The Influence of metallic charge on metallurgical quality and properties of ductile iron

Abstract

The effect of pig iron, steel scrap and ductile iron returns content in metallic charge on the nucleation potential and metallurgical quality of the base iron and ductile iron and the final microstructure and tensile properties of ductile iron is analyzed in this paper. The obtained results confirm the beneficial effect of pig iron addition on the nucleation potential of base and ductile iron producing an increase in nodule count and a decrease in chilling tendency of both base and ductile iron. The steel scrap has a price much more convenient than pig iron, but the use of high percentage of steel scrap in the charge was limited due to decrease in nucleation potential and increase of chilling tendency. Ductile iron returns also contributed to lower nucleation. Preconditioning did not completely correct the negative effect of high percentage of steel scrap in metallic charge. The results showed that the base iron must have had enough nucleation potential in order to obtain efficient inoculation. It was found that the tensile properties of ductile iron, especially the elongation, increased with the increase of the percentage of pig iron in metallic charge, due to increase of nodularity and nodule count. K e y w o r d s : ductile iron, metallic charge materials, metallurgical quality, nucleation potential, thermal analysis

Structural Characterization and Mechanical Properties of Ductile Iron - Enhanced Alloyed Ductile Iron

“…The spheroids were noted well distributed in the matrix of the ductile iron. The count of spheroids and the evolved structures nodularity are the virtuous pointers of the good mechanical characteristics in the ductile irons, in accordance with (Z. Glavas, 2011)[16].…”

Effect of Cobalt in Thin Wall Ductile Iron and Solid Solution Strengthened Ferritic Ductile Iron

“…The decrease in carbon content was confirmed from the chemical composition analysis, as this heat had carbon concentration of 3.68 wt.%, which is below the average of 3.75 wt.% C. The above findings are consistent with prior studies [106]- [108] where they have noted the detrimental effects of long holding times of the base iron in the induction furnace, resulting in lower nodule counts and nodularity because the nucleation has been limited.…”

Influence of Residual Elements Contained in Steel Scrap for the Production of Nodular Cast Iron

“…Commercial ductile cast iron may present in its microstructure ferrite, perlite, ferrite-pearlite, cementite, martensite or ausferrite 5 . These phases can be obtained in the casting process by the chemical composition of the raw material, melting temperature, pouring temperature, inoculation, nodulization, cooling rate during solidification and by heat treatments 3,[5][6][7][8] .…”