Types Of Cast Iron Research Articles

Perforated Plate for Ballistic Protection—A Review

In recent years, the interest of the scientific community in perforated plates for ballistic protection has increased. Perforated plates do not represent protection by themselves, rather, they are used in the armour systems of armoured vehicles, in conjunction with base armour, since they are intended to induce bend stresses, where a penetrating core fracture occurs. The fragments are subsequently stopped by base armoured vehicle armour. Although for the first time used several decades ago, perforated plates are found to be attractive even today. The main reason is the combination of very convenient properties. Besides high mass effectiveness, they possess a high multi-impact resistance, since their perforations arrest cracks. Therefore, a relatively wide array of materials is suitable for perforated plate fabrication, ranging from alloy steel to some types of cast iron. Being made of metallic materials, raw material costs are relatively low compared to ceramics or composite materials, making them very attractive for present and future armoured vehicles. Finally, armour system consisting of a perforated plate and base plate at some distance, reduce the effectiveness of both shaped charge jets and act as blast mitigators.

Graphite flake cast iron surface hardening

The influence of the operating parameters of electric arc heat treatment of the surface layer of graphite flake cast iron type CП-61 on the structure, microhardness of structural components and the size of the hardening zone is studied. It is shown that controlling the arc power, its speed and the degree of overlap of local hardening zones allows purposefully forming modified structural States with properties most suitable for specific operating conditions in the surface working layer of cast iron. Overlapping of local hardening zones allows purposefully forming modified structures with suitable properties for specific operating conditions in the surface working layer of cast iron rolls. According to the research results, regularities of formation of the structure and phase composition and properties of the surface layer of cast iron type CП-61 under the influence of electric arc heat treatment were obtained. Control of parameters of the processing mode (power and speed of the arc, the degree of overlap of local hardening zones) allows you to purposefully form modified structures with suitable properties for specific operating conditions in the surface working layer of cast iron.

Numerical investigation of the variation of a uniformly dimensioned cast iron property using cooling channels

Cast iron is produced by pouring of smelted metals into a mould, and is differentiated from steel by the carbon content. Different types of cast iron are available, and the properties which are used for distinguishing one from the other are formed based on the chemical composition, liquid treatment, heat treatment, and the cooling rate. The cast iron microstructure is greatly dictated by the graphite size and matrix structure which is primarily influenced by the cooling rate. Cooling rates can make or mar the cast, and are usually varied either with the use of different mould materials or by segmenting the cast. A uniform dimensioned cast with varied properties across its span using the same mould material can be made with the use of cooling channels tailored into the mould. This study seeks to numerically investigate the use of cooling channels to vary the properties of cast iron using the finite element method of solution available in COMSOL Multiphysics. The flow of a cooling fluid through the cooling channels during casting led to different cooling rates across the cast span setting up a temperature differential, an indication of varied properties within it. The cooling rate was observed to be a function of the cooling fluid entry temperature. The properties of a uniformly dimensioned cast iron can be made to vary along its span with the use of a tailored cooling channel in the mould.

Effect of Heating Conditions before Quenching on Residual Stress in High-Speed Steel Type Cast Iron Rolls by Centrifugal Cast

Effect of Heating Conditions before Quenching on Residual Stress in High-Speed Steel Type Cast Iron Rolls by Centrifugal Cast

Combined Material, Pump Design and Manufacturing Method Gives Good Results in Fertilizer Industry

Cost saving is not the best way to achieve good results, but investing in the right products and materials is. Different metallic pump materials and manufacturing methods have been developed for various fertilizer processes. They build on the raw materials used in the production, process conditions in different pumping stages, process know-how, and the material itself. To specify the material of construction based on corrosion resistance alone is not enough, but mechanical properties also need to be considered when selecting pump materials for different pumping stages in the production process for fertilizers. The effect of different components on the abrasion and corrosion resistance in the microstructure of various types of cast irons used in the industry is decisive as well. Pump design features such as flow velocity, wall thickness and seal cavity combined with application knowhow and material selection gives the best result. The development of new coatings and 3D printing technology opens new opportunities for both equipment suppliers and end users.

