Gray Iron Research Articles

Numerical characterisation of the rotational behaviour of grey cast iron tunnel joints

The structural assessment of segmental grey cast iron (GCI) tunnel linings to nearby construction is challenging due to the presence of the joints affecting the stiffness of the tunnel lining. This paper presents an extensive investigation, using 3D finite element (FE) analyses, into the bending moment-rotation (M-θ) behaviour of two GCI tunnel joint geometries. These two geometries correspond to standard running and station tunnels of the London Underground network. The contribution of this study is two-fold. i) The novel characterisation of the M-θ response enables the development of new models for simulating the mechanical response of GCI tunnel joints with structural elements which can be used in simplified, 2D geotechnical analysis for tunnel safety assessments. ii) The analyses provide insight into the behaviour of GCI tunnel linings that would be difficult to achieve through experimental and field observations alone. More specifically, the analyses show that when the bolts are removed from the joints the possibility of tensile failure can be disregarded; that the initial bolt preload influences the rotational stiffness only after some rotation has taken place and does not alter the bending moment of opening; and that the out-of-plane displacement restraint has little influence on the joint response.

Anticorrosion and Antibacterial Properties of Al NP–Epoxy Nanocomposite Coating on Grey Cast Iron

In this study, different concentrations of aluminium nanoparticles (Al NP) were incorporated into epoxy resin and epoxy paint. Here, we present a detailed systematic study of different methods of incorporating inorganic nanoparticles into epoxy coating. This work aims to obtain an epoxy coating with anticorrosion and antibacterial properties. The physical properties of coatings such as thickness, hardness, colour, and adhesion did not change with the addition of nanoparticles. According to the SEM and EDS analyses, the distribution effect of Al NPs in epoxy coating was better with ultrasonic homogenisation than with mechanical stirring. The EIS and SECM measurements were used to investigate corrosion resistance. The coating with 1.0 wt.% Al NP showed the best physical and chemical properties. SECM examination indicated that nanoparticles in epoxy resin increase the protection efficiency by 25.75% and in the epoxy paint by 40.89%. The results also showed the antibacterial activity of aluminium nanoparticles by inhibiting the growth of biofilm-forming bacteria such as P. aeruginosa and B. subtilis.

ISO1083/JS/400-15

Abstract ISO1083/JS/400-15 is a ferritic spheroidal graphite cast iron that has a minimum tensile strength of 400 MPa (58 ksi) and a minimum elongation of 15%, when measured on test pieces machined from separately cast samples. It has a tensile strength exceeding that of the highest-tensile-strength grade of gray cast iron, together with much higher elongation and impact resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on casting and heat treating. Filing Code: CI-105. Producer or source: International Organization for Standardization.

Improving technology for manufacturing casting case of truck clutch release cylinder

The object of research: Manufacturing technology of body castings for trucks using the example of a clutch release cylinder body made of gray cast iron with flake graphite EN-GJL-200.
 Investigated problem: Finding ways to reduce the weight and size characteristics of cast parts.
 The main scientific results: A mathematical model has been developed that has made it possible to determine the optimal compositions of alloying Cr/Ni – Cu/Ti complexes that ensure an increase in the grade of cast iron by increasing the tensile strength at elevated carbon contents. This makes it possible in the future to reduce the thickness of the walls of the castings, achieving a reduction in their weight and size characteristics
 The area of practical use of the results of the study: Automotive industry in terms of technology for manufacturing cast parts for trucks
 Innovative technological product: Improved technology for manufacturing the clutch release cylinder body due to optimization of melt technology and out-of-furnace processing allows for targeted selection of melt processing modes, ensuring an increase in the strength characteristics of cast iron for cast body parts, thereby moving from the EN-GJL-200 cast iron grade to the EN grade -GJL-250 and EN-GJL-300.
 The scope of the innovative technological product: Foundries of engineering enterprises, in particular those producing trucks, in which iron castings are produced

Behavior of a 2.66%C-17.9%Ni gray cast iron with an austenitic matrix under simulated marine corrosion.

Behavior of a 2.66%C-17.9%Ni gray cast iron with an austenitic matrix under simulated marine corrosion.

