Composition Of Cast Iron Research Articles

Design Optimisation Of Spur Gear Using Genetic Algorithm

Gears are one of the most commonly used power transmission mechanisms in most types of machinery and. The design of gears is highly complicated involving the satisfaction of many constraints such as strength, pitting resistance, bending stress, scoring wear, and interference in involute gears. In addition, using conventional or traditional optimization techniques to solve this problem could not give optimum results. In this study, a spur gear pair was modelled and was subjected to static structural analyses for varying gear material. Stress analyses and deformation analyses were performed for each material and the optimum design for reduced weight structural stability was chosen. The design was then subjected to optimisation by Genetic Algorithm. A stochastic approach as a Genetic Algorithm (GA) is applied in this paper to find the optimal combination of design parameters for minimum weight of spur gears. The purpose of this study is minimizing the weight and the centre distance of one pair of spur gears. This objective was accomplished by the means of the GA under some constraint such as bending strength, a contact stress and each dimension conditions of gears, which must be satisfied. The results are calculated by using MATLAB tools of Genetic algorithm with three type of materials, which are alloy steel, cast iron, and epoxy glass composites.

Development Of A New Brand Of Alloy Instead Of 280x29nl Brand Spreadable Cast Alloy

This article a new brand 280X29NL (sample 1) alloy, which is economically inexpensive and corrosive, was developed without changing the chemical composition of high-chromium 280X29NL cast iron and reducing the mechanical properties of the alloy.

Effect of alloy powder on the properties of ZTA particles reinforced high chromium cast iron composites

Micrometer scale zirconia toughened alumina particles (ZTAp) reinforced high chromium cast iron (HCCI) matrix composites were prepared by the non-pressure infiltration casting process, which solved the poor compounding of micrometer scale ceramic particle preforms under seepage. The effects of the microstructure and the mechanical properties of ZTAp reinforced HCCI matrix composites by micro-powder contents in the preforms were systematically investigated. Alloy powder content of 65 wt.%, 55 wt.%, 45 wt.%, 35 wt.% and 25 wt.% was added to the composite material respectively. Phases of the composites was identified by optical microscope (OM), energy dispersive spectrometer (EDS) and x-ray diffraction (XRD). The best compressive properties of the composites were obtained when the content of alloy powder at 45 wt.%, which the strain reached 6.32% with a stress of 1229.63 ± 39.05 MPa. The fracture mechanism of the ZTAp reinforced HCCI composites mainly was brittle fracture and the ductile fracture was minor. This study shows that the addition of micrometer powder was contributed to improve the organization and properties of the ZTAp reinforced HCCI matrix composites. The reinforcement mechanism of composites not only depends on the load sharing of the reinforcing particles, the strength of the matrix was also critical.

Corrosion of cast iron sections of gas-collecting bells of EcoSoderberg electrolyser

The article presents results of the research of high-temperature gas corrosion of sections of EcoSoderberg electrolyzers’ gas-collecting bells (GSB) made of high-strength VCh50 cast iron with spherical graphite. The gravimetric method was used to study the specific mass losses of the sections due to corrosion. The microstructure of cast iron, structure, chemical and phase composition of corrosion products were studied using optical, electron microscopy and electron microprobe analysis. It was established that the specific weight loss of the sections during operation reaches 0.36 – 0.46 g/(cm2·month). Corrosion of cast iron sections of EcoSoderberg electrolyzers’ GSB is characterized by high unevenness by area. There are cases of decommissioning sections due to local through “burnouts” with a weight loss of 19 – 24 kg. With relatively uniform corrosion, the maximum allowable weight loss of the sections is 25 – 30 kg. To make predictive estimates based on experimental data, dependence of the sections’ mass loss on the operating time was obtained. It was found that the corrosion products of the sections consist of iron oxides and alloying elements of cast iron. Most samples are characterized by increased content of C, S, F, K, Al, and Na. Corrosion products have a pronounced layered structure and contain a large number of defects in the form of pores and cracks. The layers differ in chemical, phase composition, and macrostructure. All the studied samples are characterized by cyclic alternation of relatively dense layers of iron oxides Fe2O3 and Fe3O4 and more porous layers between them. The layers are characterized by increased content of C and F. Sulfur is evenly distributed over the thickness of corrosion products. The studied samples of corrosion products have high defectiveness, friability, large number of pores, cracks, discontinuities, and low adhesion to the surface of cast iron. This is due to the presence of phases and compounds with different coefficients of thermal expansion. The mechanism of corrosion products layers formation was established and scientifically proved.