Effect of Magnesium on the Strength, Stiffness and Toughness of Nodular Cast Iron

Nodular cast iron is a type of cast iron with spheroid graphite surrounded by ferrite matrix and / or pearlite. The size of the graphite and its matrix affects the mechanical properties of the cast iron. This research was conducted to investigate the effect of Magnesium composition on strength, stiffness and toughness of nodular cast iron. Magnesium addition is performed by adding FeSiMg alloys. After that, the composition of magnesium was investigated by using spectrometry. Then tensile test was conducted to obtain the yield strength, tensile strength and modulus of elasticity. Further, impact test was performed to determine the impact energy needed to break the material. The result showed an increase of yield strength, tensile strength and stiffness and a decrease of toughness.

90 years of thermal analysis as a control tool in the melting of cast iron

Since its first literature mention in conjunction with cast iron in 1931 by Esser and Lautenbusch, thermal analysis (TA) has journeyed a long way. Today it is an accepted and widely used tool for process control for all types of cast irons. This paper reviews the latest progress in the development of equipment and analysis methods that make TA successful in applications such as the estimation of chemical composition, graphitization potential, and the shape and number of graphite aggregates. The potential and limitations of the prediction of shrinkage defects propensity are analyzed in some details. Examples of attempts at prediction of mechanical properties and shrinkage propensity are also discussed. Several graphs showing the data scattering are presented to convey the reader a better sense of the accuracy of various predictions.

Thermal conductivity of cast iron -A review

This paper gives a brief introduction to the four research methods for the study on thermal conductivity of cast irons, including experimental measurement, statistical analysis, effective medium theory and numerical simulation. Recent studies on the thermal conductivity of various cast irons are reviewed through the influence of alloying elements, structural constituents, and temperature. The addition of alloying elements is the main reason that restricts the thermal conductivity of cast irons, especially spheroidal graphite cast iron. The connectivity of graphite has a significant effect on the thermal conductivity of flake and compacted graphite cast irons, semiquantitative and quantitative analysis of this factor is a key and difficult point in the study of thermal conductivity of cast irons. The thermal conductivities of different types of cast irons show varying degrees of dependence on temperature. This phenomenon is the combination of graphite and matrix, rather than just depending on graphite morphology. The study of the relationship between individual phase and temperature is the focus of future research. These summaries and discussions may provide reference and guidance for the future research and development of high thermal conductivity cast irons.

Effect of interlamellar spacing on tensile strength gray cast iron with copper variations

Gray cast iron is a type of cast iron which has a flakes graphite forms that have vibration damping properties, as well as good mechanical properties, so this material is widely used in various types of equipment and structures. Addition of necessary elements is one way to improve the mechanical properties of gray cast iron. Giving the portion of copper can increase the formation of graphite on eutectic transformation but reduce the formation of graphite on eutectoid transformation, thereby increasing the amount of pearlite. The results of the SEM (Scanning Electron Microscope) test showed an increased number of pearlites, followed by increasingly interlamellar spacing. Denser interlamellar spacing is obtained by increasing the percentage of a copper element in gray cast iron. The results of tensile testing conducted in this study also showed that an increase in the percentage of copper is able to increase the tensile strength. So, it can be concluded that an increase in the portion of the amount of copper element produces closer interlamellar spacing and increases thereby its tensile strength.