Early succession of biofilm bacterial communities in newly built drinking water pipelines via multi-area analysis

Biofilms inhabiting pipeline walls are critical to drinking water quality and safety. With massive pipeline replacement underway, however, biofilm formation process in newly built pipes and its effects on water quality are unclear. Moreover, differences and connections between biofilms in newly built and old pipes are unknown. In this study, early succession (≤ 120days) of biofilm bacterial communities (abundance and diversity) in upper, middle and bottom areas of a newly built cement-lined ductile iron pipeline were evaluated using improved Propella™ biofilm reactor and multi-area analysis. A comparison with old pipelines (grey cast iron, 10years) was performed. In the newly built pipeline, the abundance of biofilm bacteria did not change significantly between 40 and 80days, but increased significantly between 80 and 120days. The biofilm bacterial abundance (per unit area) in the bottom area was always higher than that in the upper and middle areas. Based on alpha diversity index and PCoA results, biofilm bacterial community richness, diversity and composition did not change significantly during the 120-day operation. Besides, biofilm shedding from the walls of newly built pipeline significantly increased bacterial abundance in the outlet water. Opportunistic pathogen-containing genera, such as Burkholderia, Acinetobacter and Legionella, were identified in both water and biofilm samples from newly built pipelines. The comparison between new and old pipelines suggested a higher bacterial abundance per unit area at the middle and bottom areas in old pipelines. Moreover, the bacterial community composition of biofilms in old pipelines was similar to that of newly built pipelines. These results contribute to accurate prediction and management of biofilm microbial communities in drinking water pipelines, ensuring the biosafety of drinking water. KEY POINTS: • Biofilm bacterial communities in different areas of pipe wall were revealed. • The abundance of biofilm bacteria increased significantly between 80 and 120days. • Biofilm bacterial community compositions of newly built and old pipes were similar.

Evaluation of the Number of Primary Grains in Hypoeutectic Chromium Cast Iron with Different Wall Thickness Using the ProCAST Program.

The treatment of inoculation of white cast iron with carbide precipitations that consist of increasing the number of primary austenite grains is not as well-known as the treatment of inoculation of gray cast iron in which the number of eutectic grains increases. In the studies included in the publication, experiments were carried out using the addition of ferrotitanium as an inoculant for chromium cast iron. The Cellular Automaton Finite Elements (CAFE) module of ProCAST software was used in order to analyze the formation of the primary structure of hypoeutectic chromium cast iron in a casting of various thicknesses. The modeling results were verified using Electron Back-Scattered Diffraction (EBSD) imaging. The obtained results confirmed obtaining a variable number of primary austenite grains in the cross-section of the tested casting, which significantly affects the strength properties of the obtained chrome cast iron casting.

Effects of Magnetic Field on Microstructure, Phase Transformation and Ferrite Growth in Directionally Solidified Gray Cast Iron

Effects of Magnetic Field on Microstructure, Phase Transformation and Ferrite Growth in Directionally Solidified Gray Cast Iron

Effect of metallic reinforcement and mechanically mixed layer on the tribological characteristics of Al-Zn-Mg alloy matrix composites under T6 treatment

Owing to their high strength, high specific modulus, low co-efficient of thermal expansion, and excellent wear resistance, aluminium metal matrix composites reinforced with hard ceramic particles are employed in different domains. The primary heat treatment method employed to enhance the desirable properties of heat-treatable aluminium alloys and their composites is T6 treatment. This study investigated the effects of metallic reinforcement and mechanically mixed layer on the tribological characteristics of Al-Zn-Mg alloy matrix composites. The microstructure, material transfer behavior, tribological characteristics, and wear mechanism of the worn surfaces were examined. A microstructural study revealed that the reinforcements would encourage grain refining, resulting in a 60.7% average size reduction. The wear rates have significantly reduced by 50.2% and 67.2%, respectively, with the introduction of 2.0 wt% of reinforcement and T6 treatment. There is a decreasing trend of wear rate as the weight percentage of reinforcement is increased, both in as-cast and peak-aged conditions. The refractory nature of precipitates formed during T6 treatment improves the hardness of the composite and thereby reduced the wear rate. Mechanically mixed layer (MML) is observed in the worn-out surface of peak-aged composites as revealed by the SEM analysis. Overall, the Al-Zn-Mg 6 wt. % grey cast iron composite showed excellent performance in tribological characteristics.

Contents

International Journal of Applied Ceramic TechnologyVolume 20, Issue 3 p. 1327-1330 ISSUE INFORMATIONFree Access Contents First published: 07 April 2023 https://doi.org/10.1111/ijac.14089AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract Cover Photograph: Si3N4-based ceramic cutting tools with high hardness and high toughness were prepared by introducing 2.5 vol% borides (ZrB2 or TiB2). The improvement of cutting performance for turning grey cast iron indicated that the boride-containing Si3N4 ceramics are expected to be used in the field of ceramic cutting tools. Cover credit: Sheng-Jin He, Si-Chun Luo, Wei-Ming Guo, Wan-xin Wei, and Hua-Tay Lin of Guangdong University of Technology. https://doi.org/10.1111/ijac.14280 Volume20, Issue3May/June 2023Pages 1327-1330 RelatedInformation

Thermal and Static Properties Investigation of Different Intake Manifold Materials to Lower Air Intake Temperature for Improved Engine Performance

