Acid dew point corrosion-resistant steel and exhaust gas flow path constituent member

Abstract

A steel has improved sulfuric acid dew point corrosion resistance without relying upon the addition of Sb and can have improved hydrochloric acid dew point corrosion resistance. The acid dew point corrosion-resistant steel includes from 0.005 to 0.200% of C, from 0.20 to 0.80% of Si, from 0.05 to 1.50% of Mn, from 0.002 to 0.020% of P, from 0.005 to 0.015% of S, from 0.10 to 0.50% of Cu, from 0.05 to 0.30% of Ni, from 0.005 to 0.100% of Al, and 0 or more and less than 0.010% of Mo in terms of % by mass, with the balance being Fe and impurities. In the case of attaching great importance to hydrochloric acid dew point corrosion resistance, it is desirable to control the Mo content in the foregoing steel to from 0.005 to 0.030% by mass.

1 . An acid dew point corrosion-resistant steel comprising from 0.005 to 0.200% of C, from 0.20 to 0.80% of Si, from 0.05 to 1.50% of Mn, from 0.002 to 0.020% of P, from 0.005 to 0.015% of S, from 0.10 to 0.50% of Cu, from 0.05 to 0.30% of Ni, from 0.005 to 0.100% of Al, and 0 or more and less than 0.010% of Mo in terms of % by mass, with the balance being Fe and impurities. 
     
     
         2 . The acid dew point corrosion-resistant steel according to  claim 1 , wherein the content of Mo is from 0.005 to 0.030%. 
     
     
         3 . An exhaust gas flow path constituent member that is a member using a steel plate comprising the steel according to  claim 1  and which in a flow path of a combustion exhaust gas in a coal-burning thermal power plant, constitutes a site at which condensation is generated on a surface thereof upon being exposed to the exhaust gas.