DOI: 10.18503/1995-2732-2024-22-3-43-51
Abstract
A currently relevant task of optimizing the lost foam casting technology is to reduce defects of castings. This is due to an increase in technical and economic indicators of production and increasingly strong consumer requirements for the product quality. Special attention is paid to critical duty parts with the required long-term trouble-free operation. Defects in formed parts made of high-strength cast iron with spherical graphite reduce strength and increase the likelihood of breakthroughs and emergencies. The most dangerous defects in operation of pipeline parts are discontinuities in the casting body. This research is aimed at studying the features of the morphological structure and a chemical composition of the formed reaction products on the surface of exogenous defects. We used scanning electron microscopy methods with the possibility of determining an X-ray microanalysis. Studies on a chemical composition of the defect surface contributed to correlating the elements on the surface of gas pores, cracks and cavities with the elements contained in casting materials: a modifier, non-stick paint and the molding mixture. The X-ray microanalysis showed that products and films were formed on the surface of defects. They are characterized by a complex chemical composition with a high content of carbon and oxygen. This may indicate complex mechanisms of formation of gas defects. Based on the generally accepted aspects of the theory of foundry processes and the obtained X-ray microanalysis results, we have proposed possible mechanisms and causes of defect formation. The results described in this paper are useful for engineers of the technical control department to identify defects efficiently and process engineers to establish the causes and sources of their formation. This will optimize the production technology of castings made of cast iron with spherical graphite.
Keywords
gas defects, high-strength cast iron, lost foam casting, scanning electron microscopy, micro X-ray spectral analysis
For citation
Yurov V.V., Tsyganov I.A., Pripadcheva N.A. Identification of Defects of Gas Nature in Parts Made of High-Strength Cast Iron with Spherical Graphite Manufactured According to the Lost Foam Casting Technology. Vestnik Magnitogorskogo Gosudarstvennogo Tekhnicheskogo Universiteta im. G.I. Nosova [Vestnik of Nosov Magnitogorsk State Technical University]. 2024, vol. 22, no. 3, pp. 43-51. https://doi.org/10.18503/1995-2732-2024-22-3-43-51
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