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.

Solidification Process, Microstructure, Density and Hardness of the Mg-Al Alloys with Zn, Cu, Ni and AlTiB Additions

2011 ◽  
Vol 176 ◽  
pp. 91-98
Author(s):  
Franciszek Binczyk
Keyword(s):  
Thermal Analysis ◽  
Regression Analysis ◽  
Operating Temperature ◽  
Solidification Process ◽  
Al Alloys ◽  
Pouring Temperature ◽  
Significance Level ◽  
Solidification Parameters ◽  
Microstructure Density

The paper presents the results of the investigations of the solidification process of magnesium alloys containing 5 and 10 wt.% Al, the additions of Zn, Cu, Ni, and of an AlTiB master alloy. The plotted DTA (derivative thermal analysis) curves were used for the determination of solidification parameters Tliq, Teut and Tsol. Knowledge of these parameters is very important in determination of alloy pouring temperature and maximum casting operating temperature. On samples taken from the area of temperature measurements, the chemical composition and microstructure were determined. The density and hardness HB were measured as well. Applying the method of multiple regression analysis at the significance level α = 0.1, the intensity and direction of the effect of alloying elements on the solidification parameters, density and hardness HB of castings were evaluated.

Study on the Causes and Prevention Measures of Shrinkage Defects of Heavy V-Belt Pulley in the Production

2014 ◽  
Vol 722 ◽  
pp. 231-234
Author(s):  
Gui Qin Jin ◽  
Tao Yan ◽  
Cui Feng Chen
Keyword(s):  
Chemical Composition ◽  
Hot Spot ◽  
Casting Process ◽  
Shrinkage Porosity ◽  
Shrinkage Cavity ◽  
Optimized Design ◽  
Prevention Measures ◽  
Pouring Temperature ◽  
Performance Requirements ◽  
Shrinkage Defects

Shrinkage cavity and shrinkage porosity, often occurring during the production of heavy v-belt pulley roughcast, may lead to the decrease of the pulley performance and further result in casting rejection. Therefore, it is necessary to study the causes and prevention measures of shrinkage defects of the casting. The material of V-belt pulley roughcast at issue is HT250 and it adopts resin sand casting process. With a large amount of practice in workshop and times of revision of the design of foundry technology, we have found that the shrinkage in the hot spot of heavy v-belt pulley roughcast can be reduced or even eliminated to fully meet the performance requirements with a moderate control of pouring temperature and speed, an optimized design of foundry technology, and a strict limitation of chemical composition. This finding will bring illumination to the production process of other heavy pulley roughcast.

Effect of Graphite Degradation on Thermal Analysis Cooling Curve of Ductile Iron Melt

2013 ◽  
Vol 709 ◽  
pp. 153-156
Author(s):  
Li Qiang Wang ◽  
Zhen Hua Li
Keyword(s):  
Thermal Analysis ◽  
Ductile Iron ◽  
Cooling Curve ◽  
Cooling Curves ◽  
Characteristic Temperatures ◽  
Work Characteristic ◽  
Graphite Morphology

In this work, characteristic temperatures of thermal analysis cooling curves of ductile iron melt during fading process were compared, and the graphite morphology of the corresponding samples were studied. Results show that the cooling curves response degradated nodularization promptly, and there are correspondences between the characteristic temperatures of cooling curve and graphite morphology. It indicates that it is feasible to estimate the fading situation of the melt rapidly by identifying the characteristic temperatures of the thermal analysis cooling curves.

scholarly journals Undercooling, Cooling Curves and Nodule Count for Near-eutectic Thin-walled Ductile Iron Castings

2014 ◽  
Vol 54 (2) ◽  
pp. 288-293 ◽  
Author(s):  
Wojciech Kapturkiewicz ◽  
Andriy Burbelko ◽  
Marcin Górny
Keyword(s):  
Ductile Iron ◽  
Cooling Curves ◽  
Nodule Count ◽  
Iron Castings ◽  
Thin Walled

scholarly journals Shaping optimal zinc coating on the surface of high-quality ductile iron casting. Part I – Moulding technologies vs. zinc coating

2017 ◽  
Vol 62 (1) ◽  
pp. 385-390
Author(s):  
A. Szczęsny ◽  
D. Kopyciński ◽  
E. Guzik
Keyword(s):  
Surface Layer ◽  
Ductile Iron ◽  
Metal Matrix ◽  
Surface Condition ◽  
Zinc Coating ◽  
Casting Surface ◽  
Iron Castings ◽  
Coating Formation ◽  
Ductile Iron Casting

Abstract Studies have demonstrated that in the process of hot dip galvanizing the decisive influence on the mechanism of zinc coating formation and properties has the quality of the mechanically untreated (raw) surface layer of the galvanized product. The terms “casting surface layer” denote various parameters of the microstructure, including the type of metal matrix, the number of grains and the size of graphite nodules, possible presence of hard spots (the precipitates of eutectic cementite) and parameters of the surface condition. The completed research has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing.

Effect of Yttrium and Magnesium Segregation on Microstructure and Mechanical Properties of Heavy Section Ductile Iron Castings

2011 ◽  
Vol 295-297 ◽  
pp. 1010-1016 ◽  
Author(s):  
Wei Ping Chen ◽  
Zhe Liu ◽  
Yu Deng ◽  
Jie Luo ◽  
Yong Cheng Chen
Keyword(s):  
Mechanical Properties ◽  
Ductile Iron ◽  
Magnesium Content ◽  
Solidification Mode ◽  
Iron Casting ◽  
Iron Castings ◽  
Microstructure And Mechanical Properties ◽  
Chunky Graphite ◽  
Main Factor ◽  
Ductile Iron Casting

Ductile iron specimen with dimensions of Φ590mm×800mm were prepared by treating the melt with an yttrium-containing nodulizer. Cooling curves at four locations____the center location, the location 85mm distant from the center, the location 170mm distant from the center and the location 255mm distant from the center of the heavy ductile iron casting Φ590mm×800mm was obtained. The effect of yttrium and magnesium on microstructure and mechanical properties was investigated, and the factors on the distribution of chunky graphite in the specimen were discussed as well. The results show that the largest amount of chunky graphite and the lowest mechanical properties appear at the location 170mm distant from the center. Excessive yttrium and magnesium content at the location 170mm distant from the center is the main factor for the large amount of chunky graphite. The characteristics of the solidification mode____pasty solidification and the considerably long solidification of the casting are the basic reasons for the distribution of chunky graphite of the heavy ductile iron casting Φ590mm×800mm.

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.

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