scholarly journals Characteristics of Graphite Precipitates in Aluminium Cast Iron Treated with Cerium Mixture

2015 ◽  
Vol 15 (1) ◽  
pp. 93-98 ◽  
Author(s):  
M. S. Soiński ◽  
A. Jakubus ◽  
K. Skurka
Keyword(s):  
Cast Iron ◽  
Silicon Content ◽  
Unit Area ◽  
Manganese Content ◽  
Aluminium Content ◽  
Al Content ◽  
Compact Graphite ◽  
Image Analyser ◽  
Average Size ◽  
Area Percentage

Abstract The work determined the influence of aluminium in the amount from about 1% to about 7% on the graphite precipitates in cast iron with relatively high silicon content (3.4% to 3.90%) and low manganese content (about 0.1%). The cast iron was spheroidized with cerium mixture and graphitized with ferrosilicon. The performed treatment resulted in occurring of compact graphite precipitates, mainly nodular and vermicular, of various size. The following parameters were determined: the area percentage occupied by graphite, perimeters of graphite precipitates per unit area, and the number of graphite precipitates per unit area. The examinations were performed by means of computer image analyser, taking into account four classes of shape factor. It was found that as the aluminium content in cast iron increases from about 1.1% to about 3.4%, the number of graphite precipitates rises from about 700 to about 1000 per square mm. For higher Al content (4.2% to 6.8%) this number falls within the range of 1300 - 1500 precipitates/mm2. The degree of cast iron spheroidization increases with an increase in aluminium content within the examined range, though when Al content exceeds about 2.8%, the area occupied by graphite decreases. The average size of graphite precipitates is equal to 11-15 μm in cast iron containing aluminium in the quantity from about 1.1% to about 3.4%, and for higher Al content it decreases to about 6 μm.

scholarly journals The Effect of Aluminium on Graphitization of Cast Iron Treated with Cerium Mixture

2014 ◽  
Vol 14 (2) ◽  
pp. 95-100 ◽  
Author(s):  
M. S. Soiński ◽  
A. Jakubus ◽  
P. Kordas ◽  
K. Skurka
Keyword(s):  
Cast Iron ◽  
Silicon Content ◽  
Manganese Content ◽  
Aluminium Content ◽  
High Silicon Content ◽  
High Silicon ◽  
Degree Of Graphitization

Abstract The work determined the influence of aluminium in the amount from about 0.6% to about 8% on graphitization of cast iron with relatively high silicon content (3.4%-3.9%) and low manganese content (about 0.1%). The cast iron was spheroidized with cerium mixture and graphitized with ferrosilicon. It was found that the degree of graphitization increases with an increase in aluminium content in cast iron up to 2.8%, then decreases. Nodular and vermicular graphite precipitates were found after the applied treatment in cast iron containing aluminium in the amount from about 1.9% to about 8%. The Fe3AlCx carbides, increasing brittleness and deteriorating the machinability of cast iron, were not found in cast iron containing up to about 6.8% Al. These carbides were revealed only in cast iron containing about 8% Al.

scholarly journals The Influence of Small Amounts of Aluminium on the Effectiveness of Cast Iron Spheroidization with Magnesium

2013 ◽  
Vol 13 (3) ◽  
pp. 80-83 ◽  
Author(s):  
M. S. Soiński ◽  
A. Jakubus
Keyword(s):  
Cast Iron ◽  
Master Alloy ◽  
Quantitative Assessment ◽  
Aluminium Content ◽  
Flake Graphite ◽  
Matrix Structure ◽  
Image Analyser ◽  
The Matrix ◽  
Aluminium Addition ◽  
Nodular Graphite

Abstract The influence of aluminium added in amounts of about 1.6%, 2.1%, or 2.8% on the effectiveness of cast iron spheroidization with magnesium was determined. The cast iron was melted and treated with FeSiMg7 master alloy under industrial conditions. The metallographic examinations were performed for the separately cast rods of 20 mm diameter. They included the assessment of the shape of graphite precipitates and of the matrix structure. The results allowed to state that the despheroidizing influence of aluminium (introduced in the above mentioned quantities) is the stronger, the higher is the aluminium content in the alloy. The results of examinations carried out by means of a computer image analyser enabled the quantitative assessment of the considered aluminium addition influence. It was found that the despheroidizing influence of aluminium (up to about 2.8%) yields the crystallization of either the deformed nodular graphite precipitates or vermicular graphite precipitates. None of the examined specimens, however, contained the flake graphite precipitates. The results of examinations confirmed the already known opinion that aluminium widens the range of ferrite crystallization.

