scholarly journals Cellular Automaton Modeling of Ductile Iron Density Changes at the Solidification Time

2013 ◽  
Vol 13 (4) ◽  
pp. 9-14 ◽  
Author(s):  
A.A. Burbelko ◽  
D. Gurgul ◽  
M. Królikowski ◽  
M. Wróbel
Keyword(s):  
Cast Iron ◽  
Ductile Iron ◽  
Liquidus Temperature ◽  
Temperature Phase ◽  
Casting Alloys ◽  
Iron Castings ◽  
Shrinkage Defects ◽  
Maximum Value ◽  
Three Stages

Abstract Formation of the shrinkage defects in ductile iron castings is far more complicated phenomenon than in other casting alloys. In the paper one of the aspects of formation of porosity in this alloy was considered - changes in cast iron's density during crystallization caused by varying temperature, phase fractions and phase's composition. Computer model, using cellular automata method, for determination of changes in density of ductile iron during crystallization was applied. Simulation of solidification was conducted for 5 Fe-C binarie alloys with ES from 0.9 to 1.1 for the estimation of the eutectic saturation influence on the ductile iron shrinkage and expansion. As a result of calculations it was stated that after undercooling ductile iron below liquidus temperature volumetric changes proceed in three stages: preeutectic shrinkage (minimal in eutectic cast iron), eutectic expansion (maximum value equals to about 1.5% for ES = 1.05) and last shrinkage (about 0.4% in all alloys regardless of ES).

Modelling of the Density Changes of Nodular Cast Iron During Solidification by CA-FD Method

2014 ◽  
Vol 790-791 ◽  
pp. 140-145
Author(s):  
Andriy A. Burbelko ◽  
Daniel Gurgul ◽  
Wojciech Kapturkiewicz ◽  
Edward Guzik
Keyword(s):  
Cast Iron ◽  
Ductile Iron ◽  
Liquidus Temperature ◽  
Nodular Cast Iron ◽  
Solidification Path ◽  
Temperature Phase ◽  
Casting Alloys ◽  
Iron Castings ◽  
Shrinkage Defects ◽  
Three Stages

Formation of the shrinkage defects in ductile iron castings is far more complicated phenomenon than in other casting alloys. In the presented paper changes the ductile iron density during solidification is analyzed. During the solidification path the influence of the temperature, phase fractions and phase composition is taking into account. Computer model, using cellular automata method, for estimation of changes in density of ductile iron during its solidification is applied. Results of the solidification modeling for Fe-C binary alloys with different composition in the castings with a different wall thickness are presented. As a result of calculations it was stated that after undercooling ductile iron below liquidus temperature volumetric changes proceed in three stages: pre-eutectic shrinkage (minimal in eutectic cast iron), eutectic expansion and the last shrinkage.

scholarly journals Influence of Technological Parameters of Furane Mixtures on Shrinkage Creation in Ductile Cast Iron Castings

2014 ◽  
Vol 59 (3) ◽  
pp. 1037-1040 ◽  
Author(s):  
I. Vasková ◽  
M. Hrubovčáková ◽  
J. Malik ◽  
Š. Eperješi
Keyword(s):  
Cast Iron ◽  
Ductile Iron ◽  
Ductile Cast Iron ◽  
Gating System ◽  
Technological Parameters ◽  
Iron Castings ◽  
Steel Castings ◽  
The Impact ◽  
Very High ◽  
Great Development

Abstract Ductile cast iron (GS) has noticed great development in last decades and its boom has no analogue in history humankind. Ductile iron has broaden the use of castings from cast iron into areas, which where exclusively domains for steel castings. Mainly by castings, which weight is very high, is the propensity to shrinkage creation even higher. Shrinkage creation influences mainly material, construction of casting, gating system and mould. Therefore, the main realized experiment was to ascertain the influence of technological parameters of furane mixture on shrinkage creation in castings from ductile iron. Together was poured 12 testing items in 3 moulds forto determine and compare the impact of various technological parameters forms the propensity for shrinkage in the casting of LGG.

