Gray Iron Research Articles

Brake Power and Load Analysis of Electromagnetic Braking System

This study aimed to develop a model and prototype of a more sustainable electromagnetic braking system which can cope with the future demands of the automobile industry due to the increasing number of e-vehicles. The braking mechanism is been used in almost every type of mechanical vehicle and it utilizes crude oil as fuel which when burnt causes air pollution. To save the environment from air pollution e-vehicles have been introduced to the market. Electromagnetic brakes are been used in e-vehicles as these vehicles incorporate huge electric systems which may be damaged or ignited through any leakage from the hydraulic brake. In this study, engineering knowledge has been implemented to design and fabricate a model of the electromagnetic braking system (EMS) which works on the principle of eddy current. A 3D model of EMS was developed. Further, static displacement and brake power analyses were performed to check the strength of EMS and the performance of the prototype developed, respectively. At an average speed of 31 RPM, brake power produced was 3.9 W. Static structural analysis on a frame made of grey cast iron showed that there was negligible deformation for load up to 200 N. Electromagnetic braking system based on this analysis and model could meet the market needs for conveyor belt application as well. The observations from this study might be useful in the development of a more efficient electrical vehicle braking system with varying demands of momentum.

Procedure of Eliminating Porosity in Grey Cast Iron with Low Sulphur Content.

This study shows that the inoculation process of a molten alloy is crucial in disposing of porosity-type defects. A thermal analysis is used to assess the physico-chemical state of a molten alloy, which can be an indicator of the inoculation effect. A modern thermal analysis should be able to perform a quick data-analysis and provide information about any possible problems in a casting if it is poured with the analysed alloy. The time of the transmission of this information depends on whether we can make a decision and introduce changes to the metallurgical process. An important piece of information that can be obtained in this way is a message about the possibility of the appearance of porosity in a cast iron casting. In such a situation, an operator can react by applying an additional dose of inoculant. The porosity that is indicated by the thermal analysis systems can be either gaseous or shrinkage in nature. The research that is presented in this paper is based on two industrial castings that are made of cast iron with reduced sulphur content, in which shrinkage porosity occurred and was detected during the mechanical machining of the castings. As a result of laboratory tests in which iron powder was introduced along with an inoculant, a mixture was developed that, when applied under industrial conditions, eliminated the porosity defects by increasing the number of austenite dendrites. The ITACA thermal analysis system was used at each stage of the research, which allowed for the faster and more precise determination of the appropriate amount of the inoculant mixture that was used.

Characterization of deposit layers formed on grey cast iron

This paper presents the results of diagnostic examinations conducted on the water pipe made of grey cast iron that were operated in conditions for 260 thousand hours. The tube was exposed in a soil. The phase composition of the deposit layers formed on both sides of the tube walls (outside and inside) was examined using optical and confocal microscopy and X-ray diffraction. The obtained XRD test results showed that mainly -FeOOH) and γ-FeOOH is formed on the inside of the pipe wall. In turn, on the outside, in addition to the above-mentioned compounds, also SiO2 is formed. The results of these examinations have shown a higher degradation of pipe on the outer side. The arithmetic mean deviation of the profile from the mean line was 6.23 µm and 8.07 µm for the inner and outer side of the pipe wall, respectively. The work demonstrates the usefulness of material science, especially X-ray structure, topography and surface studies, in characterizing the degradation processes of layers formed on gray cast iron exploited in the water supply industry.

Increasing wear resistance of the protective bush-ing of the centrifugal pump made of gray cast iron by chemical-thermal treatment

Problem. The weak link that reduces the warranty time of centrifugal pumps is a unit that includes protective bushings and seals. The purpose of the bushings is to protect the rotor shaft from erosion, corrosion and wear. The bushing works under conditions of abrasive wear by elements of the seal packing and abrasive particles entering the liquid pumped by the pump. Due to accelerated surface wear, cast iron protective bushings do not satisfy the requirements service life. Goal. The purpose of the work is to increase wear resistance of pump parts made of gray cast iron by chemical and thermal treatment. Method. Metallographic studies of the structure were performed under a UIT MicroMet-D-101 microscope. Wear is studied using the roller-pad method on a friction machine. Sulfocyanation of cast iron samples was carried out in molten salts (K2CO3, CO(NH2)2, Na2S at 560°С at the bottom of the bath. Results. In the cast state, the microstructure of gray cast iron consists of ferrite, pearlite, double phosphide eutectic and lamellar graphite inclusions. The influence of exposure time during sulfocyanation in a bath with molten salts on the structure and properties of the formed surface layer was studied. The exposure was carried out for 2 hours, 3 hours 30 minutes and 6 hours. After exposure in the bath, a thin carbonitride layer is formed on the surface of the cast iron, and a layer consisting of iron sulfide is formed on top. Conducting wear tests showed that sulfocyanation increases the wear resistance of gray cast iron. An increase in the wear resistance of cast iron is provided by a hard carbonitride layer, and good workability – by a layer of iron sulfides, which acts as a lubricant. Scientific novelty. Increasing the exposure time during sulfocyanation in the bath for more than 3 hours 30 minutes does not affect the thickness of the carbonitride layer. Practical significance. As an optimal mode of sulfocyanation, exposure for 3 hours 30 minutes can be recommended, which provides a 4.8-fold increase in wear resistance.

