Types Of Cast Iron Research Articles

Influence of Mo and W on Solidification Microstructure Formation for Ni-hard Type Cast Iron

Influence of Mo and W on Solidification Microstructure Formation for Ni-hard Type Cast Iron

A comparative study of flake graphite iron and compacted graphite iron in austempered condition for directional control valves

Demand for lighter materials with the right qualities is unavoidable in the present era of engineering. Compacted graphite iron is a type of cast iron gaining momentum nowadays in foundries due to its distinct characteristics that fall between gray cast iron/flake graphite iron and spheroidal graphite iron. It becomes the right candidate to replace flake graphite iron in many applications. In this research, flake graphite iron (FC −30) and compacted graphite iron-300 grades were studied to enhance its properties through austempering heat treatment process. Initially, the as-cast (non-austempered) flake graphite iron and compacted graphite iron were subjected to microstructural study and mechanical testing. Subsequently, the flake graphite iron and compacted graphite iron were subjected to austempering heat treatment. The various austempering temperatures selected are 270, 320, and 370 °C for different soaking time periods of 30, 60, 90, and 120 min. As cast flake graphite iron specimen (FC-30) exhibited lesser tensile strength (293 N/mm2) than as cast compacted graphite iron (528 N/mm2) and austempered compacted graphite iron (652 N/mm2). With respect to hardness measurement, austempered compacted graphite iron specimens yielded higher hardness of up to 415 BHN. However, the compacted graphite iron specimen austempered at 370 °C for 90 min measured an optimum hardness value of 373 BHN and tensile strength of 630 N/mm2 with less retained austenite (0.3%). This hardness value is considered to be more suitable in machining operation for making hydraulic directional control valves exposed to constant abrasion.

Explosive Welding of Aluminum and Cast Iron for Potential Transportation and Structural Applications

This study explores the feasibility of explosive welding to join dissimilar materials: aluminum (JIS A1050‐H24) and two cast iron types (JIS G 5501 and JIS G 5502), which are challenging to weld due to the presence of graphite in the cast iron. Further, the impact of explosive thickness (28, 38, and 47 mm) on weld quality is investigated, considering microstructure and mechanical behavior. Increasing explosive thickness correlates with a thicker local melted zone. Remarkably, in investigations, a novel morphology that diverges from conventional patterns is observed. The weld interface of explosively bonded materials exhibits anchor formation, a unique interlocking structure. These anchors play a significant role in establishing a robust mechanism between bonded surfaces. JIS A1050‐H24 shows minimal hardness variation, while cast iron exhibits significant variations with increased explosive thickness. Tensile shear tests showcase robust clad plate strength, with fractures primarily in JIS A1050‐H24 regions instead of at the interface. The highest tensile shear strength is achieved with an explosive thickness of 38 mm. Overall, explosive welding of aluminum with cast iron creates a strong, durable, and lightweight material with enhanced performance characteristics, making it promising for diverse industrial applications due to its outstanding properties.

Influence of alloying elements and its effect on austempering of compacted graphite iron – A review

Compacted Graphite Iron (CGI) is a type of cast iron with intermediate properties between grey and ductile cast iron. The vermicular graphite structure in the CGI provides unique properties to manufacture automotive and other engineering components. However, because of its narrow range of metallurgical control, a high volume of CGI production is not attempted in many foundries. The addition of alloying elements and austempering heat treatment process has a significant effect in altering the properties and microstructure of CGI. Hence, the objective of this paper is to review the influence of various alloying elements and austempering processes in manufacturing CGI components. Eventually, the scope for the research on the development of austempered CGI is identified.

Experimental Research Regarding the Effect of Mineral Aggregates on the Wear of Mixing Blades of Concrete Mixers.

Industrial mixers are equipment used to mechanically combine different types of materials in order to obtain homogeneous mixtures. In concrete industry production, mixers play a crucial role by facilitating the efficient and consistent blending of various constituents to create high-quality concrete. Because the mixers in the concrete industry work in conditions characterized by abrasive and erosive loadings, the authors of this paper tried to establish a dependence between the quality of the material from which the mixing elements are made and their wear resistance. Three types of cast irons alloyed with chromium, specific to the construction of mixing blades, were used in this research. The working environment was a mixture of crushed mineral aggregates corresponding to the granulometric class 4-8 mm. The tests were carried out on an experimental stand designed and built by the authors of this paper. The stand reproduces on a scale of 1:2 a drum made up of a double-axis horizontal mixer. The stand had the possibility to change the value of the attack angle of the mixing blades, corresponding to the following values: 30, 45, and 60 degrees. The results of the tests established the dependence between the type of material and the wear rate of the blades as well as the influence exerted by the angle of attack on the wear of the mixing blades. It was shown that when the inclination angle of the blade relative to the shaft axis increases, the cumulative mass loss decreases, with values between 43% and 55.83%, as a function of the quality of blade material.

