scholarly journals EFFECT OF COOLING RATE ON MICROSTRUCTURE AND HARDNESS IN GRAY CAST IRON CASTING PROCESS

2021 ◽  
Vol 27 (3) ◽  
pp. 127-132
Author(s):  
Agus Yulianto ◽  
Rudy Soenoko ◽  
Wahyono Suprapto ◽  
As’ad Sonief
Keyword(s):  
Cast Iron ◽  
Gray Cast Iron ◽  
Thermal Conditions ◽  
Hardness Test ◽  
Casting Process ◽  
Sand Mold ◽  
Gray Cast ◽  
Phase Reaction ◽  
Permanent Mold ◽  
Time Curve

This study aims to investigate the thermal conditions of the molds, changes in microstructure and hardness of casting products using sand mold and permanent mold. The use of sand mold and permanent mold results in different cooling rates. Thermal analysis was performed using a thermocouple to obtain a temperature versus time curve. Metallographic observations were carried out using a Scanning Electron Microscope equipped with Energy-Dispersive X-ray Spectroscopy. The Vickers hardness test was carried out in three areas with different thicknesses. The results showed a constant temperature at 691 oC where the eutectoid phase reaction occurred. Testing with sand mold showed that cast iron with flake graphite was finer and spreader than graphite in cast iron produced by permanent mold. Meanwhile, gray cast iron from a casting process with a permanent mold has a higher hardness than gray cast iron from a casting process using a sand mold.

Microstructure and Hardness of Gray Cast Iron as a Product of Solidification in Permanent Mold

2020 ◽  
Vol 991 ◽  
pp. 37-43
Author(s):  
Agus Yulianto ◽  
Rudy Soenoko ◽  
Wahyono Suprapto ◽  
As’ad Sonief ◽  
Agung Setyo Darmawan ◽  
...  
Keyword(s):  
Cast Iron ◽  
Cooling Rate ◽  
Induction Furnace ◽  
Gray Cast Iron ◽  
Casting Process ◽  
Melting Process ◽  
Gray Cast ◽  
Outer Side ◽  
Permanent Mold ◽  
Test Results

Molds of metal are widely used in the casting process. The cooling rate in solidification of castings product with metal molds on the outer side and inner side is different. Therefore, sizes and types of phase will be also different. This study aims to investigate the microstructure andhardness of gray cast iron. To realize this research, the gray cast iron melting process was carried out in an induction furnace. Melted gray cast iron was poured into a Ferro Casting Ductile mold that has been through a preheating process at a temperature of 300 o C. The gray cast iron is then tested for composition, microstructure and hardness. The test results show that the part containing morecementite phase will be harder.

Simulation of Cooling Rate of Gray Cast Iron Casting in a Sand Mold and its Experimental Validation

2012 ◽  
Vol 710 ◽  
pp. 208-213 ◽  
Author(s):  
Vinod Kumar ◽  
Amitesh Kumar
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Cast Iron ◽  
Cooling Rate ◽  
Gray Cast Iron ◽  
Sand Mold ◽  
Gray Cast ◽  
Flow Heat ◽  
Dendritic Arm Spacing ◽  
Heat Transfer And Solidification

Estimation of cooling rates of gray cast iron casting in the sand mold and its dependency on design and process parameters is one of the keys for achieving best processing conditions to produce quality castings. The estimation of cooling rate involves modeling of fluid flow, heat transfer and solidification of molten metal inside the mold. Prediction of heat transfer has been carried out from filling of mold but the estimation of cooling rate has been carried out after complete filling of the mold. In the present work fluid flow, heat transfer and solidification of molten metal in a sand mold model has been developed on a Pro-Cast 2008 platform. A stepped bar pattern with different thickness has been fabricated to carry out the experiment. Stepped bar pattern has been selected because gray cast iron castings are thickness sensitive as well as different section of castings have different cooling rate. Cooling rates have been determined experimentally by measuring the Dendritic Arm Spacing (DAS) and Secondary Dendritic Arm Spacing (SDAS) from the microstructure of different steps. Results show that the morphology of graphite, dendritic arm spacing and secondary dendritic arm spacing as well as the interlamellar spacing of eutectic structure depend on the casting thickness. These decreases as the thickness of castings decrease because thinner section of casting has higher rate of cooling than the thicker section. The estimated cooling rate matched well with the experimentally measured cooling rate.