scholarly journals Primary Structure and Graphite Nodules in Thin-Walled High-Nickel Ductile Iron Castings

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 649
Author(s):  
Marcin Górny ◽  
Magdalena Kawalec ◽  
Gabriela Sikora ◽  
Ewa Olejnik ◽  
Hugo Lopez
Keyword(s):  
Cast Iron ◽  
Ductile Iron ◽  
Structural Features ◽  
Eutectic Solidification ◽  
Spheroidal Graphite ◽  
Quality Factors ◽  
Iron Castings ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Thin Walled

This paper considers the most important quality factors in processing spheroidal graphite cast iron; namely, primary grains and graphite nodules in thin-walled ductile iron castings (TWDI). In the present study, the effect of grain refinement (by means of Ti, Nb and Zr) and of the holding time after spheroidization and inoculation on effecting the primary grains and eutectic structure in TWDI castings was investigated. Moreover, metallographic examinations (including electron backscattering diffraction, EBSD) were carried out to reveal the macro- and micro-structural features during the primary and eutectic solidification of the cast iron. EBSD results indicate that, within a single dendritic grain, there are numerous boundaries that split the grain into numerous smaller areas. In particular, it is found that the graphite nodules are in contact with the boundaries inside the primary dendritic grain. In turn, crystallization of highly branched dendrites is observed, which seems to “push” the graphite nodules into the interdendritic regions during their growth. The present work investigates the dominant mechanism that gives rise to the primary spheroidal graphite cast iron (SGI) structure. In addition, this work shows that the melt quality is closely associated with the resultant morphology and number of austenite dendrites, graphite nodules, and matrix structure.

Influence of Charge Composition on EN-GJS-500-7 Ductile Iron Properties in Foundry Operating Conditions

2020 ◽  
Vol 998 ◽  
pp. 42-47
Author(s):  
Alena Pribulová ◽  
Peter Futaš ◽  
Marcela Pokusova
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Ductile Iron ◽  
Ductile Cast Iron ◽  
Operating Conditions ◽  
Production Costs ◽  
Steel Scrap ◽  
Charge Composition ◽  
Iron Castings ◽  
Worldwide Production

Worldwide production of ductile iron castings reached in year 2017 26,428,148 metric tons, which is 34% of the total weight of all castings made from cast iron. The most significant increase in ductile iron castings was recorded in Slovakia, up to 78.6%. Castings from ductile iron have a very huge utilization thanks their very good foundry and mechanical properties. The current economic situation in all industries forces entrepreneurs and producers to rationalize production and reduce production costs, with a worldwide trend to increase the share of steel scrap, a technology for the production of ductile cast iron. The paper describes the results of research focused on the effect of charge composition, mainly the share of scrap steel on the final properties and structure of ductile iron EN-GJS-500-7 under the operating conditions of foundry. Six melts with different charge composition were made. The samples from all melts were taken and chemical analysis, microstructure analysis and testing on mechanical properties were made on them. The mechanical properties of produced globular cast irons were according with the relevant standard. It is important to mention that there has been a significant increase in strength characteristics in melts in which the carbon content exceeded 4% (CE = 4.7 and 4.8%, respectively).

scholarly journals Thin Wall Ductile Iron Castings as Substitutes for Aluminium Alloy Castings

2014 ◽  
Vol 59 (2) ◽  
pp. 459-465 ◽  
Author(s):  
E. Fraś ◽  
M. Górny ◽  
H. Lopez
Keyword(s):  
Cast Iron ◽  
Ductile Iron ◽  
Weight Ratio ◽  
Salt Bath ◽  
Thin Wall ◽  
Ratio Increase ◽  
Current Trends ◽  
Iron Castings ◽  
Superior Mechanical Properties ◽  
Alloy Castings