Influence of Structural Parameters - the Shape of Graphite and Matrix on Change of Ultrasonic Wave Propagation Rate and Value of Attenuation in Graphitic Cast Irons

Abstract Despite the tendency of the current industry, especially the automotive industry, it is to use modern, light and super-strong materials based on Al or HSLA steels, the application of classic materials such as cast iron still makes sense, especially concerning price and excellent castability. The article presents one of the possible ways of using the ultrasonic non-destructive method in quality control and simplification of the identification of the type of cast iron concerning the change of parameters of ultrasound propagation in materials. The main criteria for assessing the quality and determining the type of graphite cast iron were considered to be the rate of propagation of ultrasound - cL and the value of attenuation - α, which vary depending on the shape of the graphite and matrix. Graphitic cast irons with different graphite shapes (lamellar, vermicular, and globular shapes) and a matrix with different ferrite/perlite ratios were used as experimental material. Along with the ultrasonic tests, a metallographic analysis was also performed to quantify the microstructure of cast irons.

Effect of increased mechanical strength on the machinability of graphite cast irons in face milling

Due to the low cost and high vibration damping capacity, gray cast irons are commonly used in machine tool bases, in addition to applications with noise restrictions, such as engine blocks, housings, and brakes. The matrix’s graphite, sulfides, and ferrite/pearlite ratio are some of the most important parameters governing the machinability of the gray cast irons. This work aims to evaluate the machinability of high-resistance gray cast irons of the FC 300 grade, in two versions, with the addition of molybdenum (FC 300 (Mo)) and with refined graphite and addition of molybdenum (FC 300 (Mo+RG)), for use in cylinder heads and engines blocks, compared to materials that have been used for this purpose, gray cast iron FC 250 and the compacted graphite cast iron FV 450. The materials were characterized according to the cementite interlayer spacing and microhardness of the perlite matrix, the number of eutectic cells, and the distribution of manganese sulfide inclusions, with those characterizations being correlated with the machinability results. The face milling process was chosen for the tests with uncoated cemented carbide tools without cutting fluids; the cutting speed and feed rate varied in addition to the type of cast iron. Analysis of tool life, wear mechanisms, and machined surfaces’ quality (Ra roughness parameter) were the output variables considered. Using harder materials such as FC 300 (Mo) or FC 300 (Mo+RG) for the engine would bring benefits such as increased durability, reduced weight, and improved efficiency, but it has a cost in machining. These harder materials have a shorter tool life compared to the commonly used gray cast iron FC 250, but the difference in performance is less pronounced under more extreme cutting conditions, such as high cutting speed and feed rate. When analyzing the surface roughness, FC 250 produced a smoother surface at low cutting speeds but performed worse than FC 300 (Mo) and FC 300 (Mo+RG) at higher cutting speeds.

Indentation fracture toughness of boronized unalloyed and alloyed ductile iron

This study was carried out to investigate the fracture toughness of boride layers in ductile irons using a Vickers indentation method and to demonstrate the method's reliability. For this purpose, alloyed (Cu, Ni, and Mo) and unalloyed ductile cast irons were borided for 2, 4, 6, and 8 h at 900 and 950 °C temperatures. The morphology of the boride layer was studied using an optical microscope. The hardness profiles and thicknesses of the boride layers were measured. Boron compounds were discovered using the X-ray diffraction method. The fracture toughness of the boride layer was tested using the Vickers indentation method under a 300g load. In unalloyed cast iron, the surface hardnesses obtained by boriding were 5, 45-6, 69 times higher than that of the unboronized iron hardness. In general, alloyed iron produces thicker boride layers under the same boriding parameters. Depending on the boriding time, the fracture toughness increased at 900 °C and decreased at 950 °C in both types of cast iron.

