The paper presents issues related to the technology of layered castings manufactured in the system: working part made of high-chromium steel X46Cr13 - base part made of gray cast iron with flake graphite, using the mould cavity preparation technology. Considering the high hardenability of the above-mentioned steel grade, the aim of the research was to optimize the casting parameters of gray cast iron in such a way that it would be possible to perform heat treatment of X46Cr13 steel directly in the casting mould. As part of the research, the geometry of the working and base parts of layered castings was selected, and guidelines for mould technology from the point of view of the moulding sand were developed. In order to control the cooling rate, three matrix of the moulding sand were used - quartz sand, chromite sand and silicon carbide, with the same granularity. The thermal conductivity coefficient of sands made on selected matrix, bound with synthetic resin in the ratio of 30:1, was experimentally determined. Then, the bimetal casting process in a given mass was simulated in the MagmaSoft® (ver. 5.4.1). The purpose of the simulation was to determine the maximum virtual temperature Tm in the thermal center of the outer surface of the X46Cr13 steel insert. From the point of view of the research purpose, the insert was expected to heat up to the austenitization temperature, i.e. at least 950°C.

The paper presents the results of studies on the development of manufacturing technologies to cast hearth plates operating in chamber

furnaces for heat treatment. Castings made from the heat-resistant G-X40CrNiSi27-4 steel were poured in hand-made green sand molds.

The following operations were performed: computer simulation to predict the distribution of internal defects in castings produced by the

above mentioned technology with risers bare and coated with exothermic and insulating sleeves, analysis of each variant of the technology,

and manufacture of experimental castings. As a result of the conducted studies and analysis it was found that the use of risers with

exothermic sleeves does not affect to a significant degree the quality of the produced castings of hearth plates, but it significantly improves

the metal yield.