Cast iron material

Abstract

Provided is a cast iron material from which excellent friction characteristics can be obtained. Provided is the cast iron material containing C and Fe as a composition, and further containing Cr as the composition in 1.0 to 3.5% in terms of mass %. The cast iron material is used in a sliding component sliding under an environment of lubricating oil to which an additive containing Mo as a constituent element, such as MoDTC, is added. Cr contained in the cast iron material promotes a decomposition reaction of the additive containing Mo added to the lubricating oil to form a film of molybdenum disulfide, the film having low friction. Thus, the fiction can be reduced.

1 . A cast iron material, comprising:
 carbon (C) and iron (Fe) as a composition; and   chromium (Cr) as the composition in 1.0 to 3.5% in terms of mass %; and   including graphite as a structure, wherein   the cast iron material is used in a sliding component sliding under an environment of lubricating oil containing molybdenum (Mo) as an additive.   
     
     
         2 . The cast iron material according to  claim 1 , comprising at least silicon (Si) from the group consisting of silicon (Si), copper (Cu) and nickel (Ni) as the composition, wherein a content thereof is from 2 to 6.5% of Si, from 0 to 1.5% of Cu, and from 0 to 1.5% of Ni in terms of mass %. 
     
     
         3 . The cast iron material according to  claim 1 , wherein Brinell hardness is from HB200 to HB380. 
     
     
         4 . The cast iron material according to  claim 1 , wherein a film containing molybdenum disulfide is formed on a surface by sliding. 
     
     
         5 . The cast iron material according to  claim 1 , wherein the cast iron material is used in a sliding portion of an engine part and a driving part.