ANALYSIS OF THE MECHANICAL PROPERTIES OF LONG PRODUCT ROLLING MILL ROLLS

Rolls of longproduct rolling mills, as an expendable working tool of the rolling technological operation, make up a significant share of redistribution costs and significantly affect the economic efficiency of the manufacturing process. The importance of rolls is manifested in the organization of their production at specialized enterprises, the presence of rolling menage in the workshops of metallurgical enterprises, the development and introduction of new rolling rolls materials. Therefore, the tasks of analyzing the available roll materials and their properties, choosing the optimal set of properties for the conditions of a certain state become quite actual.
 The purpose of the work is to review rolled materials and analyze the properties of rolls used in modern long-product mills. Such an analysis was performed for steel and cast-iron rolls, the use of which is most common on mills for the production of simple profiles in the form of bars and rods.
 Based on the analysis of the latest research and publications, the stages of the development of rolled materials in retrospect, the main indicators of the mechanical, technological and operational properties of the rolls have been determined. The main types of cast iron and steel rolling materials offered by leading manufacturers of rolling rolls are also established. For these groups of roll materials, an analysis of their mechanical properties, such as hardness, tensile strength, and bending strength, was performed.
 Based on the results of the analysis, a significant improvement in the mechanical and operational properties of modern rolled materials was noted. This is achieved due to alloying, improvement of their manufacturing technologies, specialized types of heat treatment aimed at forming a certain structure and properties. Conditional blurring of boundaries between cast iron and steel rolls is also established. For example, iron rolls with a ferrite structure and spheroidal graphite and graphitized steel rolls are used, which provide approximately the same mechanical strength, gripping ability and wear resistance.
 Modern rolled materials are characterized by the expansion of controlled property indicators. This applies both to the components of the chemical composition and to indicators of mechanical properties. In particular, the leading manufacturers of rolled rolls include the bending strength limit, which is 1.5 to 2 times higher than the strength limit from tensile tests, among the mandatory indicators.
 In the calculations of the rolls, the fulfillment of their strength conditions should be checked by the allowable stresses determined beyond the bending strength limit, as an indicator of the properties, which to a greater extent corresponds to the load conditions of the rolls.
 An objective assessment of the performance of the rolls according to the strength conditions can be obtained only when determining the allowable stresses based on the actual values of the properties provided by the manufacturer of the rolls, and not according to the range of values recommended in the literature.
 The results of the conducted analysis can be used for the justified selection of rolling materials, improving the control of their properties, obtaining objective assessments of their performance, increasing the efficiency of the rolling farm and technical and economic indicators of production processes.

Enhancement of Mechanical Properties and Corrosion Resistance of Cast Iron Alloy Using CO2 Laser Surface Treatment

This work aimed to study the effect of laser surface treatment on the mechanical characteristics and corrosion behaviour of grey cast iron type A159. Many technical applications used conventional surface treatment, but laser surface hardening has recently been used to enhance the surface properties of many alloys. The mechanical characteristics, including microstructure, microhardness, and wear resistance of A159 grey cast iron, were studied, in addition to corrosion behaviour. The experimental laser parameters in this work were 0.9, 1.2, and 1.5 KW power with continuous wave carbon dioxide lasers with scanning speeds of 10 and 12 mm/s were used. The results found that phase-transitional alterations in microstructure were influenced by laser therapy. Also, the microhardness increased with increasing power, with the maximum reaching approximately 950 HV while the base metal has an average of approximately 260 HV. Also, we found the power laser increased corrosion resistance by lowering the corrosion rate (CR) from 21.10 for the untreated sample to 1.02 (m.p.y.), additionally, corrosion protection efficiency (CPE) increased to 95.27 percent. On the other hand, the wear test revealed that mass loss decreased as laser surface treatment power increased; it reached 0.19 g for the laser-treated samples, compared to 1.25 g for the base metal after the 50th minute of the wear experiment.

Data-Driven Model Selection for Compacted Graphite Iron Microstructure Prediction

Compacted graphite iron (CGI), having a specific graphite form with a large matrix contact surface, is a unique casting material. This type of cast iron tends to favor direct ferritization and is characterized by a complex of very interesting properties. Intelligent computing tools such as artificial neural networks (ANNs) are used as predictive modeling tools, allowing their users to forecast the microstructure of the tested cast iron at the level of computer simulation. This paper presents the process of the development of a metamodel for the selection of a neural network appropriate for a specific chemical composition. Predefined models for the specific composition have better precision, and the initial selection provides the user with automation of reasoning and prediction. Automation of the prediction is based on the rules obtained from the decision tree, which classifies the type of microstructure. In turn, the type of microstructure was obtained by clustering objects of different chemical composition. The authors propose modeling the prediction of the volume fraction of phases in the CGI microstructure in a three-step procedure. In the first phase, k-means, unsupervised segmentation techniques were used to determine the metamodel (DT), which in the second phase enables the selection of the appropriate ANN submodel (third phase).

