Papers by Keyword: Cast Iron

Abstract: Glass containers are manufactured by pressing or blowing a hot glass gob (700-1200°C) onto a metallic mould. Beside forming the glass, moulds are heat exchangers for cooling down the glass final product. To this goal, moulds are made of cast iron or copper-nickel alloy due to their thermal properties. If copper-nickel (nickel aluminium bronze) is the most efficient material, cast iron is mainly used for economic purposes. To enhance the properties of the cast iron mould, cold spray coating of a copper-nickel alloy is investigated. Optimization of the parameters process such as spraying temperature (800-1000°C), pressure (40-50bar) and gun’s travel speed (200-400mm/s) lead to a dense and well-bonded “bronze” coating on cast iron. Microstructural analysis is performed thanks to Optical Microscope, Scanning Electron Microscope, Electron BackScattered Diffraction, X-Rays Diffraction and microhardness tests. Finally, a simple thermal experiment has been designed for demonstrating thermal performances of the coating-substrate couple.

Abstract: The present research work focuses on the study of the microstructure evolution, corrosion resistance, and mechanical properties of GG25 grey cast iron and AISI 4140 microalloyed steel dissimilar brazing joints, using a eutectic type Ag-based filler metal. The welding zone microstructure study was carried out through optical (OM) and scanning electron microscopy (SEM), in conjunction with an energy-dispersive X-ray detector (EDS). Joints’ mechanical properties were investigated through tensile tests, as well as detecting the Vickers microhardness across the microstructure’s zones. For the assessment of the joints’ corrosion resistance, potentiodynamic polarization tests were performed in 3.5 wt% NaCl solution, at various temperatures. The corrosion products evaluation was carried out by both X-ray Diffraction (XRD) and scanning electron microscopy (SEM). According to the results, sound brazing joint was attained, presenting an average tensile strength and ductility of about 230 MPa and 20 %, respectively.

Abstract: Since the end part of the valve of the gas distribution mechanism is subjected to not only wear but also fatigue painting during operation of the car, this article proposes to remove the worn out layer of cast iron in several ways to avoid problems of renovation of parts of the gas distribution mechanism.

Abstract: The present paper deals with the determination of the mechanical and physical properties of the heavyweight concrete formulation used in the shielding construction of the reactor casing power plant. The recipe includes the use of baryte and cast-iron crumbs as fillers for the preparation of heavyweight concrete. The binder paste was obtained using CEM I 42.5 R with w/c ratio = 0.44 and a lignosulfonate-based plasticizer prepared according to the used Ralentol plasticizer's standard requirements, which is currently no more produced. The result of the concrete slump according to the S -cone was S1 (1 cm slump). The bulk density of fresh and hardened concrete was over 4000 kg m^-3. The compressive strength at 28 days exceeds 80 N mm^-2 and the flexural strength is 4 N mm^-2. The modulus of elasticity is 40 GN m^-2. The shrinkage of concrete is 0.52 ‰. The weight loss due to shrinkage rises to almost 1.3 %. The thermal properties of the heavyweight concrete are as follows: the thermal conductivity λ is 2.2 W m^-1 K^-1; the thermal resistance R for thickness d = 1 m is 0.44 m² K W^-1; volume heat capacity c_ρ rises to almost 2 J m^-3 K^-1 and thermal diffusivity a 10^-6 drops to 1,15 m² s^-1.

Abstract: The article considers issues of increasing wear resistance of cast iron products by methods of thermochemical treatment of their surface layer. Methods are proposed to solve the problem of wear from cast iron of grade EN-JS1060 due to development of technological processes of strengthening treatment. Alternative versions of strengthening technologies are represented by nitrocarburizing, liquid nitriding and carbonitration. Results of examination of control samples at increasing loads after 200 N before catastrophic wear are given. Comparative analysis of these results showed that samples after carbonitration and liquid nitriding had the greatest bearing capacity (1000 N). Carbonitration is selected as a most preferred option of the surface hardening treatment. Non-poisonous cyanoacid salts are used to realize it.

Abstract: Laser surface modification technology is one of the most advanced technologies, which uses laser to modify the characteristics of the surface to offer superior performance for various industrial applications. In this study, laser surface hardening behavior of GM246 case iron was investigated. Result shows that excellent laser surface hardening of GM246 cast iron need low power density and scanning speed. With power of 2500 W, scanning speed of 300 mm/min and power density of 2500 W/cm², the laser surface hardening of GM246 cast iron achieved the hardness of 790HV, which was 2-3 times higher than the hardness of base metal. Also, the depth of laser surface hardening case achieved 0.9 mm and the hardening case demonstrated three subzones.

Abstract: The model for evaluation of quality of ladle graphitizing inoculation of cast iron, according to the most common technological schemes, using the triple integral, is proposed and implemented. The necessary boundary conditions and parameters of the integral model are presented, described and justified. A concrete example confirms the practical conclusion that graphitizing inoculation of cast iron, melt into a stream in the process of filling a mold, is preferable.

Abstract: We conducted comparative tests of the wear resistance of metals operating under abrasive conditions. Samples were cut from the working parts of mixer-pneumosuperchargers. The chemical composition and mechanical properties were determined. To compare samples under abrasive wear conditions, we designed and assembled a carousel installation. The principle of its operation is based on mixing the abrasive medium by the samples being studied with a given speed. Wear resistance was evaluated by weight loss by samples after several test cycles. To determine changes in the structure of the metal during abrasive wear, metallographic studies of the samples were carried out before and after the tests. It is shown that the best complex of service and mechanical properties is possessed by 110G13L steel.

Abstract: Properties of cast iron on the bimetallic part depend on the initial structural state of the cladded cast iron and technological parameters of its induction cladding process. Methodology of predicting the properties of the cast iron in the bimetallic valve tappets ICE largest hardness billets was used for cladding, the silicon content in the alloy cladding and the technological parameters of the process, as well. A hereditary relationship between the initial state of the cast iron of the semi-finished product, used for induction cladding, and the structural state of the layer of weld on the steel base of the part, has been established.

Abstract: A brake disc has an significant role in the vehicle and it is used to stop or decrease the velocity of the vehicle. The demand of metal matrix composites (MMCs) is greatly increased in fabricating the brake disc since it possesses a low density and high thermal conductivity. Over-heating will lead to the malfunction of the braking system and affect the safety of vehicle. Reduced weight of brake disc can decrease the use of fuel of the vehicle thus improve the fuel usage efficiency. This paper is focussed to determine the suitability of AlSiCGr hybrid MMCs compared to cast iron in terms of thermal and structural properties for brake disc. Both design of brake discs was proposed and modelled using CATIA and then imported to ANSYS software for structural and thermal analysis. The simulation results showed that AlSiCGr hybrid MMCs brake disc has higher thermal and structural performance compared to the original cast iron brake disc.