FERRITIC STAINLESS STEEL SHEET HAVING EXCELLENT HEAT RESISTANCE

• Main Authors: FUKUDA, Akihiro, KOBAYASHI, Masaaki, TERAOKA, Shinichi
• Format: Patent
• Language: English; French; German
• Published: 04.03.2020
• Subjects: ALLOYS; BLASTING; CHEMISTRY; ENGINE PLANTS IN GENERAL; FERROUS OR NON-FERROUS ALLOYS; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; MECHANICAL ENGINEERING; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; STEAM ENGINES; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WEAPONS

The present invention provides a Sn-containing ferritic stainless steel sheet having excellent heat resistance. The ferritic stainless steel contains, in terms of mass %, 0.015% or less of C, 1.5% or less of Si, 1.5% or less of Mn, 0.035% or less of P, 0.015% or less of S, 13-21% of Cr, 0.01-0.50% of Sn, 0.05-0.60% of Nb and 0.020% or less of N, with the remainder consisting of Fe and unavoidable impurities. The ferritic stainless steel satisfies formula 1 and formula 2, and has a grain boundary Sn concentration of 2 atom % or less when subjected to a heat treatment at 600-750°C in which the value of L, as shown in formula 3, is 1.91×10 4 or higher. 8 ‰¤ CI = (Ti+0.52Nb) / (C+N) ‰¤ 26 (formula 1) GBSV = Sn+Ti-2Nb-0.3Mo-0.2 ‰¤ 0 (formula 2) L = (273+T) (log(t)+20) (formula 3) T: Temperature (°C), t: time (h)