Abstract The paper discusses the reasons behind current trends for substituting cast iron castings by aluminum alloys. In particular it is shown that it is possible to produce thin wall castings (control arms, cantilevers and rotors) made of ductile iron without the development of chills, cold laps or misruns, and with a strength to weight ratio of up 87 MPa cm3/g. In addition, austenitizing at 900 °C for 20 minutes and then austempering in a salt bath at 350 °C for 15 minutes promotes the development of a fully ausferritic matrix in thin wall castings with a the strength to weight ratio increase of up to 154 MPa cm3/g. Finally, it is shown that thin wall castings made of ductile or austemperded cast iron can be lighter and with superior mechanical properties then their substitutes made of aluminum alloy.

Study of Feeding Parameters for the Production of Sound High-Alloyed Ductile Iron Castings with Aluminum

2010 ◽  
Vol 457 ◽  
pp. 261-266
Author(s):  
Vladimir D. Belov ◽  
Edis B. Ten ◽  
Alexander S. Drokin
Keyword(s):  
Cast Iron ◽  
Combustion Engine ◽  
High Heat ◽  
Gray Iron ◽  
High Tendency ◽  
Iron Castings ◽  
Shrinkage Defects ◽  
Feeding Parameters ◽  
Casting Production ◽  
High Aluminum

This work deals with the problem of casting production from high-aluminum cast iron Al22D. This cast iron is characterized by unique combination of properties [1-3]: high heat-resistance in corrosive gases medium especially containing sulfurous gases; relatively low density in comparison with gray iron and satisfactory mechanical properties. In addition, castings made from high aluminum cast iron Al22D are required in many areas of mechanical engineering. However, obtaining high-quality products from this cast iron is a particular problem due to its low-casting properties, especially its high tendency to gas saturation, oxidization and forming scabs, shrinkage and gas-shrinkage defects. Therefore, the aim of this work is the study of the castings feeding parameters. In addition, the technology of "exhaust manifold" casting of internal combustion engine designed to work in forced mode was developed on the basis of the obtained results.

A Study on Ductile Iron Production without the Use of Feeders

2010 ◽  
Vol 457 ◽  
pp. 499-504
Author(s):  
Vasilios Fourlakidis
Keyword(s):  
Thermal Analysis ◽  
Ductile Iron ◽  
Shrinkage Porosity ◽  
Cooling Curves ◽  
Pouring Temperature ◽  
Iron Castings ◽  
Shrinkage Defects ◽  
Microstructure Examination ◽  
Solidification Parameters ◽  
Ductile Iron Casting

This paper investigates the effects of graphite added as a conditioner, of Lantanum containing nodulariser and of pouring temperature on the formation of shrinkage porosity in ductile iron casting with an eutectic composition. In this experiment for each heat the cooling curves were recorded by the use of Quick-Cups (thermal analysis cups) and different solidification parameters such as TElow, GRF1, GRF2 and TS were calculated and compared with the porosity which was found from the microstructure examination. The results show that there is a good correlation between the amount of the shrinkage formation and the thermal analysis values. Also this experiment confirm that by using certain treating elements and pouring temperature which was between 1340-1350°C it is possible to eliminate the shrinkage defects in ductile iron castings without using feeders.

scholarly journals The Impact of Process Factors on Creating Defects, Mainly Lustrous Carbon, during the Production of Ductile Iron Using the Lost-Foam Casting (LFC) Method

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1022
Author(s):  
Jan Jezierski ◽  
Michał Jureczko ◽  
Rafał Dojka
Keyword(s):  
Cast Iron ◽  
Ductile Iron ◽  
Surface Defects ◽  
Ductile Cast Iron ◽  
High Tech ◽  
Lost Foam Casting ◽  
Iron Castings ◽  
Process Factors ◽  
The Impact ◽  
Lost Foam

