Hot rolled steel sheet excellent in sulfuric acid and hydrochloric acid composite corrosion resistance and method for manufacturing the same

摘要

Disclosed are: a hot-rolled steel sheet having excellent composite resistance to sulfuric acid and hydrochloric acid; and a manufacturing method therefor. An aspect of the present invention provides a hot-rolled steel sheet having excellent composite corrosion resistance to sulfuric acid and hydrochloric acid, the hot-rolled steel sheet containing, by weight%, 0.05-0.1% of C, 0.5-1.5% of Mn, 0.02% or less of P, 0.02% or less of S, 0.01-0.1% of Al, 0.2-0.6% of Cu, 0.05-0.1% of Sb, the remainder Fe, and inevitable impurities, wherein Cu and Sb are enriched within 500 nm from the surface in the thickness direction, and the mass loss to a solution of 16.9 vol% of sulfuric acid + 0.35 vol% of hydrochloric acid is 2.0 mg/cm2/hr.