High-silicon ferritic heat-resistant cast iron having high-temperature strength and high oxidation resistance

Abstract

Disclosed are a ferritic heat-resistant cast iron comprising 5.0˜7.0 weight % of Silicon (Si) to improve oxidation resistance of the cast iron and a method for preparing the same.

1 . A high-silicon ferritic heat-resistant cast iron having improved high-temperature strength and oxidation resistance comprising: 2.5˜3.8 weight % of C, 5.0˜7.0 weight % of Si, 0.2˜0.8 weight % of Mn, 0.05 weight % or less of P, 0.02 weight % of less of S, 0.5˜1.2 weight % of Mo, 0.1 weight % or less of Ni, 0.5 weight % or less of V, 0.01˜0.1 weight % of Cr, 0.05 weight % or less of Sb, and the balance of Fe. 
     
     
         2 . A method for preparing a high-silicon ferritic heat-resistant cast iron having an excellent high-temperature strength and a high oxidation resistance; comprising the steps of:
 (a) casting an iron alloy material comprising 2.5˜3.8 weight % of C, 5.0˜7.0 weight % of Si, 0.2˜0.8 weight % of Mn, 0.05 weight % or less of P, 0.02 weight % of less of S, 0.5˜1.2 weight % of Mo, 0.1 weight % or less of Ni, 0.5 weight % or less of V, 0.01˜0.1 weight % of Cr, 0.05 weight % or less of Sb, and the balance of Fe; and   (b) annealing the cast iron in a manner that the temperature is raised up to 960° C. at a rate of 20° C./min, the raised temperature is kept for 20 minutes and them slowly cooled down to 400° C. at a rate of 20° C./min.   
     
     
         3 . A motor vehicle comprising the cast iron of  claim 1 . 
     
     
         4 . A motor vehicle comprising a part made by the method of  claim 2 .