Steel and air preheater with excellent resistance to sulfuric acid dew point corrosion

摘要

A steel excellent in the resistance to sulfuric acid dew point corrosion, which has a chemical composition, in mass %: C:/=0.20 %, Si: 1.2 to 3.5 %, Cu: 0.05 to 1.0 %, Sb: 0.03 to 0.30 %, Mn: /= 1.0 %, P: /= 0.05 %, S: /= 0.05 %, Al: /= 0.10 %, balance: Fe and following components and/or inevitable impurities; and the steel which further comprises one or more of the followings: Cr: /= 1.0 %, Mo: /= 1.0 %, Ni: /= 0.5 %, Nb: /= 0.1 %, V: /= 0.1 %, Ti: /= 0.1 %, Sn: 0.01 to 0.2 %, B: 0.0005 to 0.010 %; and a preheater for air using the steel in its heat transfer element. The steel exhibits excellent resistance to sulfuric acid dew point corrosion over the whole range of temperature from high to low.