抄録
Through the chemical analysis of the environment of smoke stacks and down-hole for thermal power plants, it was clarified that sulfuric acid dew point environment was the one where there were much amount of Cl- and Fe3+ with the range of 10-1000ppm besides H2SO4. Then, effect of Cl- and Fe3+ and alloying contents (Cr, Ni, Mo, Cu and N) on corrosion behavior of various stainless steels in H2SO4 environment were studied by immersion test and polarization curve measurements. By analyzing these data, corrosion rate of stainless steels in 50mass% H2SO4 with 1000ppm Cl- and Fe3+ can be expressed as the following general corrosion resistance index (GI); GI=-[Cr]+3.6[Ni]+4.7[Mo]+11.5[Cu].
