抄録
A study was performed to clarify the effects of pig iron and alloy elements upon the as cast microstructure and mechanical properties of SG iron. Melting was made in an induction furnace of 50kg capacity and Kriptal furnace. The melt was treated with Fe-Si-Mg alloy and the results obtained were: 1) Elongation of SG iron attained over 20% when it was made from either low manganese pig iron of high purity or OB pig iron produced in Norway, while it was only 6% when SG iron was made from steel scrap. 2) When steel scrap of higher manganese content was added to the melt of low manganese pig iron, both elongation and impact value of SG iron were decresed in proportion with the increase in steel scrap addition. 3) When manganese was added to the melt of pig iron of high purity, it had no effect upon the structure and the mechanical properties of SG iron, so far as the manganese content did not exceed 0.3%. But, if it exceeded 0.3%, itresulted in increasing pearlite, which had harmful influences upon the elongation and the impact value. 4) In the experiments in which the L16 (215) type of orthogonal arrangement of experimental designs was used, there were found main effects of Mn, Ti and P% upon elongation, accompanied by interacted effects of Ti-Mn, Ti-Cu and Ti-P.
