STUDY OF THE THERMOPHYSICAL AND PHYSICAL - MECHANICAL PROPERTIES OF HIGH-ALLOYED ALUMINUM CAST IRON CHYU22SH

Abstract

Highly alloyed alloys, in which expensive chromium and nickel are alloying elements, are widely used as heat-resistant materials. Their total content in heat-resistant alloys reaches 30% or more. However, the life of working parts made of heat-resistant alloys is limited. Moreover, the higher the operating temperature, the shorter it is. This leads to increased costs for maintaining the units in working condition. Examples of such parts are the grate of agglomeration machines, details of boiler plants, roasting, heating, and glass melting furnaces, casting molds, exhaust manifolds of forced automobile engines, etc. In this regard, reducing the cost of heatresistant products, while maintaining their operating characteristics and life, becomes very actuality. One of the promising options to solve it is to manufacture these parts made of high-alloyed heat-resistant aluminum cast iron CHYU22SH (CHYU22SH - standard cast iron). Castings made of cast iron CHYU22SH differ, first of all, by being heat resistance at high temperatures in air (up to 1100°C) and in media containing sulfur, sulfur dioxide, oxides of vanadium, and water vapor. In addition, they can functionally operate as a wear-resistant product having high strength at normal and elevated temperatures. The paper presents the thermal and mechanical properties of casting, as well as the results of microstructure analysis of aluminum cast irons. The results of analyses and tests show that cast iron CHYU22SH can be obtained by casting with long walls of a thickness of 4 mm without external and internal defects. By doing so the castings have a uniform structure, high and stable mechanical properties, as well as lower by ~17-24% weight than similar cast of gray iron. The results of experimental - industrial testing laboratory studies confirm the influence of solidification conditions on the parameters of the structure of cast iron CHYU22SH.