pages
Springer, 2015
Keywords
Multi-scale, Microstructure, Spheroidal Graphite Iron, Ductile Iron, Optimization
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-25170 (URN)
Conference
TMS2015, 144th Annual Meeting and Exhibition, Orlando, FL, USA, March 15-19, 2015
Available from: 2014-11-20 Created: 2014-11-20 Last updated: 2018-09-13Bibliographically approved
Svensson, I. L. & Olofsson, J. (2015). Understanding cast iron materials and components - a never ending story. In: L. Nastac et al. (Ed.), TMS Annual Meeting: Volume 2015. Paper presented at Advances in the Science and Engineering of Casting Solidification: An MPMD Symposium Honoring Doru Michael Stefanescu - TMS 2015 144th Annual Meeting and Exhibition; Walt Disney World, Orlando; United States; 15 March 2015 through 19 March 2015 (pp. 339-346). John Wiley & Sons
Open this publication in new window or tab >>Understanding cast iron materials and components - a never ending story
2015 (English)In: TMS Annual Meeting: Volume 2015, John Wiley & Sons, 2015, p. 339-346Conference paper, Published paper (Refereed)
Abstract [en]

How can an in principal binary alloy of iron and carbon show so many fascinating phenomena and still today give surprises to users, foundrymen and researchers? This paper points out some critical steps in the understanding of the whole chain, from the melt to a cast iron product in service. The understanding of the material is gradually improved, assisted by the advances of other fields, e.g. analyzing methods and computational techniques. The heart in cast iron is the graphite, which is a highly difficult phase to understand but gives the material its unique properties. The linkage between understanding and modelling is necessary to calculate/simulate the processes occurring, where the precipitation, nucleation and growth of the different phases are the keys. Proper nucleation and growth models have been introduced to predict e.g. primary precipitation of austenite and graphite, eutectic growth of different morphologies of graphite or cementite and austenite, solid state transformation of austenite into ferrite and pearlite in both grey and ductile irons, and now gives realistic microstructures and solidification curves for most practical cases. The microstructure formation models gives input to shrinkage and volume calculations to predict porosities, and to predictions of mechanical properties. By linking microstructure formation models, characterization models for mechanical properties and Finite Element Analysis (FEA) it is today possible to use local properties in simulations of the behavior of cast iron components.  

Many phenomena in cast iron, however, still remain unexplained. As one student labelled one of his experimental files on ductile iron, cast iron materials and simulations are indeed a never ending story, with a bright future in industrial applications.

Place, publisher, year, edition, pages
John Wiley & Sons, 2015
Keywords
cast iron, solidification, microstructure, mechanical properties, castings
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-25171 (URN)10.1002/9781119093367.ch40 (DOI)2-s2.0-84931451359 (Scopus ID)9781119082385 (ISBN)9781119093367 (ISBN)
Conference
Advances in the Science and Engineering of Casting Solidification: An MPMD Symposium Honoring Doru Michael Stefanescu - TMS 2015 144th Annual Meeting and Exhibition; Walt Disney World, Orlando; United States; 15 March 2015 through 19 March 2015
Available from: 2014-11-20 Created: 2014-11-20 Last updated: 2018-09-13Bibliographically approved
Olofsson, J., Svensson, I. L., Lava, P. & Debruyne, D. (2014). Characterisation and investigation of local variations in mechanical behaviour in cast aluminium using gradient solidification, Digital Image Correlation and finite element simulation. Materials & Design, 56, 755-762
Open this publication in new window or tab >>Characterisation and investigation of local variations in mechanical behaviour in cast aluminium using gradient solidification, Digital Image Correlation and finite element simulation
2014 (English)In: Materials & Design, ISSN 0261-3069, Vol. 56, p. 755-762Article in journal (Refereed) Published
Abstract [en]

