SPHERICAL GRAPHITE CAST IRON, CAST ARTICLE AND AUTOMOBILE STRUCTURAL COMPONENT COMPRISING SAME, AND METHOD FOR MANUFACTURING CAST ARTICLE COMPRISING SPHERICAL GRAPHITE CAST IRON

摘要

A spheroidal graphite cast iron meeting N_(5-) ≥ 250, N(_5-20)/N_(5-) ≥ 0.6, and N_(30-)/N_(5-) ≤ 0.2, wherein N_(5-) represents the number (/mm²) of graphite particles having equivalent-circle diameters of 5 µm or more, N_(5-20) represents the number (/mm²) of graphite particles having equivalent-circle diameters of 5 µm or more and less than 20 µm, and N_(30-) represents the number (/mm²) of graphite particles having equivalent-circle diameters of 30 µm or more, among graphite particles observed in an arbitrary cross section of at least 1 mm².