This paper studies the possibility of producing ductile iron castings intended for extreme conditions on an industrial scale. The preparation of charge and its melting conditions, modification, primary inoculation and main inoculation were studied within extensive series of experimental melts. In the scope of charge evaluation, especially the ratio of sorel type raw iron to steel charge was studied in order to reduce the raw iron portion while maintaining the castings qualitative requirements. The modifiers FeSiMg621 and FeSiMg731 were evaluated during modification. During primary inoculation the inoculants Inocast100 and SB10 were compared. The inoculation blocks Germalloy were used during main inoculation. The implementation of experimental melts was followed by chemical composition analysis, metallographic evaluation and a study of microstructure and mechanical testing performance of samples. The chemical composition was determined based on optical emission spectrometry and combustion analysis. The metallographic analysis and the microstructure evaluation were made using an optical microscope and image analysis. Testing of mechanical properties was focused on the tensile test, impact test and hardness test. It was proved that the foundry was able to produce the required quality ductile iron made of different combinations of charge materials, modifiers and inoculants. All contemplated combinations of the production technology meet the standard-defined requirements for this type of material.

Presented paper deals with the technology of production of ductile iron on industrial scale. Particularly, the material in question is EN-GJS-400-18-LT, which is suitable for castings intended for extreme conditions. Drawing on previous works, most attention has been paid to the implementation of the cored wire technology for modification and primary inoculation. Two technological options were compared, namely modification and primary inoculation by the pour method in the ladle and modification and primary inoculation by the cored wire using a twin-core feeder. Test samples within the inlet system of the moulds were cast during the pouring process to analyse the chemical composition, evaluate the microstructure and perform mechanical tests without interfering with the casting itself. The chemical composition was determined by optical emission spectrometry and combustion analysis. Metallographic analysis and microstructure evaluation were performed by optical microscopy and image analysis. Mechanical properties testing was focused on tensile test, impact test and hardness test. It was demonstrated that the foundry is capable of producing ductile iron of the required quality with the adoption of modern cored wire technology.

The technology of high-pressure die casting thin-walled castings requires increased demands on the stability of technological processes and pressure casting parameters. The wall thickness of the studied zinc alloy castings (ZP0410) ranges from 0.4 to 1.2 mm. In general, it is necessary to use higher mould operating temperatures and a higher casting speed when filling the mould cavity when casting thin-walled castings. There is an increased load on the mould (tool) and the die casting machine during this casting process and the use of more demanding parameters. It results in a shortening of mould service life. There is currently no own returnable material (alloy ZP0410) used in the given production conditions in the production of thin-walled castings. Only the primary alloy ZL0410 is used now. It must be emphasized that the ability to implement the recycling of these returnable materials is becoming increasingly important. However, it is necessary to ensure that the quality of production is not reduced. The research was carried out aimed at determining the current state. Methods of roughness analysis, computed tomography, and metallography of casting defects from casting machine failures even after plating are used in the study of existing production technology in addition to standard long-term monitoring of melt quality. The findings of these research activities were briefly summarized in the paper. The experimental development of the technology of using our own returnable material in this quality-intensive production is in progress now.