Investigation of Grey Cast Iron Microstructure Influence on its Heat Resistance

Abstract

Grey cast iron is one of the most common engineering materials used to make castings which work in thermal cycling. Under thermal cycling conditions, heat resistance is an important operational property of grey cast iron, which depends to the greatest extent on its structure – size and shape of the graphite inclusions, as well as the metal matrix composition. In this paper, the heat resistance of unalloyed grey cast iron with lamellar and compact graphite distributed in perlitic and perlitic-ferritic metal matrices was determined. The tests were carried out at temperatures of 500 – 800 °C. The results of the studies showed an insignificant difference of perlitic and perlitic-ferritic grey cast iron with lamellar graphite heat resistance. The heat resistance of perlitic ferritic grey cast iron with compact graphite is 16 – 48 % higher than the heat resistance of perlitic ferritic grey cast iron with lamellar graphite. Thus, when the shape of the graphite inclusions changed from lamellar to compact, a significant increase in the heat resistance of unalloyed grey cast iron occurred.

Research of Alternative Options for Strengthening Surface Treatment of Cast Iron Products

“…However, the service life of cast iron parts at high specific loads and, especially in the case of abrasive particles entering the friction zone, is low. Prolonging the service life of cast iron parts containing wear-resistant and corrosion-resistant coatings is an urgent task, as it makes it cheaper for products equipped with such parts [12,13]. Production of hardened surface layers is achieved by purposeful formation of specified structural state of metal by methods of thermochemical treatment, including using highly concentrated energy sources, such as ion, laser, ultrasonic, high-frequency induction and others [14 -17].…”

Modifying of the Surface of Products from Cast Iron as the Element of Production Modernization

“…Cast irons of grades EN-GJL-250 and EN-JS1060 were chosen as the studied materials. These grades of cast iron are applied to production of the most wearing parts of transport and agricultural machinery of various category of complexity working in the conditions of a dry sliding friction and friction with lubricant [17][18][19][20]. However, the resource of work of such details in the conditions of high specific loadings and especially in case of hit in a friction zone of abrasive particles is low [20].…”

Technology for producing cast iron castings with compact graphite by top filling

“…Considering the fairly wide range of grades of high-strength cast iron used for the manufacture of castings for car parts, a step-by-step approach to their development is the most justified and rational [1][2][3][4]. In particular, castings from low grades of high-strength cast iron (ChVG40, VCh50), having less stringent requirements for microstructure and properties (the predominance of the ferrite component of the structure and SSG ≥ 80% [5][6][7]), can be obtained in a somewhat simplified manner both in terms of labor intensity, and the complexity of the equipment and technology used. The most widespread and well-proven in practice "sandwich" process in an open ladle can be used to modify high-strength cast iron only in ladles with a height to average diameter ratio of 2...2.5:1 [8,9].…”