Formula SAE competition is targeted at students who are interested in designing and developing a Formula-type race car. Rules were imposed to restrict the car’s performance for safety besides encouraging problem-solving skills. One such rule is the requirement of a 20mm restrictor inserted between the carburettor and intake manifold to reduce the air intake. With a constricted airflow creating a bottleneck effect, less air will be provided to the engine for combustion, consequently reducing engine efficiency. The purpose of this project is to overcome this problem despite the restriction imposed by the rules. This is done by choosing an intake manifold material that provides a low air temperature while withstanding the stress and vibrations from the engine. Computational Fluid Dynamics (CFD) software was used to conduct the static, thermal and modal analysis of Aluminium Alloy 6063, Gray Cast Iron, Fibreglass Epoxy and Carbon Fibre Epoxy to choose the material that produces lower intake air temperature while maintaining high strength. Carbon fibre epoxy was found to provide the best durability against static stress while maintaining a lower intake air temperature compared to the other materials tested.

A study on single plate clutch disc using finite element method

Clutch is an important mechanical device or mechanism between engine motor and its transmission framework used for connecting and gives mechanical coupling in the vehicle structure. There are two sorts of clutches positive and friction clutch, here the single type friction clutch plate has been chosen in this work. The Design and modelling of the single type friction plate clutch has been carried out done by a modelling software namely Creo and stress, strain, crack length analysis is done using Ansys software. The different materials selected for analysis is Grey Cast Iron (GCI), sintered iron, Aluminum alloy 7475 and Kevlar composites. The obtained analysis results were studied and made comparison with one another to select the best one for this clutch disc. The shear stresses, strain, fracture toughness and deformation obtained for all four materials using FEM in theoretical manner is then compared to analysis software results. The percentage error between analytical and theoretical results were also determined for fracture toughness values to all chosen materials.

394 R2* and QSM Reliability for Measuring Brain Tissue Iron Concentrations

INTRODUCTION: Pathologic levels of iron have been implicated in various neurological disease states, such as Parkinson’s, Multiple Sclerosis, Amyotrophic Lateral Sclerosis, and Stroke (hemorrhagic & ischemic). Using brain tissue iron concentration as a biomarker for disease progression has great potential for clinical translation; however, measuring iron concentrations non-invasively remains challenging. MRI based R2* and quantitative susceptibility mapping (QSM) values have been shown to correlate with iron levels in previous cadaveric studies. METHODS: Ten normal human subjects (ages 35-73) underwent test and retest MRI scans approximately 10 minutes apart. T1 and gradient-echo images were used to segment 7 regions of the brain bilaterally. The gradient-echo sequences were used to calculate the R2* and QSM for each region of interest. Iron concentrations were calculated from the R2* values based on R2* calibrated with a phantom. RESULTS: R2* values ranged from 19.45 Hz in the hand homunculus to 38.81 Hz in the substantia nigra and were consistent across 8-echo and 6-echo sequences. Mean QSM values ranged from -0.041 in the internal capsule to 0.046 in the globus pallidus. Calculated iron concentrations ranged from 52.1 mg/kg in the centrum semiovale to 104.6 mg/kg in the substantia nigra. Test and retest values showed consistency across brain regions for R2* with weighted coefficient variation percent of 3.9-9.6%. White matter iron concentrations ranged from 52.1-59.5 mg/kg, while deep grey nuclei iron concentrations ranged from 72.5-104.6 mg/kg. CONCLUSIONS: Our study demonstrates the ability of gradient-echo MRI to reliably measure tissue iron levels in non-disease states in healthy human subjects. Further research is needed to validate the ability of specific MRI sequences to be a surrogate biomarker in disease states.

ISO1083/JS/400-18-LT

Abstract ISO1083/JS/400-18-LT is a ferritic spheroidal graphite cast iron that has a minimum tensile strength of 400 MPa (58 ksi) and a minimum elongation of 18%, when measured on test pieces machined from separately cast samples. It has a tensile strength exceeding that of the highest-tensile-strength grade of gray cast iron, together with much higher elongation and impact resistance. It is specifically designed to provide good impact properties at low temperature. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on casting and heat treating. Filing Code: CI-104. Producer or source: International Organization for Standardization.

Research into the relationship of mechanical properties of grey cast iron through acoustic non-destructive testing

The following acoustic characteristics are measured in this study: the velocity of longitudinal waves Cl and the attenuation coefficient of ultrasound δ in samples of grey cast iron, which are obtained by centrifugal casting. The correlations between the mechanical properties, the acoustic non-destructive testing characteristics and the structure formation of the test specimens of cast iron with flaked graphite are studied. The study shows that data on the structure formation can be obtained, followed by the mechanical properties, hardness and tensile strength, by measuring the speed and attenuation of the ultrasound.

