Steel plate having excellent acid dew point corrosion resistance, method of production, and exhaust gas channel constituent member

摘要

[Problem] To simultaneously and significantly improve the sulfuric acid dew point corrosion resistance and hydrochloric acid dew point corrosion resistance in steel based on ordinary steel. [Solution] Provided is a steel plate having excellent acid dew point corrosion resistance, which has a chemical composition, in mass%, of C: 0.001% to 0.15%; Si: 0.80% or less; Mn: 1.50% or less; P: 0.025% or less; S: 0.030% or less; Cu: 0.10% to 1.00%; Ni: 0.50% or less; Cr: 0.05% to 0.25%; Mo: 0.01% to 0.08%; Al: 0.100% or less; Ti, Nb, V: total 0% to 0.20%; B: 0% to 0.010%; and Sb, Sn: total 0% to 0.10%, with a remainder of Fe and inevitable impurities, and contains a ferrite single-phase structure, or one or more types of cementite, pearlite, bainite, and martensite in the range of a total of 30 vol% or less, the remainder having a structure that is a ferrite phase, and the mean grain size of the ferrite crystal grains being 12.0 μm or less.