ACO EUROBAR EN-GJL-300C (5.1308)

Abstract ACO Eurobar EN-GJL-300C (5.1308) is a higher-tensile-strength gray cast iron that is produced by the continuous casting process. It provides a combination of high strength while still maintaining good thermal conductivity compared with other types of cast iron. This grade approaches the maximum tensile strength attainable in gray cast iron. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, and tensile properties. It also includes information on wear resistance as well as heat treating and machining. Filing Code: CI-99. Producer or source: ACO Eurobar GmbH (a subsidiary of ACO Guss GmbH).

The application of deep neural networks for the classification of the microstructure of cast iron products

The possibilities of using artificial neural networks in the tasks of recognizing the microstructure of cast irons have been investigated. Convolutional neural networks work on the basis of filters that are concerned with recognizing certain characteristics of an image (for example, straight lines). A filter is a collection of kernels; sometimes a single kernel is used in a filter. A kernel is a common matrix of numbers called weights that are "trained" in order to search for certain characteristics in images. The filter moves along the image and determines if some desired characteristic is present in a particular part of it. To obtain an answer of this kind, a convolution operation is performed, which is the sum of the products of the filter elements and the matrix of input signals. If some desired characteristic is present in the image fragment, the convolution operation will produce a number with a relatively large value at the output. If the characteristic is absent, the output number will be small. Note that the number of filter channels must match the number of channels in the original image; only then will the convolution operation produce the desired effect. For example, if the original image consists of three channels, the filter must also have three channels. The structure (architecture) of the convolutional neural network was proposed and its ability to recognize the presence of structural components of the microstructure of cast iron was confirmed. The training of the network was performed on images of microslices of various types of cast iron, and positive results were achieved with an accuracy close to 85%. The results of the work indicate the prospects of using convolutional neural networks in the tasks of recognizing and classifying the microstructure of cast iron.

High-temperature deformation and interfacial damage in CGI: 3D numerical analysis

Compacted graphite iron (CGI), a type of cast iron, forms an integral part of the industry worldwide thanks to its good thermal and mechanical properties, excellent wear resistance, and competitive price. Despite the extensive research on cast irons since the 1950s, their thermomechanical behaviour and, especially, their fracture at the microscale is not yet fully understood. Interfacial debonding is the main mechanism of fracture in compacted graphite iron. Such features of interfacial-debonding initiation, thermal interfacial damage and deformation between graphite inclusions and a surrounding matrix are investigated in this work. A three-dimensional unit cell comprising the matrix and a graphite inclusion is developed to simulate thermal deformation and damage under pure thermal loading; both phases were assumed to have elastoplastic behaviours. Different fracture mechanisms were analysed under fully fixed and periodic boundary conditions. The results could provide a deeper understanding of the mechanisms of thermal deformation and fracture in compacted graphite iron.

Design, analysis, and optimization of thresher machine flywheel using Solidworks simulation

In this study, the effects of flywheel geometry and materials are considered in terms of stresses and deformation. Conventionally, the thresher machine uses a solid disk-type cast iron flywheel. Specifically, this paper investigates whether this is the most efficient geometry and material for the thresher machine, and whether there is scope for further improvement by changing its geometry and material. Engineering designs can be analyzed and optimized for determining various parameters like von mises stress and deformation using finite element analysis. Solidworks analysis is carried out for 6 spoke rim type and solid disc-type flywheels and maximum von-misses stresses and deformation are determined and compared for both. S-glass fiber and grey cast iron materials are used for FEA. This research shows that a good geometric design of the flywheel and selection of correct material can improve its energy storage capacity for the thresher machine. It is observed that stress values on cast iron flywheel with the solid disc due to centrifugal loading is higher but deformation was lower. Therefore, if we can compensate deformation, an alternative to conventional solid/disc type cast iron flywheel is solid/disk type S-glass fiber flywheel in thresher machines.

STUDY OF THE SUITABILITY OF VARIOUS TYPES OF CASTING MATERIALS FOR THE MANUFACTURE OF A SHIP ENGINE

The objective of this work was to study the suitability of three types of cast iron for the manufacture of a ship engine: EN-GJS-500-7U for the manufacture of the engine block, EN-GJS-400-15U for the cylinder head and EN-GJL-200 for the liner. Tensile tests were carried out to obtain the ultimate tensile strength (UTS) of each material. The results for the UTS were: 460 MPa for EN-GJS-500-7U, 390 MPa for EN-GJS-400-15U and 170 MPa for EN-GJL-200. Likewise, Brinell-hardness measurements were carried out and the elements present in the materials were determined with spectrometry. Finally, the size of graphite particles in each sample was determined.

