| 摘要 |
A spheroidal graphite iron for cylinder head of an internal combustion engine, the spheroidal graphite iron having a tensile strength in the range 350 – 480 Mpa and a thermal conductivity in the range 38 – 45 W/(K*m), and the composition in percentage by weight: 3,0 to 4,5% of carbon (C ), 0,9 to 1.75% silicon (Si), less than 0,8% manganese (Mn), less than 0,3% copper (Cu), 0,03 to 0,25% Vanadium (V), and 0,01 to 0,1% niobium (Nb), the rest being iron (Fe) and unavoidable impurities. The spheroidal graphite iron comprises a microstructure of at least 75 vol-% ferritic, which is precipitation hardened. |