Study on the application of a granite composite material in five-axis CNC-VMC machine Tool

A five-axis CNC-VMC machine tool generally has a high-speed spindle spinning at a maximum rotation of 50,000 rpm, under which the machine tool bed will violently vibrate that leads to poor machining precision and surface quality of workpiece. The gray cast iron, as the typical material of a machine tool, exhibits poor dynamic suppression of vibration that its processing yield and quality can no longer satisfy the product demand of current market. Consequently, in this study, we proposed granite composite material (GCM) in place of gray cast iron for the structure of machine tool, which would be mixed with main ingredients of high-strength epoxy resin and cemented carbon fibers and fillers to maximize the structural properties of the machine tool. The sample of granite composite material would first be tested for its mechanical properties. The results showed that the GCM cast with only 1/3 density of gray cast iron could withstand a maximum compressive stress of 125.8 MPa. With this granite composite material used in a digitally controlled machine tool bed, the maximum stress and the maximum strain exerted on the machine tool were reduced by 68.93% and 72.6%, respectively, when compared with the cast iron, while the 1st to the 6th-order natural frequencies of the machine tool of mineral composite was significantly increased by 20% to 30%, giving it more resistance to vibration than the gray cast iron. The stability and precision of the machine tool were shown to have been drastically improved by using the granite composite material.

JSA FC300

Abstract JSA FC300 is a higher-tensile-strength gray cast iron that has a pearlitic matrix, and a minimum tensile strength of 300 MPa (44 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. The tensile strength of JSA FC300 approaches the maximum tensile strength attainable in gray cast iron. It provides a combination of high strength while still maintaining good thermal conductivity. 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, hardness, and tensile properties. It also includes information on casting and heat treating. Filing Code: CI-97. Producer or source: Japanese Standards Association (JSA).

Effect of V and Sn on microstructure and mechanical properties of gray cast iron

The cylinder liner is one of the important parts of a diesel engine. Gray cast iron is the main material for manufacturing cylinder liners due to its good casting performance, convenient processing performance, good wear resistance and low cost. In the present work, the effects of vanadium (V) and tin (Sn) on the microstructure and properties of gray cast iron were studied. Results show that increasing the contents of V and Sn can not only refine the graphite, but also reduce the pearlite lamellar space. The graphite size and lamellar spacing of pearlite are firstly reduced and then increased. Pearlite quantity reaches over 98% after adding V and Sn. Adding V and Sn can promote the precipitation and solid solution strengthening of gray cast iron, so as to improve the mechanical properties. The Brinell hardness reaches the peak of 424 HB at the contents of 0.21wt.% V and 0.06wt.% Sn, and the sample containing 0.11wt.% V and 0.08wt.% Sn shows the highest compressive strength and tensile strength of 1,699 MPa and 515 MPa, respectively. The main strengthening mechanism comes from the solid solution strengthening and fine grain strengthening of V and Sn.

ACO EUROBAR EN-GJL-250C (5.1203)

Abstract ACO Eurobar EN-GJL-250C (5.1203) is an intermediate-tensile-strength gray cast iron that is produced by the continuous casting process. Compared with the lower strength gray cast iron grade, EN-GJL-200C (5.1202), it possesses superior wear resistance, while still maintaining good thermal conductivity, damping capacity, and machinability. Brinell hardness values in Table 3 corrected September 2022. This datasheet provides information on composition, physical properties, microstructure, hardness, and tensile properties. It also includes information on heat treating and machining. Filing Code: CI-94. Producer or source: ACO Eurobar GmbH (a subsidiary of ACO Guss GmbH).

Rinser Machine and the Dynamics-based Failure Analysis for Spur Gear Fault Detection: A Forensic Review

Gear fault detection and its severity is essential for analyzing the availability, maintainability and reliability of rinser machines. The occurrence of multiple failures of gears and their analysis is becoming more challenging, thereby causing the increased unavailability of rinser machines. This study reviewed the rinser machine and its various advantages and disadvantages, including the problems associated with the machine. More so, various types of failures associated with the spur gears were studied, and it was established that the detection and the diagnosis of gear faults would inform a maintenance planner on scheduled maintenance. Thus, the absence of failure detection will cause uncontrolled machine breakdown and, consequently, result in unsafe operation as well as a loss of productivity. The study concludes and recommends grey cast iron as alternative material that could reduce chemical failure and failure resulting from fatigue.

