A comparison of the oxygen, nitrogen and hydrogen content in ductile iron castings and their effect on microstructure and mechanical properties

Two different spheroidization methods were compared in terms of the effect they may have on gas content (oxygen, nitrogen and hydrogen) in ductile iron castings and process efficiency. Two methods of cast iron treatment were investigated, i.e. spheroidization in the foundry mould using a reaction chamber (reactor) developed by the Foundry Research Institute and, as a reference, the method currently used by foundry shops, i.e. spheroidization in the foundry ladle. The effect of spheroidization process was evaluated on test castings. The results of metallographic examinations and mechanical tests as well as the results of measurements of the oxygen, nitrogen and hydrogen content in cast iron after spheroidizing treatment were presented.