Heat resistant spheroidal graphite cast iron, method of manufacturing the same and engine exhaust system part including the same

A method of manufacturing heat resistant spheroidal graphite cast iron, comprising:

• forming a molten cast iron including carbon (C) in a range from about 3.2 weight percent to about 3.4 weight percent, silicon (Si) in a range from about 4.3 weight percent to about 4.8 weight percent, manganese (Mn) in a range from about 0.2 weight percent to about 0.3 weight percent, molybdenum (Mo) in a range from about 0.8 weight percent to about 1.0 weight percent, vanadium (V) in a range from about 0.4 weight percent to about 0.6 weight percent, chrome (Cr) in a range from about 0.2 weight percent to about 0.4 weight percent, niobium (Nb) in a range from about 0.2 weight percent to about 0.4 weight percent, inevitable impurities, and a remainder of iron (Fe), based on a total weight;
• tapping the molten cast iron into a ladle;
• and
• injecting the tapped molten cast iron into a mold
• wherein, prior to injecting the tapped molten cast iron into the mold, barium (Ba) is added into the molten cast iron in a range from about 0.0045 weight percent to about 0.0075 weight percent, and a content ratio of chrome (Cr) and barium (Ba) (Cr/Ba) is in a range from about 26 to 89.