ISO 185/JL/350

Abstract ISO 185/JL/350 is a higher-tensile-strength gray cast iron that has a pearlitic matrix, and a tensile strength of 350–450 MPa (51–65 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. It provides a combination of high strength while still maintaining good thermal conductivity compared with other types of cast iron. This grade approaches the maximum tensile strength attainable in gray cast iron. Applications therefore tend to be confined to those where thermal conductivity requirements in service preclude the use of one of the other higher-strength materials such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on wear resistance as well as casting and heat treating. Filing Code: CI-85. Producer or source: International Organization for Standardization.

Povećanje otpornosti na trošenje elemenata brodskih dizelskih motora koji se izrađuju od nodularnog lijeva

This paper examines the influence of austempering and shot peening on the wear resistance of ductile iron. Samples for further testing were made from mechanically processed casts. The hardness and microstructure of ductile iron were examined on the prepared samples. Metallographic analysis of ductile cast iron samples in the cast state determined the pearlitic-ferritic structure of the matrix characteristic of this type of cast iron. Pearlite predominates in the structure, and the rest consists of ferrite and graphite nodules. The samples were then austempered. The isothermal conversion was 240 °C. After austempering, the hardness was measured and the microstructure was characterized, and the changes that occurred in relation to the heat-treated ductile iron were studied. Austempering created a new austempered structure, harder than that in the cast state, which led to improved mechanical properties. A needle-like structure of lower bainite (ADI) with high-carbon austenite, untransformed austenite, martensite and graphite nodules was achieved. The selected parameters of the shot peening process deformed the surface of the ADI and achieved a mostly martensitic structure without the presence of a soft phase, which increased resistance to abrasion. Additional hardening of the substrate by the shot peening process resulted in a composite material with the properties of comparative steel parts, which are lighter, cheaper and easier to manufacture, more resistant to wear and quieter in operation. Such material should have an even wider application in mechanical engineering, and thus in the construction of marine machinery and plants.

ISO 185/JL/300

Abstract ISO 185/JL/300 is a higher-tensile-strength gray cast iron that has a pearlitic matrix; it has a tensile strength of 300–400 MPa (44–58 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. It provides high strength while still maintaining good thermal conductivity compared with other types of cast iron. This grade approaches the maximum tensile strength attainable in gray cast iron. Applications therefore tend to be confined to those where thermal conductivity requirements in service preclude the use of one of the other higher-strength materials such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on casting and heat treating. Filing Code: CI-82. Producer or source: International Organization for Standardization.

Corrosion Resistance of Selected Cast Iron Grades Under Deposit Mining Conditions

The paper analyzes two types of alloyed cast iron used for pump impellers operated in mine working conditions. The research on corrosion resistance of two cast iron grades resistant to abrasive wear was presented. Tests were performed for chromium cast iron (HCCI) grade EN-GJN HV600 (XCr18) (acc. to EN 12513) and high-silicon cast iron HSCI Grade 1 (acc. to ASTM A 518/ A 518M - 99). Deposit mining is characterized by variable working conditions. Both types of cast iron are resistant to abrasive wear and are suitable for loaded elements (e.g. pump impellers). The paper presents a metallographic analysis of selected cast iron grades based on light microscopy. The chemical composition of the tested cast irons was determined with the Leco GDS 500 spectrometer; C and S content was determined with the CS125 Leco Carbon–Sulfur Determinator. The Si content for HSCI Grade 1 was determined by gravimetric method. Corrosion tests were performed under laboratory conditions. In-service tests of cast impellers were performed under real conditions (working mines applications). Corrosion resistance tests were measured with VoltaLab® Potentiostat (PGP 201). Performed tests resulted in the determination of the usefulness of materials used for dewatering pump impellers in mine working conditions. The results of laboratory tests were verified under the operating conditions of cast impellers. In the conditions of transporting a liquid-solid mixture at the moment of appearance of impurities (e.g. chlorine impurities) in the liquid, the impellers from cast iron HCCI revealed a tendency to pitting corrosion, which explains the exploitation results collected in the mining. After laboratory tests for sample from HCCI, the low value of breakdown potential Eb and repassivation Ecp was concluded which says about the absence of pitting corrosion resistance.