Effects of Iron Powder Addition on the Solidification Behaviour of Hypereutectic Grey Cast Iron

2010 ◽  
Vol 457 ◽  
pp. 90-95 ◽  
Author(s):  
Mihai Chisamera ◽  
Iulian Riposan ◽  
Stelian Stan ◽  
Irina Anton ◽  
Michael Barstow
Keyword(s):  
Thermal Analysis ◽  
Cast Iron ◽  
Iron Powder ◽  
Nucleation Sites ◽  
Solidification Pattern ◽  
Grey Cast ◽  
Powder Addition ◽  
High Cooling Rates ◽  
Eutectic Undercooling ◽  
Commercial Iron

The purpose of the present paper is to investigate the solidification pattern of slightly hypereutectic grey irons (CE = 4.35 - 4.45%) after an addition of a commercial iron powder, and also in a double treatment with inoculation. Chill wedges with a 0.11 - 0.43 cm cooling modulus (CM), from using resin sand and metal moulds, were used along with different thermal analysis cups (CM = 0.75 and 0.43 cm). Relative clear/mottled/total chill measurement criteria were applied. Unfavourable Mn and S contents [(%Mn) x (%S) = 0.016] and a reduced Al residual (0.0015%) led to relatively high eutectic undercooling and chill in the base iron, especially at high cooling rates (CR). With the lower CM of cups, there was more undercooling in the entire solidification range and more difference between irons. Thermal analysis and chill parameter relationships are normal, except only for iron powder treatment and resin mould solidification, where chill is higher for a relatively lower undercooling. Conventional inoculation after addition of iron powder (double treatment) showed a strong graphitizing effect, as these irons had the lowest undercooling and chill levels, in all the irons tested. It reflects the improved properties of (Mn,X)S compounds as nucleation sites for graphite [10]. This paper is the first of two papers reporting on this study.

Influence of Iron Powder Addition on the Structure Characteristics of Hypereutectic Grey Cast Iron

2010 ◽  
Vol 457 ◽  
pp. 96-101
Author(s):  
Mihai Chisamera ◽  
Iulian Riposan ◽  
Stelian Stan ◽  
Cristina Militaru ◽  
Michael Barstow
Keyword(s):  
Iron Powder ◽  
Negative Influence ◽  
Eutectic Cell ◽  
Efficient Treatment ◽  
Beneficial Effects ◽  
Complex Morphology ◽  
Graphite Morphology ◽  
Grey Cast ◽  
Powder Addition ◽  
High Cooling Rates

Slightly hypereutectic grey irons (< 4.5%CE), solidified in resin and metal moulds, after an addition of iron powder, either alone or with Ca,Ba,Al-FeSi inoculation (double treatment) were characterized by structure. Iron powder had a role in limiting the carbide presence, while the supplementary inoculation led to the fewest carbides in metal mould samples. No carbides were in resin mould solidification, while graphite morphology progressed from (C + B) in the base iron up to the type (B + A) in double treated iron. Polygonal (Mn,X)S compounds acting as graphite nuclei, whose characteristics depended on the applied treatment, were found: larger size/low compactness [base iron], irregular polygonal with tendency to the highest size and complex morphology [iron powder treatment] and compact polygonal/smallest size [double treatment]. Iron powder has a negative influence on the graphite nuclei and eutectic cell characteristics, but favours austenite dendrite formation, as a reinforcement for eutectic cells. It has a limited graphitizing effect, witnessed only at high cooling rates. A double addition [iron powder + inoculant] appears to be an efficient treatment, with beneficial effects on both the austenite and graphite nucleation, affecting the final structure and chill tendency.

High Potency Late Inoculation of Grey Cast Iron

2007 ◽  
Vol 23 ◽  
pp. 303-306 ◽  
Author(s):  
Mihai Chisamera ◽  
Iulian Riposan ◽  
Stelian Stan ◽  
C.B. Albu ◽  
C. Brezeanu ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Cast Iron ◽  
Solidification Process ◽  
Solidification Behavior ◽  
High Potency ◽  
Complex Alloy ◽  
First Derivative ◽  
Negative Peak ◽  
Grey Cast ◽  
Eutectic Undercooling

Inoculation comparisons were made between Calcium-bearing FeSi75 and a new complex alloy tablet (CAT) inoculant to compare their effects on late inoculation. Thermal analysis was used to study the solidification behavior and how FeSi75 and the CAT inoculants affect graphite nucleation. Quick-cup addition rates for FeSi75 ranged from 0.1% to 0.3% while the CAT, was added in much smaller amounts, 0.01 to 0.03%. Thermal analysis of the base low sulphur iron (0.02 %S) was characterized by excessive eutectic undercooling. It was found that an addition of 0.03% of the CAT had inoculation efficiency comparable to 0.2% to 0.3% Ca-FeSi75 in reducing the level of undercooling, recalescence and the maximum recalescence rate. A greater negative peak of the first derivative at the end of solidification process, that would minimize micro-shrinkage tendencies, was also obtained.

