SPHERICAL GRAPHITE CAST IRON FOR AN ENGINE EXHAUST SYSTEM

摘要

The present invention relates to a nodular graphite cast iron for an engine exhaust system. The nodular graphite cast iron comprises: 3.0-3.4 wt% of carbon (C), 4.2-4.5 wt% of silicon (Si), 0.1-0.3 wt% of manganese (Mn), 0.002-0.01 wt% of sulfur (S), 0.05 wt% or less of phosphorus (P), 0.035-0.055 wt% of magnesium (Mg), 0.9-1.2 wt% of molybdenum (Mo), 0.2-0.5 wt% of nickel (Ni), 0.4-0.6 wt% of vanadium (V), 0.1-0.4 wt% of niobium (Nb), 0.005-0.01 wt% of cerium (Ce), 0.003-0.007 wt% of aluminum (Al), and residual iron (Fe). Therefore, the nodular graphite cast iron is able to have a thinner surface oxidation layer, and is able to have improved dial division per minute (ddpm).