Effect of High-Temperature Quenching on the Phase Composition, Structure, and Wear Resistance of Ni-Hard Chromium-Nickel Cast Iron

Metallographic, micro-X-ray spectral and X-ray structural analyses have been carried out. The quenching temperature increase from 900 to 1150 °C leads to high abrasive wear resistance in Ni-hard chromium-nickel cast iron. The initial hardness decreased before the test from 60 to 35 HRC due to the fact that the phase composition of the metal base before the wear test changes during quenching from medium-carbon martensite with secondary cementite to retained metastable austenite. It contributes to increase the crack resistance of cast iron. Austenite turns into dispersed friction martensite on the working surface in the process of wear testing or operation, as a result of the impact of abrasive particles. This martensite together with a part of cementite provides a high level of hardening and operability of the cast iron secondary microstructure.

Investigation of Brake disc using Metal Matrix Composites

The Brake disc is used to control the rotation of a wheel. Usually the brake disc made up of cast iron or ceramic composites. The current research is primarily deals with the modelling and analysing the disc brake using Pro-E and ANSYS. The brake-discs are designed using Pro-E and simulated using ANSYS which is based on the finite element method (FEM). The Structural & Thermal analysis is carry out in order to identify the firmness of the disc brake. In structural analysis displacement, ultimate stress limit for the design is found and in thermal analysis heat flow rates, and heat fluxes to be calculated by varying the two different materials of the disc. Differentiation can be concluded for displacement, stresses and nodal temperatures. Results will be compared for the two different material of the disc.

Influence of the chemical composition of cast iron on the tem-perature of loss of magnetic properties when heating by high-frequency currents

One of the important tasks of modern materials science concerning technical issues is the need to ensure the surface properties of hardened products. An increase in the resource of machines and an increase in reliability are limited by the wear resistance of their components and assemblies: the less wear of the main rubbing pairs, the longer the service life [1]. For example, according to [1], a piston internal combustion engine accounts for 36-52% of the total number of machine failures. Modern technologies have a large number of hardening methods that can increase almost any characteristic of the structural strength of the material. Surface hardening of parts can be carried out in two ways - by changing (modifying) the state of the surface layer or by coating.

Influence of alloying elements and heat treatment on the mechanical properties of chromium cast iron

The results of experimental studies to determine the effect of alloying and heat treatment on the mechanical properties of the high-chromium cast iron are described. When alloying the melt with nickel, molybdenum and manganese, as well as during heat treatment by quenching, specific wear, tensile strength in bending of the obtained samples, their hardness and microhardness were studied. A comparative analysis of the influence of alloying elements and heat treatment methods has been performed. When alloying Ni, Mo, and Mn, cast specimens that have not undergone heat treatment have the highest specific wear. It was established that the hardened Ni alloyed samples have the greatest bending strength. It was found that cast samples that were not subjected to heat treatment have much lower hardness and microhardness. The approximate composition of chromium cast iron was determined for further studies to increase its wear resistance. The research results are used in the manufacturing process of parts for crushing and grinding equipment.

Application of Machine Learning in the Control of Metal Melting Production Process

This paper presents the application of machine learning in the control of the metal melting process. Metal melting is a dynamic production process characterized by nonlinear relations between process parameters. In this particular case, the subject of research is the production of white cast iron. Two supervised machine learning algorithms have been applied: the neural network and the support vector regression. The goal of their application is the prediction of the amount of alloying additives in order to obtain the desired chemical composition of white cast iron. The neural network model provided better results than the support vector regression model in the training and testing phases, which qualifies it to be used in the control of the white cast iron production.