Due to design and process-related factors, there are local variations in the microstructure and mechanical behaviour of cast components. This work establishes a Digital Image Correlation (DIC) based method for characterisation and investigation of the effects of such local variations on the behaviour of a high pressure, die cast (HPDC) aluminium alloy. Plastic behaviour is studied using gradient solidified samples and characterisation models for the parameters of the Hollomon equation are developed, based on microstructural refinement. Samples with controlled microstructural variations are produced and the observed DIC strain field is compared with Finite Element Method (FEM) simulation results. The results show that the DIC based method can be applied to characterise local mechanical behaviour with high accuracy. The microstructural variations are observed to cause a redistribution of strain during tensile loading. This redistribution of strain can be predicted in the FEM simulation by incorporating local mechanical behaviour using the developed characterization model. A homogeneous FEM simulation is unable to predict the observed behaviour. The results motivate the application of a previously proposed simulation strategy, which is able to predict and incorporate local variations in mechanical behaviour into FEM simulations already in the design process for cast components.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Casting, Component behaviour, Mechanical behaviour, Aluminium, Digital Image Correlation, Plastic behaviour, Gjutning, Komponent beteende, Mekaniskt beteende, Aluminium, Digital Image Correlation, Plastiskt beteende.
National Category
Materials Engineering Applied Mechanics Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-22802 (URN)10.1016/j.matdes.2013.12.036 (DOI)000331721100096 ()2-s2.0-84890830495 (Scopus ID)JTHMaterialIS (Local ID)JTHMaterialIS (Archive number)JTHMaterialIS (OAI)
Available from: 2013-12-19 Created: 2013-12-18 Last updated: 2017-08-14Bibliographically approved
Olofsson, J. & Svensson, I. L. (2014). Closed chain simulations of a cast aluminium component - Incorporating casting process simulation and local material characterization into stress-strain simulations. Paper presented at CSSCR 2013: The 3rd International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining, Helsinki (Finland) and Stockholm (Sweden), May 20 - 23, 2013.. ISIJ International, 54(2), 259-265
Open this publication in new window or tab >>Closed chain simulations of a cast aluminium component - Incorporating casting process simulation and local material characterization into stress-strain simulations
2014 (English)In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 54, no 2, p. 259-265Article in journal (Refereed) Published
Abstract [en]

The coupling between simulations of solidification, microstructure and local mechanical behaviour and simulation of stress-strain behaviour is studied by applying a recently developed simulation strategy to a high pressure die cast aluminium component. In the simulation strategy, named a closed chain of simulations for cast components, the mechanical behaviour throughout the component is determined locally by a casting process simulation. The entire casting process, including mould filling and solidification, is simulated to predict the formation of microstructure and residual stresses throughout the component, and material characterization models are applied to relate microstructural features to local elastic and plastic mechanical material behaviour. The local material behaviour is incorporated into a finite element method (FEM) stress-strain simulation of a realistic load case of the component in service.

In the current contribution the influences of local variations in mechanical behaviour and residual stresses on the component behaviour are investigated. The simulation results for local microstructure and mechanical behaviour are compared to experimental results, and the predicted local mechanical behaviour is incorporated on an element level into the FEM simulation. The numerical effect of the variations in mechanical behaviour is quantified by comparing the results achieved using local behaviour and homogeneous behaviour. The influence of residual stresses predicted by the casting process simulation on the component behaviour is also studied.

The casting process simulation is found to accurately predict the local variations in microstructure throughout the component, and the local variations in mechanical behaviour are well described. The numerical results show that casting process simulation and modelling of microstructure formation, material behaviour and residual stresses are important contributions to correctly predict the behaviour of a cast aluminium component in service. This motivates the use of the proposed simulation strategy, and show the importance of incorporating materials science and casting process simulations into structural analyses of cast components. It is discussed that integration of these areas, e.g. using the closed chain of simulations, is important in order to increase the accuracy of FEM simulations and the product development efficiency in the future.

Place, publisher, year, edition, pages
Tokyo, Japan: The Iron and Steel Institute of Japan, 2014
Keywords
FEM simulation, Casting process simulation, Material characterization, Aluminium, High pressure die casting, HPDC., FEM simulering, Gjutsimulering, Materialkaraktärisering, Aluminium, Pressgjutning, HPDC.
National Category
Applied Mechanics Materials Engineering Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-22804 (URN)10.2355/isijinternational.54.259 (DOI)000332682800003 ()2-s2.0-84897052845 (Scopus ID)
Conference
CSSCR 2013: The 3rd International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining, Helsinki (Finland) and Stockholm (Sweden), May 20 - 23, 2013.
Funder
Knowledge Foundation
Note

Special Issue on "Cutting Edge of Computer Simulation of Solidification, Casting and Refining".

Available from: 2013-12-19 Created: 2013-12-18 Last updated: 2017-12-06Bibliographically approved
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