Investigation and optimization of properties of sintered iron/recycled grey cast iron powder metallurgy parts

2014 ◽  
Vol 229 (6) ◽  
pp. 1010-1020 ◽  
Author(s):  
Hadi Abdollahi ◽  
Ramezanali Mahdavinejad ◽  
Rohallah Panahi Leavoli ◽  
Mohammad Ghambari ◽  
Mahmoud Moradi
Keyword(s):  
Cast Iron ◽  
Powder Metallurgy ◽  
Iron Powder ◽  
Grey Cast Iron ◽  
Sintered Iron ◽  
Grey Cast ◽  
Cast Iron Powder

Influence of Iron Powder Addition on the Number of Primary Austenite Grains and Tensile Strength of Inoculated Cast Iron

2014 ◽  
Vol 790-791 ◽  
pp. 59-64 ◽  
Author(s):  
Dariusz Kopyciński ◽  
Edward Guzik ◽  
Andrzej Szczęsny ◽  
Józef Dorula
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Iron Powder ◽  
Face Centered Cubic ◽  
Iron Particles ◽  
Primary Austenite ◽  
Powder Addition ◽  
Austenite Grains ◽  
Face Centered ◽  
Inoculation Treatment

The study proves that by introducing the iron powder to low-sulphur cast iron still before the inoculation carried out with a conventional graphitising inoculant, the mechanical properties similar to those obtained during the inoculation treatment carried out on cast iron with the recommended high sulphur content are achieved. The said operation increases the number of crystallisation nuclei for of the primary austenite dendrites. In this case, the iron particles act as substrates for the nucleation of primary austenite due to a similar crystallographic behaviour of the regular face centered cubic lattice The more numerous are the dendrites of primary austenite, the less free space is available in the interdendritic spaces for the formation of graphite eutectic grains, which makes the mechanical properties higher.

scholarly journals Competitive Nucleation in Grey Cast Irons

2017 ◽  
Vol 17 (4) ◽  
pp. 185-189 ◽  
Author(s):  
N. Arab
Keyword(s):  
Chemical Composition ◽  
Cell Density ◽  
Cooling Curve ◽  
Eutectic Solidification ◽  
Image Analyzer ◽  
Eutectic Cell ◽  
Cast Irons ◽  
Nucleation Sites ◽  
Grey Cast ◽  
Eutectic Undercooling

AbstractCast irons are good examples of materials which are more sensitive to chemical composition and production conditions. In this research to improve casting quality, solidification and nucleation process in grey cast iron was investigate. In particular, attempts have been made to rationalize variation in eutectic cells with nucleation sites and eutectic solidification undercooling. Four castings with different diameter and similar chemical composition and pouring temperature and different inoculant percentage was casted. The cooling curve and maximum and minimum undercooling for each castings was measured. Also optical metallography and image analyzer has been used to determine the average eutectic cells diameter, and linear and surface densities, and volume density was calculated. The results of this research show a competitive behavior between nucleation sites and eutectic undercooling. Higher nucleation sites and higher eutectic undercooling cause higher eutectic cell density. But increasing nucleation sites by introducing inoculants to molten metal, is accompanied with reduction in eutectic undercooling. It means that inoculation and undercooling have opposite effect on each other. So, to achieve maximum cell density, it is necessary to create an optimization between these parameters.

scholarly journals Methodology of Comparative Validation of Selected Foundry Simulation Codes

2015 ◽  
Vol 15 (4) ◽  
pp. 37-44 ◽  
Author(s):  
Z. Ignaszak ◽  
P. Popielarski ◽  
J. Hajkowski ◽  
E. Codina
Keyword(s):  
Thermal Analysis ◽  
Cast Iron ◽  
Solid Fraction ◽  
Grey Cast Iron ◽  
Simulation Code ◽  
Validation Experiment ◽  
Grey Cast ◽  
Simulation Results ◽  
Simulation Systems ◽  
Comparative Validation

Abstract The validation of each simulation code used in foundry domain requires individual approach due to its specificity. This validation can by elaborated on the basis of experimental results or in particular cases by comparison the simulation results from different codes. The article concerns the influence of grey cast iron density curve and different forms of solid fraction curve Fs=f(T) on the formation of shrinkage discontinuities. Solid fraction curves applying Newtonian Thermal Analysis (NTA) were estimated. The experimental and numerical simulation tests were performed on the castings, which were made with Derivative Thermal Analysis (DerTA) standard cups. The numerical tests were realized using NovaFlow&Solid (NF&S), ProCast and Vulcan codes. In this work, the coupled influence of both curves on the dynamics of the shrinkage-expansion phenomena and on shrinkage defects prognosis in grey cast iron castings has been revealed. The final evaluation of the simulation systems usefulness should be based on validation experiment, preceded by comparing the simulation results of available systems which are proposed in given technology.

Sintering of grey cast iron powder recycled via jet milling

2013 ◽  
Vol 47 ◽  
pp. 174-178 ◽  
Author(s):  
Mahdokht Emadi Shaibani ◽  
Nicolas Eshraghi ◽  
Mohammad Ghambari
Keyword(s):  
Cast Iron ◽  
Iron Powder ◽  
Grey Cast Iron ◽  
Grey Cast ◽  
Jet Milling ◽  
Cast Iron Powder

Solidification Control by Thermal Analysis of La/Ba Inoculated Grey Cast Iron

2015 ◽  
Vol 1128 ◽  
pp. 35-43
Author(s):  
Eduard Marius Stefan ◽  
Mihai Chisamera
Keyword(s):  
Thermal Analysis ◽  
Cast Iron ◽  
Research Work ◽  
Structure And Properties ◽  
Analysis Method ◽  
Cast Irons ◽  
Analysis Technique ◽  
Grey Cast ◽  
Solidification Parameters ◽  
Solidification Control

Thermal analysis is worldwide used in foundry for control of structure and properties of cast irons. In this paper is presented the experimental study realized to control the inoculation effect by thermal analysis method of inoculated grey cast irons. For this purpose was conducted an in ladle inoculation process with 0.5wt. % inoculant from LaCaAlFeSi and BaCaAlFeSi alloy systems. The main goals of this experimental research work are: to determine the particular characteristics of the registered cooling curves, to notice the solidification parameters that present sensibility as against inoculant addition in treated cast iron and eventually to improve thermal analysis technique of cast irons.

Sign in / Sign up

Export Citation Format

Share Document