RESEARCH OF THE INFLUENCE OF SLOW-DOWN COOLING SPEED IN THE INTERVAL OF EUTEKTIC TRANSFORMATION ON THE STRUCTURE AND MECHANICAL PROPERTIES OF CAST IRON CASTINGS

The work is devoted to the study of the effect of slowing down the cooling rate in the interval of eutectic transformation on the structure and mechanical properties of castings from gray doeutectic iron. To slow down the cooling rate in the interval of eutectic transformation, an exothermic carbon-containing additive, fuel oil M-100, was used. It is shown that the use of controlled cooling can significantly increase the quality index of cast iron without introducing additional alloying elements into the composition of cast iron.

The Importance of SiC in the Process of Melting Ductile Iron with a Variable Content of Charge Materials.

The article presents issues related to melting ductile iron grade EN-GJS-400-15, with different proportions of feedstock (steel scrap and pig iron). The main attention was paid to determining the impact of silicon carbide on the structure and properties of melted cast iron. In the conducted melts, carbon and silicon deficiencies were supplemented with a suitably chosen carburizer, ferrosilicon, and SiC metallurgical silicon carbide. The percentage of silicon carbide in the charge ranged from 0 to 0.91%. The basic condition for the planning of melts was to maintain the repeatability of the chemical composition of the output cast iron and cast iron after the secondary treatment of liquid metal with various charge compositions. Based on the tests, calculations, and analyses of the results obtained, it was concluded that the addition of SiC may increase the number and size of graphite precipitates. Increasing the SiC content in the charge also caused a change in the solidification nature of the alloy and the mechanism of growth of spheroidal graphite precipitates, causing their surface to form a scaly shell. The influence of the addition of silicon carbide on the reduction of the temperature of liquidus in the alloys was also observed. Silicon carbide had a positive effect on the structure and properties of melted alloys. The introduction of SiC into the melting in the studied range caused an increase in the content of carbon and silicon without causing an increase in the amount of impurities in the alloy.

Microstructural Characterization of TiC-White Cast-Iron Composites Fabricated by In Situ Technique.

High-chromium white cast-iron specimens locally reinforced with TiC–metal matrix composites were successfully produced via an in situ technique based on combustion synthesis. Powder mixtures of Ti, Al, and graphite were prepared and compressed to fabricate green powder compacts that were inserted into the mold cavity before the casting. The heat of the molten iron causes the ignition of the combustion reaction of the reactant powders, resulting in the formation of the TiC by self-propagating high-temperature synthesis. The microstructure of the resultant composites and the bonding interfaces was characterized by scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The microstructural results showed a good adhesion of the composite, suggesting an effective infiltration of the metal into the inserted compact, yet a non-homogeneous distribution of the TiC in the martensite matrix was observed. Based on the results, the in situ synthesis appears to be a great potential technique for industrial applications.

Study of the effect of differentiated cooling modes on the structure and mechanical properties of gray cast iron

The effect of the differential cooling regime on the structure and mechanical properties of gray iron castings is investigated. A technical solution has been developed for the differentiated change in the cooling rate of cast iron castings. An increase in the cooling rate during dendritic crystallization was achieved by blowing the mold with compressed air. To slow down the cooling rate in the interval of eutectic transformation, an exothermic carbon-containing additive, fuel oil M-100, was used. It is shown that the use of controlled cooling can significantly increase the tensile strength of cast iron without introducing additional alloying elements into the composition of cast iron.

