Journal of Casting & Materials Engineering
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ISSN 2543-9901
Issue Date
2017
Volume
Vol. 1
Number
No. 4
Description
Journal Volume
Journal of Casting & Materials Engineering
Vol. 1 (2017)
Projects
Pages
Articles
Microstructure and mechanical properties of rope drum casting
(AGH University of Science and Technology Press, 2017) Futáš, Peter; Pribulová, Alena; Mahút, Dávid; Bartošová, Marianna; Junáková, Andrea
Ductile iron is a high-carbon-containing iron-based alloy in which the carbon, as graphite, is present in a spheroidal shape. With its good mechanical properties, ductile iron approximates the properties of steel and the cost per unit of strength compared to other materials. With suitable metallurgical treatments, we can influence its microstructure and resulting properties. Incorrect manufacturing technology and metallurgical processes give rise to casting defects and decreased mechanical properties. The contribution is devoted to measures to prevent the occurrence of defects in the casting of rope drums and to achieve the required mechanical properties of these castings. The most-common defects in these castings are micro-shrinkages in casting heat centers and unsatisfactory mechanical properties such as tensile strength, yield strength, and elongation.
Determination of binder content in traditional sandmixes by microwave method
(AGH University of Science and Technology Press, 2017) Nowak, Daniel
This paper presents preliminary research on the possibility of determining the binder content in traditional sandmixes by the microwave method. The research included examinations of three kinds of bentonite. The presented measurements were carried-out with the use of a special stand - the so-called slot line. The concentration of the binder in molding sand was determined on the grounds of measurements of a parameter, i.e., absorbed power or output power of the electromagnetic wave. One of the main advantages of the suggested new method is the short time of the measurement.
Application of computer support for design of shaft furnaces - cupolas
(AGH University of Science and Technology Press, 2017) Dajczer, Grzegorz; Dańko, Rafał
Designing a machine's constructions and an object's structures is one of the areas of technology design. The complexity of the structure is defined by the technology for which it is used. Following the theory of construction and mechanisms, the full characteristics of a machine or device is defined by its shape and operating parameters. The shape reflects geometry. As a result of using the correct parameters, the construction should functional correctly (which means according to its general principles of operation). The project of any structure is a creative process performed by a team of designers and constructors. The contemporary design is not solely based on the personal preferences of engineers. More and more scientific and computerized design methods are being introduced to this process. They are characterized as computer-aided systems and are based on algorithms, programs, and IT equipment. This article presents the methodological application of computer-aided design on an example of the design of shaft furnaces that are used in foundries as cast iron smelters. These furnaces, called cupolas, have again become objects of interest for research. In the design of the cupola construction, Autodesk Inventor techniques were used.
Influence of process parameters on ceroxide formation in low-carbon steels
(AGH University of Science and Technology Press, 2017) Vaucheret, Alexis; Nicoli, Cécile; Carton, Jean-François; Jacquet, Philippe
Ceroxides are surface defects caused by a mold-metal reaction during the casting process of steels. This type of defect may affect a large area, but it is located only on the skin of the parts. It does not affect the core of the parts nor its mechanical properties. Nevertheless, ceroxides induce a lack of material on the surface, forming a kind of crater and needing complementary surfacing. The defect is also composed by several non-metallic inclusions containing Al, Mg, Si and O. An EDX analysis by mapping show these elements involved in the mold-metal reaction. The presence of these oxides could confirm the hypothesis of the deoxidizer reoxidation found in the bibliography. To better understand the specific conditions of ceroxide formation, the first step was to find of way to generate systematically this defect at each casting. Two patterns with different filling rate were designed, simulated on Quikcast and tested. The pattern with turbulent filling rate allowed the formation of ceroxide at each casting and so was used during this study. This result shows that the filling rate of the mold could be considered as a first order parameter in ceroxide formation. Then, a specific experimental set up was designed to characterize this defect. The analysis of the defect was done for sizing it: surface and depth. Finally, some key parameters on defect formation were determined like the nature of deoxidizer or the amount of oxygen in the mould. Some laboratory tests were lead to show the influence of these parameters by characterization of the casted parts in comparison with a reference sample. This study allowed us to find process parameters responsive of ceroxide formation and to propose some way of improvement to reduce the size and the occurrence of ceroxides.
Deoxidation impact on non-metallic inclusions and characterization methods
(AGH University of Science and Technology Press, 2017) Nicoli, Cécile; Carton, Jean-François; Vaucheret, Alexis; Jacquet, Philippe
Deoxidation is an unavoidable step in the elaboration of steel. The study of its influence could improve the quality of low-carbon steel (0.20-0.25 wt.% of carbon). There are many deoxidation methods, and the most-common one consists of adding aluminum. Although it is a classic method, determining the optimal process parameters (quantity, yield, etc.) could be very sensitive. Deoxidation plays a determining role on inclusion cleanliness, especially on sulfide morphology. In order to control the efficiency of deoxidation, different techniques can be used. In this paper, an automated counting procedure on a scanning electron microscope with a field emission gun (FEG-SEM) is presented. This method was applied on samples cast in our laboratory under different deoxidation conditions. According to this, the resulting inclusion population is correlated with the aluminum content to find the optimal process parameters.