Transient Analysis on Excavator Bucket with Gray Cast Iron and Vanadium

Abstract: The excavator machines are power machines used in the Agricultural, Mining and Construction industry. The main purpose of this excavator is for digging, ground leveling and material transport operations etc. The excavator bucket part is subjected to various load forces. So in this project, the work is carried on the bucket by interchanging the composite materials like gray cast iron and vanadium. Since the bucket experienced so many loads like impact during digging transient analysis is carried out, the standard specimen prepared through stir casting technique and conducted tests on the specimen like tensile, compression, hardness, and impact test to validate the data. The main objective of this project is to design an excavator bucket using CATIA V5 software of 3-D modeling software. Then simulation did through ANSYS 19.2 software by transient analysis technique to know the deformation and stresses etc. And the results of deformation and stress are compared between Gray Cast Iron without Vanadium and Grey Cast Iron with Vanadium for comparing justified result.

Quench hardening effect of gray iron brake discs on particulate matter emission

In this study, particulate matter produced during the braking of motor vehicles was investigated. In particular, this study focused on the effect of quench hardening of gray iron discs on brake emissions. The disc hardening effect was evaluated with commercial low-steel and non-steel brake pads using a 1/5 scale inertial brake dynamometer equipped with a particle counter. The results indicate that the disc hardening effect was significantly affected by the type of friction material due to different wear mechanisms. The low-steel brake pads produced more brake emissions when using the quench-hardened disc due to the increased aggressiveness of the hardened disc against the brake pad. In contrast, the hardened disc substantially reduced particulate matter emission when using the non-steel brake pads because the pad's surface became more wear-resistant due to the smaller amount of iron transferred from the hardened disc compared to conventional gray iron discs. These results suggest that the iron transfer from the disc to the pad's surface plays a crucial role in brake emissions.

Inhibitive effect of 8-hydroxyquinoline on corrosion of gray cast iron in automotive braking systems

The inhibition effect of 8-hydroxyquinoline (8-HQ) on the corrosion of gray cast iron rotors for automotive applications was studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in a 0.1 M HCl solution. The experimental results suggest that the 8-hydroxyquinoline is a mixed inhibitor reducing both the anodic and the cathodic current densities. Besides, EIS results indicate that the inhibitor provides a stable protection over 9 days of exposure to the electrolyte due to the cooperative formation of an adsorbed layer of 8-HQ on the rotor and a top layer probably constituted by a complex between 8-HQ and iron. The presence of the adsorbed layer and the complex with 8-HQ was confirmed by means of Energy Dispersive X-ray analysis (EDX) and Fourier-transform spectroscopy (FT-IR).

Synergy Study Between a Lubricant Oil Layer and a Microstructural Graphite to Reduce Friction and Wear of a Thermally Modified Low-Carbon Gray Cast-Iron Cylinder Liner

The results of a sliding wear tests on base and thermal treated gray cast iron (GCI) samples from internal combustion engine cylinder liner are reported here for dry and lubricated conditions. A thermal treatment was applied to samples of 10 x 10 mm to avoid the effect of residual stress and to obtain the microstructure of interest. Tribological tests were carried out up to 27000 cycles at room temperature. A frequency of 15 Hz, a stroke amplitude of 6 mm, and a maximum contact pressure of 1.12 GPa were selected. Under the unlubricated settings, a noticeable decrease in friction coefficient and specific wear rate are attributed to the appearance of irregular graphite nodules in the heating–quenching process. The significance of thermal treatment applied to low carbon cast iron in the derived self-lubricating function and its synergistic role with the oil lubricant is discussed. In this context, this work illustrates, for the first time, how the change in the morphology from flake graphite to irregular nodule graphite positively determines the reliability of gray casting irons.

Plasticity Resource of Cast Iron at Deforming Broaching

The contact interaction mechanics of deformation broaching in low-plasticity materials is studied. Particular attention is paid to the study of the stress–strain state parameters and the plasticity margin in the deformation zone during the machining of gray cast iron EN-GJL-200. The stress–strain state was analyzed using a finite-element model of the deforming broaching process for each area of the deformation zone. The model parameters of the machined material were determined experimentally by compressing specimens of gray cast iron EN-GJL-200. The changes in the parameters of accumulated strain, stress tensor components, stress triaxiality ratio, hydrostatic stress, and plasticity margin at different deformation zones along the machined specimen depth are analyzed. It is shown that there is a zone of local plastic deformation in conditions of critical contact stresses. This leads to the appearance of tensile stresses that reduce the plasticity margin in the surface layer. The impact of tool geometry on the stress–strain state of the surface layer is also discussed, and recommendations for the optimal working angle of the deforming element are provided based on plasticity margin minimization.