A Novel Method for Semi-Solid Casting of Hypereutectic Gray Cast Iron in Expendable Mold

2016 ◽  
Vol 256 ◽  
pp. 237-242
Author(s):  
Safar Rostamzadeh ◽  
Behzad Niroumand ◽  
Ali Maleki
Keyword(s):  
Cast Iron ◽  
Gray Cast Iron ◽  
Solid Phase ◽  
Average Length ◽  
Centrifugal Casting ◽  
Casting Machine ◽  
Sand Mold ◽  
Gray Cast ◽  
Semi Solid ◽  
Control Samples

In the present research, the possibility of single stage semi-solid casting of a hypereutectic gray cast iron in a sand mold was investigated. For this purpose, a specially designed chilled sprue sand mold rigged to a vertical centrifugal casting machine was used. The molten cast iron was poured in the chilled sprue sand mold at 1275 oC at a rotation speed of 400 rpm. Two control samples were also poured at 1275 oC under gravity and centrifugal casting conditions in the same mold without sprue chilling. Microstructures and mechanical properties of the specimens were then characterized. The results showed that the average length and thickness of the primary solid phase, i.e. the Kish graphite, and those of the eutectic flake graphite were smaller in semi-solid centrifuged castings and their hardness were higher than those of the control samples. The results are discussed in terms of the shearing and chilling effects of the designed sprue during the initial stages of pouring.

scholarly journals Improvement of the mechanical properties of nodular gray cast iron with the application of heat treatments

2020 ◽  
Vol 17 (1) ◽  
pp. 21-27
Author(s):  
Ricardo Andrés García-León ◽  
Jhon Herrera-Perea ◽  
Jorge Cerón-Guerrero
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Gray Cast Iron ◽  
Chemical Characterization ◽  
Thermal Conditions ◽  
Heat Treatments ◽  
Gray Cast ◽  
Energy Dispersion Spectrometry ◽  
Different Temperatures ◽  
Physical And Chemical

For this experimental study, commercial samples of nodular gray cast iron were used. Samples were subjected to different heat treatments such as quenching, tempering, and annealing. These treatments were carried out to obtain an increase in specific mechanical properties such as hardness, where the new values of this property were obtained. In this process, different laboratory tests as metallographic characterization, mechanical characterization by Brinell hardness, physical and chemical characterization by Scanning Electron Microscopy (SEM), and X-ray Energy Dispersion Spectrometry (EDS) were applied. The results obtained show that specific thermal treatments can be implemented together and different temperatures, achieving an increase of three times the value of the hardness for the manufacture of brake discs, able to withstand the thermal conditions caused during his operation.  

scholarly journals Obtaining Martensitic Structures during Thixoforming of Hypoeutectic Gray Cast Iron

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Lucas Bertolino Ragazzo ◽  
Davi Munhoz Benati ◽  
Rodolfo Lopez Nadal ◽  
Eugênio José Zoqui
Keyword(s):  
Cast Iron ◽  
Cooling Rate ◽  
Gray Cast Iron ◽  
Liquid Fraction ◽  
Casting Process ◽  
Industrial Applications ◽  
Holding Time ◽  
Gray Cast ◽  
Carbon Equivalent ◽  
Control Of Parameters

The control of parameters such as liquid fraction, holding time, and cooling rate during thixoforming can help control the final microstructure of the thixoformed part, thus improving its mechanical properties. This study intended to investigate conditions required to obtain martensite in hypoeutectic gray cast iron at 3.1% CE (carbon equivalent) deformed in the semisolid state. Samples heated up to 1130, 1135, and 1145°C (liquid fractions of 10, 30, and 45%) were compressed into platens without any holding time (0 s). If a sample presented a martensitic structure for 0 s holding time, new samples were retested at the same temperature for 30, 60, and 90 s holding times. The die casting process was simulated by allowing the platens to become locked after hot compression. Samples that cooled in the locked platens were submitted to higher cooling rates than samples that cooled with the platens open and presented martensite instead of the conventional ferrite and pearlite. Thus, the factor that had the greatest influence on the formation of martensite was the cooling rate rather than stress. The thixoforming process presented good morphological stability, which is highly desirable for industrial applications.