The Effect of Microstructure on Nitriding Mechanism of Cast Iron

Cast irons are widely used in the automotive industry for engine parts due to their excellent casting properties, low cost, high thermal conductivity and mechanical properties. However, the increasingly demanding expectations on an engine necessitate improved mechanical properties and corrosion resistance of cast-iron engine parts. Therefore, the nitriding of cast irons can be considered as a promising surface modification technique. In this paper, the effect of matrix microstructure and graphite morphology on the nitriding mechanism for cast irons was investigated. In the first part; in order to determine the effect of nitriding time, EN-GJV-450 compacted graphite iron samples were gas nitrided at 525 °C, with a nitriding potential value (KN) of 2 atm−1/2 at different periods of nitriding duration of 1, 3 and 6 h. The resultant microstructure characterizations show that with increasing nitriding time, the thickness of the compound layer and nitriding depth increase monotonically. In the second part, the effect of microstructure and graphite morphology on nitriding was examined on three types of cast iron (EN-GJS-500 Nodular, EN-GJV-450 Compacted and EN-GJL-250 Gray) by nitriding at the same temperature and nitriding potential as the first part, but at a nitriding duration of 6 h. The resultant microstructural characterization for the second part revealed that iron nitrides were formed at grain boundaries and around graphite particles, in addition to the surface layer. Nitrogen diffusion paths in cast irons are as follows: grain itself, grain boundaries and graphite boundaries. However, it was observed that nitrogen atoms primarily follow grain boundaries and graphite boundaries. Furthermore, the compacted graphite and gray cast-iron samples have higher nitriding depth than that of nodular cast-iron sample due to 3-D network structure of graphite. Thus, it was concluded that the graphite boundary diffusion was the differentiating factor for the nitriding mechanism in cast irons.

Effect of Heating Conditions before Quenching on Residual Stress in High-Speed Steel Type Cast Iron Rolls by Centrifugal Cast

Effect of Heating Conditions before Quenching on Residual Stress in High-Speed Steel Type Cast Iron Rolls by Centrifugal Cast

Fracture Micromechanisms Evaluation of High-Strength Cast Irons Under Thermomechanical Fatigue Conditions

The truck industry has constantly searched to increase the performance of heavy-duty diesel vehicles, either by reducing weight and the size of the engines, or by increasing their power. In this sense, higher strength grades of cast iron have been developed and tested under thermomechanical conditions, and the results have been positive, since life under such conditions has increased significantly. The purpose of this paper was to shed some light on the fracture micromechanisms acting during crack nucleation and growth under thermomechanical loading conditions, in two cast iron types for use in cylinder head manufacturing, namely gray iron grade 300 (GI 300) and compacted graphite iron grade 500 (CGI 500). The results were compared with those from the standard grades GI 250 and CGI 450. In both gray and compacted graphite irons, fractographic examination showed that the crack starts at graphite tips, grows through the graphite skeleton inside a eutectic cell, and progresses by the coalescence of multiple fatigue cracks from one eutectic cell to another, fracturing the matrix at eutectic cell boundaries. In CGI 500, the graphite in eutectic cells ended with a change in the graphite shape, from vermicular to a round shape end. This brings additional difficulties for the crack propagation process, and, together with the rough interface graphite/matrix and with the thick eutectic cell boundaries, it explains the outstanding thermomechanical results with the CGI 500.

Study the Microstructure and Mechanical Properties of High Chromium White Cast Iron (HCWCI) under Different Martempering Quenching Mediums

The aim of this study is to find an alternative quenching medium for the ordinary nitrate mixture that is cheaper and more available in Iraqi markets. So to obtain the suitable medium , the effect of different quenching mediums used in martempering treatment on the microstructure and mechanical properties of high chromium white cast iron was studied . This type of cast iron is used in mining ,crushing and cement plants as mill liners so it is subjected to extreme conditions of wear and impact that eventually cause failure . In this study, two types of quenching mediums were used in martempering treatment: (50% Sodium hydroxide + 50 % potassium hydroxide) mixture and (50% Sodium nitrate + 50 % potassium nitrate) mixture with different quenching intervals. It is also found that both of the quenching mediums produce higher hardness values at 350°C martempering temperature for 4 hr quenching time ,but there were several advantages and disadvantages associated with using these two different mediums.

