Consecutive casting of bimetallic applies consecutive sequences of pouring of two materials into a sand mold. The outer ring is made of NiHard1, whereas the inner ring is made of nodular cast iron. To enable a consecutive sequence of pouring, an interface plate made of low carbon steel was inserted into the mold and separated the two cavities. After pouring the inner material at the predetermined temperature and the interface had reached the desired temperature, the NiHard1 liquid was then poured immediately into the mold. This study determines the pouring temperature of nodular cast iron and the temperature of the interface plate at which the pouring of white cast iron into the mold should be done. Flushing the interface plate for 2 seconds by flowing nodular cast iron liquid as inner material generated a diffusion bonding between the inner ring and interface plate at pouring temperatures of 1350 °C, 1380 °C, and 1410 °C. The interface was heated up to a maximum temperature of 1242 °C, 1260 °C, and 1280 °C respectively. The subsequent pouring of white cast iron into the mold to form the outer ring at the interface temperature of 1000 °C did not produce a sufficient diffusion bonding. Pouring the outer ring at the temperature of 1430°C and at the interface plate temperature of 1125 °C produced a sufficient diffusion bonding. The presence of Fe3O2 oxide on the outer surface of the interface material immediately after the interface was heated above 900 ⁰C has been identified. Good metallurgical bonding was achieved by pouring the inner ring at the temperature of 1380°C, interface temperature of 1125 °C and then followed by pouring of the outer ring at 1430⁰C and flushing time of 7 seconds.

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.