Modulation-assisted machining of compacted graphite iron with coated carbide tool in dry condition

Compacted graphite iron (CGI) is a new material replacing conventional gray cast iron (FGI) for diesel engine block applications due to its superior mechanical properties. However, widespread adoption of CGI is hindered by its poor machinability, which is reflected by the rapid tool wear especially at higher cutting speeds. In current industrial practice, CGI is usually machined with coated carbide tools at low to medium speeds (< 200 m/min). This study investigates the effect of modulation-assisted machining (MAM) on tool wear in dry turning of CGI with coated carbide tool. A new MAM turning setup is implemented for conducting the longitudinal turning experiments. Tool wear, cutting forces and tool temperature are characterized for both conventional machining (CM) turning and MAM turning at three cutting speeds: 150, 250 and 350 m/min. The results show wear reduction by MAM is not significant at the low cutting speed (150 m/min), but it is quite significant at the higher cutting speeds (250 and 350 m/min). The cutting force and temperature results can be well correlated with the wear results, revealing the dependency of the forces and temperature on the tool wear and the severity of iron adhesion. This study demonstrates the potential of MAM in enhancing the productivity of machining CGI with the coated carbide tool. The results are also useful for better understanding the wear mechanism in cutting CGI with the coated carbide tool.

Computer Simulation of the Solidification of a Standard Gray Cast Iron Sample

Computer Simulation of the Solidification of a Standard Gray Cast Iron Sample

Sliding movement temperature analysis between composite conductor rail and a collector shoe

Electrical traction systems come in different forms, depending on the railway and terrain. The collector shoe is a critical component that impacts the train’s overall safety. The majority of collector shoes consist of several types of gray cast iron that are highly resistant to sliding wear. Wear is produced by friction and electrical current at temperatures over the melting point, which results in decreased sliding speeds. Applying an electric current to a sliding contact alters the process temperature of the wear without changing the sliding speed. The study is essential for industrial applications, especially in subway transit. This study aims to learn more about the wear characteristics of a composite aluminum–stainless steel conductor rail moving across a current collector. The authors employed a finite element analysis and a series of electric current testing. This research will produce some intriguing test findings. Based on a friction pair consisting of a composite conductor rail of aluminum and stainless steel and gray cast iron, a sliding friction contact model was built in the COMSOL finite element software. When the findings of the finite element analysis and the pin-on-plate test technique are compared, the maximum temperature variance is 10%, while the minimum temperature variation is 0.8%. Additionally, the results reveal that acclimation and rupture occur more rapidly when speed rises, and a steady temperature rise may be achieved more quickly.

Improving Sustainability Index of Grey Cast Iron Finish Cutting Through High-Speed Dry Turning and Cutting Parameters Optimization Using Taguchi-Based Bayesian Method

Improving Sustainability Index of Grey Cast Iron Finish Cutting Through High-Speed Dry Turning and Cutting Parameters Optimization Using Taguchi-Based Bayesian Method

Experimental Investigation on the Machinability of PCBN Chamfered Tool in Dry Turning of Gray Cast Iron

Polycrystalline cubic boron nitride (PCBN) tools are widely used for hard machining of various ferrous materials. The edge structure of the PCBN cutting tool greatly affects the machining performance. In this paper, dry turning experiments were conducted on gray cast iron with a PCBN chamfered tool. Both the cutting temperature and the cutting force were measured, and then the surface quality and tool wear mechanisms were analyzed in detail. It was found that the cutting temperature and cutting force increased with the increase in feed rate, depth of cut, and cutting speed. The surface roughness firstly decreased, and then increased with an increase in feed rate. The minimum surface roughness was obtained with a feed rate of 0.15 mm/r which exceeded the tool chamfer width. The PCBN tool wear mode was mainly micro notches on the rake face and micro chipping on the tool chamfer, while the adhesion wear mechanism was the main tool wear mechanism.

CEN EN-GJL-200 (5.1300)

Abstract CEN EN-GJL-200 is an intermediate-tensile-strength gray cast iron that has a predominantly pearlitic matrix, and a tensile strength of 200–300 MPa (29–44 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. Compared with the lower strength gray cast iron grades, CEN EN-GJL-200 contains lower carbon and silicon contents and exhibits superior wear properties, while still maintaining good thermal conductivity, good damping capacity, and good machinability. This datasheet provides information on composition, physical properties, tensile properties, and bend strength. It also includes information on casting, heat treating, and machining. Filing Code: CI-96. Producer or source: European Committee for Standardization (CEN).