Fatigue Properties Of Nodular Cast Irons Alloyed By Si, Mo And Cu

Abstract In recent years, the research of nodular cast iron has been focused on increasing fatigue resistence. In the paper, two types of alloyed nodular cast irons have been investigated – SiMo-nodular cast iron alloyed by 4% of silicon and 1% of molybdenum and SiCu-nodular cast iron alloyed by 4% of silicon and 1.5% of copper. SiMo-nodular cast iron is suitable for high-temperature applications, for example the exhaust manifolds of the combustion engines. SiCu-nodular cast iron is used in various components of tribotechnical units. These components are often loaded by fatigue. The mechanical and fatigue behaviour of both nodular cast iron types has been studied by means of tensile test, impact bending test, hardness test and fatigue tests. Fatigue tests were realised at low frequency cyclic push-pull loading up to 10 million cycles. The relationship between the amplitude of stress and number of cycles to failure was investigated and the fatigue strength was determined. Mechanical and fatigue properties of both nodular cast iron types are correlated with the microstructure of specimens.

New Computer Method of Derivative Thermal Express Analysis of Cast Iron for Operational Prediction of Quality of Melts and Castings

This method is based on the determination of similarity criterion Z as the average temperature difference between the reference and analyzed curves in the solidification region. The purpose of this work is to describe the thermal express-analysis (TDA) device created by us and the substantiation of the reliability and sensitivity of the results of the new method, including the definition of a two-sided confidence interval using Student's t-test. The error of the method was determined with the Student's criterion taken into account. The high sensitivity of the method to the metallurgical prehistory of the gray and white cast iron melts was confirmed. The method has been successfully tested under laboratory and experimental-industrial conditions on induction melting cast iron. The new method uses a disposable environmentally friendly submersible steel sampler with a heat-resistant coating inside and out. The method allows for the quick adaptation to the conditions of specific foundries (especially with the frequent changes of classes and types of cast iron) due to replenishing the database of the reference samples. The basic features of the new method are its universality, self-adaptability, speed, relative simplicity, and high sensitivity to the metallurgical prehistory of molten iron.

Use of Directional Solidification for Improving Tubular Workpiece Quality of Different Cast Irons

A new efficient method of casting tubular billets by directional solidification without the use of a core is proposed making it possible to obtain a fine-grained dense structure of cast iron due to intensive onesided heat removal and excess supply to the solidification front of superheated liquid phase during the entire billet formation time in a metal water-cooled mold (crystallizer). It is shown that the method makes it possible to obtain a prescribed final cast iron structure by creating a certain cooling regime for castings outside the mold. In the positive effect of directional solidification of the melt inherited by iron a decisive role is played by the formation of a dense structure and a more dispersed carbide eutectic with a favorable carbide morphology, which determines the good cast iron wear resistance. The results of studies confirm that the new casting method provides production of workpieces with a prescribed phase composition and improved physical, mechanical, and operating properties. The effect is considered of various factors of the formation of workpieces from different types of cast iron: gray alloyed with lamellar graphite, high-strength and high-chromium, and also Niresist cast iron, on the structure, properties and service life of components for critical purposes of general, mining and oil refining engineering.

Effects of Different Graphite Types on the Thermal Fatigue Behavior of Bionic Laser-Processed Gray Cast Iron

In order to study the thermal fatigue behavior of bionic gray cast iron with different types of graphite (from A to E), first, the effects of A to E types of graphite on the thermal fatigue properties were studied. At the same time, the crack initiation and propagation modes of different gray cast iron types were analyzed. In addition, for improving the thermal fatigue properties of gray cast iron, the anti-fatigue mechanism of the coupled bionic structure on gray cast iron was investigated. In this case, the thermal fatigue properties were measured by the number, length, and width of cracks. The results revealed that the gray cast iron with A-type graphite had the best fatigue resistance compared to others. However, C-, D-, and E-type graphite exhibited the greatest effect on the number, length, and width of crack. Interestingly, the bionic gray cast iron sample with D-type graphite exhibited improved fatigue resistance most obviously compared to the non-bionic sample.

