EXTREMELY LOW CARBON-BASED ACID-PROOF DEW POINT CORROSION STEEL HAVING EXCELLENT INTERGRANULAR FRACTURE RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a steel which exhibits satisfactory corrosion resistance in an acid dew point corrosive environment while maintaining high workability by preventing intergranular fracture on working.;SOLUTION: The extra-low carbon-based acid-proof dew point corrosion steel has a composition comprising, by mass, ≤0.0100% C, 0.1 to 2.0% Si, ≤1.0% Mn, ≤0.05% P, ≤0.05% S, 0.05 to 1.0% Cu, ≤0.10% Al, ≤0.020% N and 0.0005 to 0.0050% B, and the balance Fe with subordinate components and/or inevitable impurities, and has a structure essentially consisting of ferrite with a mean crystal grain size of ≤100 μm. The content of C is desirably controlled to ≤0.0050%. If required, one or more kinds of metals selected from ≤1.0% Cr, ≤1.0% Mo, ≤0.5% Ni, ≤0.1% Nb, ≤0.1% V, ≤0.1% Ti and 0.01 to 0.2% Sn are incorporated therein.;COPYRIGHT: (C)2005,JPO&NCIPI