Study on the effect of alloying elements Ni, Al, and Si on salt spray corrosion resistance of gray cast iron

AbstractIn this paper, the effect of elements such as Ni, Al, and Si in gray cast iron on the atmospheric corrosion resistance of gray cast iron was studied by using corrosion weight gain, salt spray test, electrochemistry, and X‐ray diffraction. The results show that the corrosion behavior of gray cast iron can be divided into two stages. The later stage of corrosion resistance of gray cast iron with Ni element is better than the early stage of corrosion resistance, while the reverse is true for gray cast iron with Al element. There is no significant effect of increasing the Si content on the corrosion behavior of gray cast iron. The corrosion products of each specimen are all composed of Fe2O3, α‐FeOOH, γ‐FeOOH, and Fe3O4. After the comparison test, it can be concluded that the Ni element is seen to be conducive to the formation of protective rust layer with higher α‐FeOOH content. In addition, the rust layer of gray cast iron containing Al is loose and scaly, while the rust layer of gray cast iron containing Ni is dense and spongy. The addition of Ni element can make gray cast iron stable to improve the self‐corrosion potential and reduce the self‐corrosion current density, thus reducing the corrosion rate of gray cast iron.

A two-scale model of degenerated graphite in cast iron

A two-scale model for clusters of degenerated graphite in gray cast iron is presented. The novelty of the model is that, at the mesoscale, a single cluster is described as a spheroidal inclusion made of porous materials. At the microscale, the porous material contains a random distribution of randomly oriented spheroidal voids modeling the graphite precipitates. To calculate the stress state inside and at the outer surface of the cluster, two different approaches are presented. In the first approach, the effective elastic properties of the porous material at the microscale are obtained using Pan and Weng homogenization scheme, based on Eshelby’s equivalent principle and the Mori-Tanaka’s estimate; at the mesoscale, the stress distributions inside and at the outer surface of the cluster are calculated using Eshelby’s solution applied to an inclusion made of equivalent porous material. The second approach is based on a finite element analysis of a cluster embedding 216 randomly oriented and randomly distributed spheroidal voids. A comparison between the numerical results obtained with the two approaches indicates good agreement in terms of average (elastic and stress distribution) properties. The equivalent elastic properties (Young’s modulus) calculated at the microscale in the two approaches are also compared with some experimental results available in the scientific literature.

Tailoring the Hybrid Magnetron Sputtering Process (HiPIMS and dcMS) to Manufacture Ceramic Multilayers: Powering Conditions, Target Materials, and Base Layers.

The mechanical and wear behavior of CrN/CrAlN multilayers were improved by tailoring the experimental conditions of a hybrid magnetron sputtering process based on a high-power impulse (HiPIMS) and two direct current magnetron sputtering (dcMS) power supplies. To this end, the influence of the base layer and of the combination of Cr and CrAl targets, which were switched to the dcMS and HiPIMS power supplies in different configurations, were investigated with respect to the growth of ceramic CrN/CrAlN multilayers onto commercial gas-nitrided diesel piston rings. The microstructure, grain morphology, and mechanical properties were evaluated by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and instrumented nanoindentation. Bench wear tests simulating the operation of a combustion engine were conducted against a gray cast iron cylinder liner under reciprocating conditions using 0W20 oil as a lubricating agent enriched with Al2O3 particles. The results revealed a significant increase in hardness, resistance to plastic strain, and wear resistance when two CrAl targets were switched to a HiPIMS and a dcMS power supply, and a Cr target was powered by another dcMS power supply. The compressive coating stresses were slightly reduced due to the soft Cr base layer that enabled stress relief within the multilayer. The proposed concept of hybrid magnetron sputtering outperformed the commercial PVD coatings of CrN for diesel piston rings manufactured by cathodic arc evaporation.

Laser Surface Hardening of Graphite Cast Iron

Two types of graphite cast iron are evaluated. The effect of laser surface hardening is compared using metallographic analysis of the microstructure and measurement of hardness profile. Conditions of the hardening were the same for both analyzed materials. The alloys that were compared are: cast iron with lamellar graphite EN GJL-200 and cast iron with nodular graphite EN GJS-700 CuNi. Microstructure of tested cast irons was pearlitic-ferritic. Laser surface heat treatment caused formation of martensitic layer. The depth and structural compositions of hardened layers do differ. In the case of gray cast iron the higher hardened depth was achieved and in the case of ductile cast iron the higher hardness was observed.

Correction to: Gray Iron Aging Effects as Measured Using NDT and Microstructural Analysis

Correction to: Gray Iron Aging Effects as Measured Using NDT and Microstructural Analysis