scholarly journals Effect of Nickel Equivalent on Austenite Transition Ratio in Ni-Mn-Cu Cast Iron

2013 ◽  
Vol 13 (2) ◽  
pp. 53-58 ◽  
Author(s):  
A. Janus ◽  
A. Kurzawa
Keyword(s):  
Cast Iron ◽  
Chemical Composition ◽  
Chemical Analysis ◽  
Wall Thickness ◽  
Brinell Hardness ◽  
Austenite Decomposition ◽  
Structural Components ◽  
Microscopy Image ◽  
Image Analyser ◽  
Nickel Equivalent

Abstract Determined was quantitative effect of nickel equivalent value on austenite decomposition degree during cooling-down castings of Ni-Mn- Cu cast iron. Chemical composition of the alloy was 1.8 to 5.0 % C, 1.3 to 3.0 % Si, 3.1 to 7.7 % Ni, 0.4 to 6.3 % Mn, 0.1 to 4.9 % Cu, 0.14 to 0.16 % P and 0.03 to 0.04 % S. Analysed were castings with representative wall thickness 10, 15 and 20 mm. Scope of the examination comprised chemical analysis (including WDS), microscopic observations (optical and scanning microscopy, image analyser), as well as Brinell hardness and HV microhardness measurements of structural components.

Investigation of Grey Cast Iron Microstructure Influence on its Heat Resistance

2018 ◽  
Vol 284 ◽  
pp. 332-337 ◽  
Author(s):  
Konstantin N. Vdovin ◽  
M.V. Shubina ◽  
I.G. Shubin
Keyword(s):  
Cast Iron ◽  
Heat Resistance ◽  
Thermal Cycling ◽  
Grey Cast Iron ◽  
Matrix Composition ◽  
Compact Graphite ◽  
Grey Cast ◽  
Lamellar Graphite ◽  
Materials Used ◽  
Graphite Inclusions

Grey cast iron is one of the most common engineering materials used to make castings which work in thermal cycling. Under thermal cycling conditions, heat resistance is an important operational property of grey cast iron, which depends to the greatest extent on its structure – size and shape of the graphite inclusions, as well as the metal matrix composition. In this paper, the heat resistance of unalloyed grey cast iron with lamellar and compact graphite distributed in perlitic and perlitic-ferritic metal matrices was determined. The tests were carried out at temperatures of 500 – 800 °C. The results of the studies showed an insignificant difference of perlitic and perlitic-ferritic grey cast iron with lamellar graphite heat resistance. The heat resistance of perlitic ferritic grey cast iron with compact graphite is 16 – 48 % higher than the heat resistance of perlitic ferritic grey cast iron with lamellar graphite. Thus, when the shape of the graphite inclusions changed from lamellar to compact, a significant increase in the heat resistance of unalloyed grey cast iron occurred.

scholarly journals Effect of silicon content and defects on the lifetime of ductile cast iron

2014 ◽  
Vol 12 ◽  
pp. 04006 ◽  
Author(s):  
Akram Alhussein ◽  
Marion Risbet ◽  
Jerome Favergeon
Keyword(s):  
Cast Iron ◽  
Silicon Content ◽  
Ductile Cast Iron

Cast Iron with High Al-Content in Sulfuric Acid

1977 ◽  
Vol 28 (7) ◽  
pp. 480-483 ◽  
Author(s):  
J. N. Defrancq
Keyword(s):  
Cast Iron ◽  
Sulfuric Acid ◽  
Al Content ◽  
High Al Content

Study on Carbothermal Reduction of Titania in Molten Iron

2019 ◽  
Vol 38 (2019) ◽  
pp. 143-150
Author(s):  
Yong Deng ◽  
Jianliang Zhang ◽  
Kexin Jiao
Keyword(s):  
Rate Constants ◽  
Carbothermal Reduction ◽  
Silicon Content ◽  
Arrhenius Equation ◽  
Manganese Content ◽  
Reduction Rate ◽  
Molten Iron ◽  
Titanium Oxides ◽  
Interaction Coefficients ◽  
Iron Powders