Effect of Different Inoculants on Impact Toughness in High Chromium Cast Iron

AbstractThe present work, presented the study of effect of different inoculants on impact toughness in High Chromium Cast Iron. The molds were pouring in industrial conditions and samples were tested in laboratory in Faculty of Foundry Engineering at AGH. Seven samples were tested - one reference sample, three with different addition of Fe-Ti, and three with different addition of Al. The samples were subjected to impact toughness on Charpy hammer and the hardness test. The presented investigations indicate that for the each inoculant there is an optimal addition at which the sample obtained the highest value of impact toughness. For the Fe-Ti it is 0.66% and for Al is 0.17%. Of all the examined inoculants best results were obtained at a dose of 0.66% Fe-Ti. Titanium is a well-known as a good modifier but very interesting results gives the aluminum. Comparing the results obtained for the Fe-Ti and Al can be seen that in the case of aluminum hardness is more stable. The hardness of all samples is around 40-45 HRC, which is not high for this type of cast iron. Therefore, in future studies it is planned to carry out the heat treatment procedure that may improves hardness.

Effects of Casting Size on Microstructure and Mechanical Properties of Spheroidal and Compacted Graphite Cast Irons: Experimental Results and Comparison with International Standards

The aim of this research was to investigate the effects of casting size (10-210 mm) on the microstructure and mechanical properties of spheroidal (SGI) and compacted (CGI) graphite cast irons. A comparison of the experimental mechanical data with those specified by ISO standards is presented and discussed. The study highlighted that the microstructure and mechanical properties of SGI (also known as ductile or nodular cast iron) are more sensitive to casting size than CGI (also known as vermicular graphite cast irons). In particular, in both types of cast iron, hardness, yield strength and ultimate tensile strength decreased, with increasing casting size, by 27% in SGI and 17% in CGI. Elongation to failure showed, instead, an opposite trend, decreasing from 5 to 3% in CGI, while increasing from 5 to 11% in SGI. These results were related to different microstructures, the ferritic fraction being more sensitive to the casting size in SGI than CGI. Degeneration of spheroidal graphite was observed at casting size above 120 mm. The microstructural similarities between degenerated SGI and CGI suggested the proposal of a unified empirical constitutional law relating the most important microstructural parameters to the ultimate tensile strength. An outstanding result was also the finding that standard specifications underestimated the mechanical properties of both cast irons (in particular SGI) and, moreover, did not take into account their variation with casting size, at thicknesses over 60 mm.

Effect of Copper on the Crystallization Process, Microstructure and Selected Properties of CGI

Abstract The paper presents the results of the research on the effect of copper on the crystallization process, microstructure and selected properties of the compacted graphite iron. Compacted graphite in cast iron was obtained using Inmold process. The study involved the cast iron containing copper at a concentration up to approximately 4%. The effect of copper on the temperature of the eutectic crystallization as well as the temperature of start and finish of the austenite transformation was given. It has been shown that copper increases the maximum temperature of the eutectic transformation approximately by 5°C per 1% Cu, and the temperature of the this transformation finish approximately by 8°C per 1% Cu. This element decreases the temperature of the austenite transformation start approximately by 5°C per 1% Cu, and the finish of this transformation approximately by 6°C per 1% Cu. It was found that in the microstructure of the compacted graphite iron containing about 3.8% Cu, there are still ferrite precipitations near the compacted graphite. The effect of copper on the hardness of cast iron and the pearlite microhardness was given. This stems from the high propensity to direct ferritization of this type of cast iron. It has been shown copper increases the hardness of compacted graphite iron both due to its pearlite forming action as well as because of the increase in the pearlite microhardness (up to approx. 3% Cu). The conducted studies have shown copper increases the hardness of the compacted graphite iron approximately by 35 HB per 1% Cu.