/ CORROSION RESISTANT STEEL HAVING HIGH RESISTANCE TO CORROSION AT SULFURIC AND SULFURIC/HYDROCHLORIC ACID CONDENSING ENVIRONMENT AND MANUFACTURING METHOD THE SAME

摘要

The present invention relates to a steel sheet having corrosion resistance in a sulfuric acid and sulfuric acid/hydrochloric acid complex environment, and a method of manufacturing the same. Corrosion-resistant steel sheet according to an embodiment of the present invention, by weight %, carbon (C): 0.15% or less (excluding 0%), copper (Cu): 0.05 to 0.5%, nickel (Ni): 0.02 to 0.3 %, antimony (Sb): 0.05 to 0.45%, and tin (Sn): 0.05 to 0.45%, contains the balance iron (Fe) and inevitable impurities, and satisfies the following formula (1) When immersed in 50wt% sulfuric acid solution for 6 hours, a concentrated layer of sulfuric acid immersion is formed from the surface of the steel sheet in the inner direction, and the steel sheet is immersed in a solution of 16.9 vol% sulfuric acid solution and 0.35 vol% hydrochloric acid solution for 24 hours. , A composite immersion thickening layer is formed in the inner direction from the surface of the steel sheet, and the thickness of the sulfuric acid immersion thickening layer and the composite immersion thickening layer is 360 to 500 nm, respectively. [Equation 1] 1 Cu + 3ｘSb + 5ｘSn + 5ｘW + Mo ≤ 1.15 (wt%)