AbstractIn order to improve the reduction rate of titania in molten iron, various iron powders containing C, Si, Mn and S were melted. The experiments were carried out on the reduction of titania through a high-temperature tube furnace at 1,723–1,823 K. The quantitative effects of C, Si, Mn, S and temperature on the reduction of titania were investigated in the current study. The results demonstrated that when the carbon content, the manganese content and the temperature increased by 1 %, 0.1 % and 100 K, the reduction rate increased by 0.008 %/h, 0.001125 %/h and 0.0235 %/h, respectively; when the sulfur content increased by 0.01 %, the reduction rate decreased by 0.004875 %/h; the reduction rate was irregular with the change of silicon content in molten iron. The phase at the reaction interface after the experiment was confirmed to be the Fe2Ti3O9 which was considered to be the combination product between iron oxide and titania; the lower titanium oxides were unstable and hard to be observed. The reduction was affected by the concentration of various elements in molten iron and the activity interaction coefficients between various elements. The rate constants for reduction were calculated at 1,723 K, 1,773 K and 1,823 K; the apparent activation energy was calculated as 209 kJ/mol through the rate constants and temperatures according to the Arrhenius equation.

Effects of Nickel substitution by Manganese in Austenitic S.G. Cast Iron for Low-Temperature Uses

1984 ◽  
Vol 34 ◽  
Author(s):  
P. Poyet ◽  
P. Couchinave ◽  
P. I. Dancoisne
Keyword(s):  
Cast Iron ◽  
Low Temperature ◽  
Tensile Properties ◽  
Room Temperature ◽  
Manganese Content ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
Cast Material ◽  
Mechanical Tensile ◽  
High Level

ABSTRACTFor an economical purpose, an austenitic spheroidal graphite cast iron grade, containinq nickel-manganese, has been developed to replace Ni-Resist cast iron, type D2M, for cryogenic applications.Several tests were carried out to produce semi-industrial. heats of 200 kg so as to cast samples with a thickness ranging between 25 and 75 mm, and a variable nickel and manganese content. The resulting grades were compared each other and with Ni-Resist cast irons, before and after heat treatment, for their metallographic structure, their hardness, their mechanical tensile properties at room temperature and their impact values at temperatures down to - 150° C.The results show that it is possible to produce cast iron grades with 7 to 10 % manganese and 9 to 11 % nickel contents, featuring, at quenched state, better mechanical tensile properties at room temperature than Ni- Resist D2M with a 22–25 % Ni content, for roughly equivalent impact values at low temperatures. For as-cast material, the properties obtained vary with material thickness, and ductility is steeply decreasing for thicknesses under 30 mm.Weldability of Ni/Mn cast iron can be compared to Ni-Resist D2M weldability; machinability however seems more difficult, especially when boring quenched material.Generally speaking, the overall properties of these new grades and their lower cost-price if compared to Ni-Resist cast iron, should lead to promising outlets for low temperature uses and/or applications requiring high-level mechanical properties.

Effects of ALPS on Mechanical Property in Bainitic Steels

2014 ◽  
Vol 783-786 ◽  
pp. 926-931 ◽  
Author(s):  
Kiyomichi Nakai ◽  
Sanae Konishi ◽  
Tatsuaki Sakamoto ◽  
Sengo Kobayashi
Keyword(s):  
Unit Area ◽  
Nucleation Site ◽  
The Other ◽  
Dislocation Network ◽  
Slip Systems ◽  
Square Root ◽  
Deformation Strain ◽  
Bainitic Steels ◽  
Average Size ◽  
Strength And Toughness

Aggregate of bainite laths with almost parallel slip systems between neighboring bainite laths, hereafter referred to as ALPS, has great effect on the improvement of mechanical properties in steels. Elongation increases remarkably with increasing the number of bainite laths within an ALPS. When a bainite lath begins to deform, the neighboring bainite lath also easily deforms to relax the deformation strain, because of good parallelism between their slip systems. Under the cooperative deformation of bainite laths, the area of interface between neighboring bainite laths increases during deformation. The increase in the area of interface between neighboring bainite laths suppresses localization of dislocations at the interface, that is, dislocation density per unit area of the interface between neighboring bainite laths hardly increases, resulting in the suppression of nucleation of cracks at the interface between neighboring bainite laths. Ductile fracture would occur along the boundary between ALPSs. It could be suggested that larger ALPS and/or ALPS consisting of large number of bainite laths induce larger elongation in steels.On the other hand, it has been reported that tensile strength increases in proportion to inverse of square root ofd, thedbeing the average size of bainite laths [1]. In order to form fine bainite lath, dislocation network instead of inclusion in austenite was utilized as nucleation site for bainite lath. Great barriers to be overcome exist for the improvement of both strength and toughness. An idea for the improvement of both strength and toughness is shown in this study.

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