ІНФОРМАЦІЙНО-МАТЕМАТИЧНЕ ЗАБЕЗПЕЧЕННЯ ТЕХНОЛОГІЇ ДЕСУЛЬФУРАЦІЇ ЧАВУНУ

The concept of the expert decision-making system for technological process management, created earlier at the Iron and Steel Institute of the National Academy of Sciences of Ukraine, provides for the choice of a rational technology for out-of-furnace desulfurization of cast iron. The purpose of this work is the further development of information and mathematical support of the expert system module for out-of-furnace processing of cast iron by co-injection of magnesium and lime in the framework of the target project to create end-to-end technology for high quality metal products. An integrated database of cast iron desulfurization process of a number of metallurgical enterprises of the People's Republic of China and the domestic DMK plant is presented. Based on the analysis of technological data, empirical equations were obtained to determine the final sulfur content in the cast iron melt, as well as the expression for estimating the specific consumption of metallic magnesium in the reagent. The developed models for calculating the specific consumption of reagents are the basis of the algorithm for calculating the indicators of the process of desulfurization of cast iron with co-injection of magnesium and lime. The input parameters are: temperature of cast iron, mass of cast iron, chemical composition of cast iron and slag, sulfur content initial and final, the proportion of magnesium in the reagent. Replenishment of the database with information on the technology of desulfurization of cast iron with a mixture of magnesium and lime allowed to clarify the existing and obtain descriptive models for these reagents. The developed information and mathematical support of the subsystem of out-of-furnace processing of pig-iron takes into account material and energy costs for redistribution, providing resource savings and the required quality of metal products.

The durability of parts of internal combustion engines under thermal stress loading

The paper analyzes the structural material-cast iron for diesel engines, from which the cylinder head covers are made. The main defect of these complex metal-intensive parts are heat-resistant cracks. The analysis of chemical composition of cast irons of various manufacturers is made. As a result of the conducted researches chemical compositions of the pig-irons having the greatest heat-fatigue durability are defined. It is established that to increase their strength and durability in operation, it is necessary to change the percentage of basic chemical elements (C, Si, Mn) in cast iron to use rare earth metals (Y, Ce, La). Specific recommendations are given on the choice of the chemical composition of cast iron for cylinder heads and covers, providing an increase in their fatigue strength and durability during operation. The best combination of mechanical and thermal fatigue strength was shown by samples containing carbon C-4.0%, silicon Si-2.0%, manganese Mn-0.18%, yttrium Y-0.1%, and copper Cu-0.8% with sulfur s – 0.008% and phosphorus P – 0.1%.

Design and Analysis of Disc Brake using ANSYS

Braking is a procedure that changes over the kinetic vitality of a vehicle into mechanical vitality, which must dissipate heat. A brake plate generally made of cast iron or clay composites is connected to the wheel. The friction material of brakes (i.e) brake cushions is upheld precisely by using pressurized water, pneumatically or electromagnetically to the two sides of the plate which holds the wheel. The present examination basically manages the modeling and breaking down a ventilated circle brake by Solid works and ANSYS. FE models of the brake are molded with solid works and reproduced by utilizing ANSYS which depends on the finite element technique (FEM). This thermal investigation is done as such as to get the quality of the brake. The suitable design is found and heat flow rates and heat fluxes in the thermal examination, are considered by fluctuating the cross segments and materials of the disc brake rotor.

Comparison of properties and impact abrasive wear performance of ZrO2-Al2O3/Fe composite prepared by pressure casting and infiltration casting process

Abstract A ZrO2-toughened Al2O3 (ZTA) particle-reinforced high chromium cast iron (HCCI) composite was prepared by pressure bonding following flow mixing (PB-FM). Its microstructure, mechanical properties, and impact abrasive wear behavior were investigated and compared with a similar commercially available composite (Xwin® composite), which is prepared by infiltration casting. The PB-FM composite exhibited better wear performances under high impact energies. The wear mechanisms of the investigated composites at low impact energies were mainly ploughing and cutting of the matrix and slight breaking of the reinforcements, whereas at high impact energies, they were dominated by the breaking and detachment of the reinforced particles, embedded abrasives, and spalling pits.

