FERRITIC STAINLESS STEEL FOR BIOFUEL SUPPLY SYSTEM PART, BIOFUEL SUPPLY SYSTEM PART, FERRITIC STAINLESS STEEL FOR EXHAUST HEAT RECOVERY UNIT, AND EXHAUST HEAT RECOVERY UNIT

• Main Authors: FUDANOKI FUMIO, HIRAIDE NOBUHIKO, SAKAMOTO SHUNJI
• Format: Patent
• Language: English; French; Japanese
• Published: 04.10.2012
• Subjects: ALLOYS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TREATMENT OF ALLOYS OR NON-FERROUS METALS

According to one embodiment, ferritic stainless steel comprises, by mass%, 0.03% or less of C, 0.03% or less of N, more than 0.1% but 1% or less of Si, between 0.02% and 1.2% of Mn, between 15% and 23% of Cr, between 0.002% and 0.5% of Al, and one or both of Nb and Ti, with the balance being Fe and inevitable impurities; formulas (1) and (2) are satisfied; and an oxide film comprising 30% or more of Cr, Si, Nb, Ti, and Al in terms of the total cation percentage is formed on the surface. 8(C+N)+0.03=Nb+Ti=0.6 ...(1) Si+Cr+Al+{Nb+Ti-8(C+N)}=15.5 ...(2) D'après un mode de réalisation, un acier inoxydable ferritique contient, en % en masse, 0,03 % ou moins de C, 0,03 % ou moins de N, de 0,1 % (limite non comprise) à 1 % (limite comprise) de Si, entre 0,02 % et 1,2 % de Mn, entre 15 % et 23 % de Cr, entre 0,002 % et 0,5 % d'Al et du Nb et/ou du Ti, le reste étant constitué de Fe et des inévitables impuretés. Les formules (1) et (2) sont satisfaites. Il est formé sur la surface un film d'oxyde contenant au moins 30 % de Cr, Si, Nb, Ti et Al en termes de pourcentage total de cations. 8(C+N)+0.03=Nb+Ti=0.6 ...(1) Si+Cr+Al+{Nb+Ti-8(C+N)}=15.5 ...(2)