POSCO Holdings Inc.
FERRITIC STAINLESS STEEL HAVING REDUCED CARBON SLUDGE ADSORPTION FOR EXHAUST SYSTEM HEAT EXCHANGER AND METHOD OF MANUFACTURING SAME

Abstract:

Provided is a ferritic stainless steel for an exhaust system heat exchanger and a method of manufacturing the same. The ferritic stainless steel includes, in percent (%) by weight of the entire composition, 0.003 to 0.1% of carbon (C), 0.01 to 2.0% of silicon (Si), 0.01 to 1.5% of manganese (Mn), 0.05% or less of phosphorus (P), 0.005% or less of sulfur (S), 10 to 30% of chromium (Cr), 0.001 to 0.10% of titanium (Ti), 0.001 to 0.15% of aluminum (Al), 0.003 to 0.03% of nitrogen (N), 0.3 to 0.6% of niobium (Nb), 0.01 to 2.5% of molybdenum (Mo), and the remainder of iron (Fe) and other inevitable impurities, wherein TiN precipitates having a size of 0.1 .mu.m or more are distributed in a surface layer of a ferrite matrix at a concentration of 2.5*10.sup.4 ea/mm.sup.2 or less.