Ferritic stainless steel and method for producing same, and heat exchanger equipped with ferritic stainless steel as member

• Main Authors: TAMURA YUUICHI, MATSUHASHI TOORU
• Format: Patent
• Language: Chinese; English
• Published: 22.03.2017
• Subjects: ALLOYS; CHEMISTRY; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MACHINE TOOLS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; PERFORMING OPERATIONS; SOLDERING OR UNSOLDERING; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WELDING; WORKING BY LASER BEAM

Provided are: a ferritic stainless steel which can exhibit excellent heat exchange properties, corrosion resistance and brazing properties when used as a member of a heat exchanger; and a heat exchanger which is manufactured using the ferritic stainless steel. The ferritic stainless steel contains, in % by mass, 0.030% or less of C, 0.020% or less of N, 0.5% or less of Si, 1.0% or less of Mn, 0.05% or less of P, 0.01% or less of S, 16 to 25% of Cr, 0.05 to 1.0% of Nb and 0.003 to 0.20% of Al, wherein an Al oxide exists on the material surface, the surface coverage ratio is 5 to 70%, the surface roughness (Ra) is 0.010 to 0.15 [mu]m as measured with a red laser, and the thickness, which is expressed in a half value of Al obtained from an elemental profile that is expressed in cationic ratios, from the surface satisfies 300 nm or less. 本发明提供热交换器用构件的热交换特性、耐蚀性和焊接性优异的铁素体系不锈钢和使用了该不锈钢的热交换器。上述铁素体系不锈钢是以质量％计包含C：0.030％以下、N：0.020％以下、Si：0.5％以下、Mn：1.0％以下、P：0.05％以下、S：0.01％以下、Cr：16～25％、Nb：0.05～1.0％、Al：0.003～0.20％的铁素体系不锈钢，在该材