In the family of iron-based alloys, ductile iron enjoys the highest rate of development, finding application in various industries. Ductile iron or the cast iron with spheroidal graphite can be manufactured by various methods. One of them is the Inmold spheroidization process characterized by different technological solutions, developed mainly to increase the process efficiency. So far, however, none of the solutions has been based on the use of a reactor made outside the casting mould cavity. The method of spheroidization inside the casting mould using a reaction chamber developed at the Foundry Research Institute is an innovative way of cast iron treatment. The innovative character of this method consists in the use of properly designed and manufactured reactor placed in the casting mould cavity. Owing to this solution, the Inmold process can be carried out in moulds with both horizontal and vertical parting plane. The study presents the results of examinations of the microstructure of graphite precipitates and metal matrix of castings after spheroidization carried out by the Inmold process using a reactor and mould with vertical parting plane. Special pattern assembly was made for the tests to reproduce plates with wall thicknesses of 3; 5; 7; 10; 20 and 30 mm. The content of residual magnesium was determined for all tested castings, while for castings of plates with a wall thickness equal to or larger than 10 mm, testing of mechanical properties was additionally performed.

The paper presents the issue of synthetic cast iron production in the electric induction furnace exclusively on the steel scrap base. Silicon

carbide and synthetic graphite were used as carburizers. The carburizers were introduced with solid charge or added on the liquid metal

surface. The chemical analysis of the produced cast iron, the carburization efficiency and microstructure features were presented in the

paper. It was stated that ferrosilicon can be replaced by silicon carbide during the synthetic cast iron melting process. However, due to its

chemical composition (30% C and 70% Si) which causes significant silicon content in iron increase, the carbon deficit can be partly

compensated by the carburizer introduction. Moreover it was shown that the best carbon and silicon assimilation rate is obtained where the

silicon carbide is being introduced together with solid charge. When it is thrown onto liquid alloy surface the efficiency of the process is

almost two times less and the melting process lasts dozen minutes long. The microstructure of the cast iron produced with the silicon

carbide shows more bulky graphite flakes than inside the microstructure of cast iron produced on the pig iron base.