IMPROVING THE MECHANICAL PROPERTIES OF THE IRON PARTS OF ICE BY THE METHOD OF COMPLEX DOPING

The article presents the results of long-term studies on the preparation of ligatures for gray and high-strength cast iron, which are used for the casting of key parts of internal combustion engines (ICEs). The main purpose of the study is to extend the life of the components of the ICE by increasing the wear resistance of the main parts (cylinder liners and piston rings). The objectives of the study are to develop a ligature and technology for gray and high-strength pig-iron. The research methods included mathematical modeling by means of regression analysis of Gram matrices formed on the basis of the determined correlation coefficients between the wear resistance of cast iron and its chemical composition, which was checked by Fischer's criterion, as well as practical studies on the casting of pig iron of various brands and bench tests of engines with parts on their basis. The regression equation describing the optimal chemical composition of cast iron is given as I = 8.4 +0.9C- 0.6Si - 3.2Mn - 84.4P - 4.5Ti - 33.8S + 9.3Cr + 0.4Ni - 5 , 9Cu - 1,1V + 24,3Mo. The basis for the development was the analysis of a sufficient number of literary sources related to the dopant properties of different elements when applied in gray and high-strength pig-iron. The main results of the literary search are presented in the corresponding section, where doping with nickel, chromium, molybdenum, vanadium, copper, silicon, titanium and other elements is covered. It was developed and protected by patents of Ukraine No. 25099 and number 25100 highly effective ligatures for pig-iron parts of cylinder-piston group (CPG). The bench tests of hardness resistance of the received pig-iron showed that the formation of sorbitol perlite due to alloying of pig iron in the ladle is an optimal approach that in combination with other measures can significantly improve the quality of the obtained parts. Thus, studies have shown that for super-loaded parts of the cylinder-piston group, the inevitable transition to doped pig-iron is inevitable. For pig-iron for bushings of cylinders of diesel engines of type ЧН 25/34 it is connected with their transition to high-grade fuel, and the work of new forced engines 6CHN 26/34 without doped pig-iron was not possible.

INVESTIGATION ON TRIBOLOGICAL BEHAVIOR OF DUCTILE CAST IRONS WITH NANOSIZED PARTICLES

The work in this study is focused on investigation of the tribological behavior of ductile cast iron with nanosized particles: titanium nitride TiN; titanium nitride 30% + titanium carbonitride 70% (30%TiN+70%TiCN). The ductile cast iron composition is: Fe-3,55C-2,67Si-0,31Mn-0,009S-0,027P-0,040Cu-0,025Cr-0,08Ni-0,06Mg wt%. Before the addition to the melt nanosized particles were coated with nickel by the electroless nickel deposition method EFFTOMNICKEL .The nickel coating on the nanosized particles ensures their wetting in the melt as well as their uniform distribution into the cast. The optical and quantity metallographic observations and wear test are performed to study the influence of the nanoparticle additives on the cast iron tribological properties. It is observed that the quantity proportion changes between pearlite, ferrite and graphite phase in the cast iron structure. The graphite shape is retained the same, but the nanosized additives decrease the average diameter of the graphite spheres Dmid and increase the quantity of the graphite phase in the structure of ductile cast irons. The cast iron wear resistance in the presence of nanosized additives of (TiN+TiCN) and TiN increases to 55–69% in comparison to wear resistance of the cast iron without nanoparticles.

Effect of Quartzite Heat Treatment on Induction Furnace Lining Failure Mechanism

The wear mechanism of a quartzite lining of induction crucible furnaces during iron and steel smelting is presented. It is established that the main cause of lining wear is a decrease in its strength due to transition of the tridymite joints into cristobalite, which is more readily washed off crucible walls by moving metal and slag. The second important factor of wear is the choice of quartzite raw material, its substance and grain size compositions, firing regime, and melting technology during furnace operation. Silicon reduction from silica of the carburizer lining and within the cast iron composition is a subsidiary factor of crucible lining wear.