The purpose of this paper was to analyze the process factors affecting the occurrence of lustrous carbon defects in ductile cast iron castings when using the lost-foam casting (LFC) method. This phenomenon results in creating raw surface defects, which sometimes may even lead to cast iron scrapping. A series of trial melting batches were carried out for variable process assumptions. The analysis was performed to reflect, to the greatest extent possible, real foundry production conditions. Industrial tests were performed in Odlewnia Rafamet Sp. z o.o., Kuźnia Raciborska, Poland. The polystyrene patterns created by gluing components together, used in the tests, met the requirements of the high-tech lost-foam casting (LFC) process. The performed analysis allowed the obtaining of lustrous carbon defects in test castings as well as the determination of the process parameters with the highest impact on lustrous carbon inclusions in ductile iron castings. The test results were used to eliminate the possibility of creating a defect and thus directly improve the efficiency of the lost-foam casting (LFC) process used in the foundry.

scholarly journals Validation Tests of Prediction Modules of Shrinkage Defects in Cast Iron Sample

2017 ◽  
Vol 17 (1) ◽  
pp. 57-66 ◽  
Author(s):  
J. Hajkowski ◽  
P. Roquet ◽  
M. Khamashta ◽  
E. Codina ◽  
Z. Ignaszak
Keyword(s):  
Cast Iron ◽  
Cast Alloy ◽  
Processing Parameters ◽  
Standard Test ◽  
Experimental Simulation ◽  
Simulation Code ◽  
Iron Castings ◽  
Shrinkage Defects ◽  
Iron Sample ◽  
Validation Tests

Abstract The paper presents the results of experimental-simulation tests of expansion-shrinkage phenomena occurring in cast iron castings. The tests were based on the standard test for inspecting the tendency of steel-carbon alloys to create compacted discontinuities of the pipe shrinkage type. The cast alloy was a high-silicone ductile iron of GJS - 600 - 10 grade. The validation regarding correctness of prognoses of the shrinkage defects was applied mostly to the simulation code (system) NovaFlow & Solid CV (NFS CV). The obtained results were referred to the results obtained using the Procast system (macro- and micromodel). The analysis of sensitivity of the modules responsible for predicting the shrinkage discontinuities on selected pre-processing parameters was performed, focusing mostly on critical fractions concerning the feeding flows (mass and capillary) and variation of initial temperature of the alloy in the mould and heat transfer coefficient (HTC) on the casting - chill interface.

scholarly journals Casting Ductile Iron in Layer Moulds Made from Ecological Sands

2012 ◽  
Vol 12 (3) ◽  
pp. 99-104
Author(s):  
M. Rączka ◽  
K. Gandurski ◽  
B. Isendorf
Keyword(s):  
Cast Iron ◽  
Ductile Iron ◽  
Effective Means ◽  
Organic Binder ◽  
High Quality ◽  
Iron Castings ◽  
Simplified Method ◽  
Core Sand ◽  
Geopolymer Binder ◽  
Feeding Systems

Abstract The article contains the results of tests performed under the target project in Hardtop Foundry Charsznica. The objective of the tests and studies was to develop a technology of making high-quality ductile iron castings, combined with effective means of environmental protection. The studies presented in this article related to castings weighing from 1 to 300 kg made from ductile iron of grades 400-15 and 500-7, using two-layer moulds, where the facing and core sand was the sand with an alkaline organic binder, while backing sand was the sand with an inorganic geopolymer binder. A simplified method of sand reclamation was applied with possible reuse of the reclaim as an addition to the backing sand. The cast iron spheroidising treatment and inoculation were selected taking into account the specific conditions of Hardtop Foundry. A pilot batch of castings was made, testing the gating and feeding systems and using exothermic sleeves on risers. The study confirmed the validity of the adopted concept of making ductile iron castings in layer moulds, while maintaining the content of sand with an organic binder at a level of maximum 15%.

Sign in / Sign up

Export Citation Format

Share Document