The Lost Foam Casting Simulation of the Gray Cast Iron Linner

2013 ◽  
Vol 834-836 ◽  
pp. 1580-1583
Author(s):  
Shu Heng Yang ◽  
Xiao Ming Du
Keyword(s):  
Cast Iron ◽  
Gray Cast Iron ◽  
Casting Process ◽  
Simulation Method ◽  
Gray Cast ◽  
Lost Foam Casting ◽  
Pouring Temperature ◽  
Technical Parameters ◽  
Lost Foam ◽  
Filling And Solidification

The lost foam casting process of gray cast iron linner was simulated in this paper by using the numerical simulation method to study the properties of the filling and solidification for lost foam casting. And the comparison of the simulated results with the practical casting obtained from foundry was implemented. The results show that the reasonable technical parameters were obtained: pouring temperature of 1400°C, foam density of 13 kg/m3, vacuum of 0.04MPa, coating thickness of 0.5 mm and coating permeability of 9.5×10-9m2/Pa·s.

Teknologi Inokulasi Besi Cor Kelabu FC-250 Untuk Mencegah Pengerasan Pada Dove Tale Produk Ragum Tipe 125

2019 ◽  
Vol 16 (2) ◽  
Author(s):  
Amin Suhadi ◽  
Seodihono
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Treatment Process ◽  
Gray Cast Iron ◽  
Spare Parts ◽  
Gray Cast ◽  
Micro Structure ◽  
Control Factors ◽  
Seed Inoculation ◽  
Casting Industry

Production technology of metal casting industry in Indonesia needs to be improved, especially in the manufacturing of spare parts and box engine made of gray cast iron which has various wall thick such as dove tale construction. Microstructure of gray cast iron is influenced by cooling rate during casting, chemical composition and melting treatment process (inoculation). The part which has the thinnest thickness has the fastest cooling therefore, the grain boundary is smaller compared to other section. As a result this part has highest hardness and difficult to be machined. This research is conducted to solve this problem by modifying melting and solidification treatment process. The research starting from micro structure analysis, composition and mechanical properties tests on the product, and then conducting modification treatment through Taguchi method approach. Experimental results obtained show that the best level settings to control factors which affect to the uniformity of the microstructure and mechanical properties in gray cast iron is the addition of seed inoculation super ® 75, as much as 0.25% with the method of inoculation material entering into the Transfer Ladle.Teknologi produksi pada industri pengecoran di Indonesia masih membutuhkan perbaikan terutama dalam pembuatan komponen mesin perkakas dan peralatan pabrik yang terbuat dari besi tuang kelabu yang mempunyai variasi ketebalan yang besar seperti konstruksi ekor burung (dove tale). Pada pengecoran, struktur mikro dari besi tuang kelabu sangat dipengaruhi oleh kecepatan pendinginan, komposisi kimia dan proses perlakuan pada logam cair (inokulasi). Bagian yang mempunyai ukuran paling tipis mempunyai kecepatan pendinigan paling tinggi karena itu ukuran butirnya jauh lebih kecil dari bagian lain, akibatnya bagian ini mempunyai kekerasan lebih tinggi dan sulit dilakukan pengerjaan mesin. Penelitian ini bertujuan untuk memperbaiki hal ini yang terjadi pada dove taledengan cara memodifikasi proses perlakuan pada cairan besi dan proses pendinginan. Penelitian dimulai dari analisa struktur mikro, pengujian komposisi kimia, pengujian sifat mekanis pada produk kemudian dilakukan modifikasi menggunakan pendekatan metode statistik Taguchi. Hasil penelitian menunjukkan bahwa pengaturan terbaik yang dapat diperoleh untuk mendapatkan keseragaman struktur mikro dan sifat mekanis pada pengecoran besi tuang kelabu adalah penambahan seed inoculation super ® 75, sebesar 0.25% dengan metode pemasukan inokulasi kedalam Ladle pengangkut logam cair.Keywords: carbon, micro structure, hardness, inoculation

MEEHANITE GF-20

Alloy Digest ◽  
1973 ◽  
Vol 22 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Cast Iron ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Gray Cast Iron ◽  
Heat Treating ◽  
Gray Cast

Abstract MEEHANITE GF-20 is a gray cast iron designed principally for high machinability and is used where strength is not an important factor. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: CI-39. Producer or source: Meehanite Metal Corporation.

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