Al-CONTAINING FERRITIC STAINLESS STEEL SHEET AND METHOD FOR PRODUCING THE SAME

• Main Authors: IMAGAWA KAZUNARI, FUJIMURA YOSHIYUKI, HAMADA TAKAHITO
• Format: Patent
• Language: English; Japanese
• Published: 20.08.2020
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

To provide an Al-containing ferritic stainless steel sheet that is excellent in high temperature oxidation resistance as well as that has a good creep property even when the sheet thickness is reduced.SOLUTION: Provided is an Al-containing ferritic stainless steel sheet having a composition containing C: 0.025 mass% or less, Si: 0.1 to 1.0 mass%, Mn: 1.0 mass% or less, P: 0.05 mass% or less, S: 0.01 mass% or less, Ni: 0.6 mass% or less, Cr: 16 to 22 mass%, Nb: 0.05 to 0.50 mass%, Al: 1.0 to 2.4 mass%, N: 0.025 mass% or less, and B: 0.0005 to 0.0060 mass%, and the balance being Fe and inevitable impurities. This Al-containing ferritic stainless steel sheet has an average crystal grain size in the sheet thickness direction of 25 to 90 μm, and the grain boundary coverage rate by the precipitates present at the crystal grain boundary is 5% or more.SELECTED DRAWING: None 【課題】高温酸化性に優れると共に、板厚を小さくしてもクリープ特性が良好なＡｌ含有フェライト系ステンレス鋼板を提供する。【解決手段】Ｃ：０．０２５質量％以下、Ｓｉ：０．１〜１．０質量％、Ｍｎ：１．０質量％以下、Ｐ：０．０５質量％以下、Ｓ：０．０１質量％以下、Ｎｉ：０．６質量％以下、Ｃｒ：１６〜２２質量％、Ｎｂ：０．０５〜０．５０質量％、Ａｌ：１．０〜２．４質量％、Ｎ：０．０２５質量％以下、Ｂ：０．０００５〜０．００６０質量％を含有し、残部がＦｅ及び不可避的不純物からなる組成を有するＡｌ含有フェライト系ステンレス鋼板である。このＡｌ含有フェライト系ステンレス鋼板は、板厚方向の平均結晶粒径が２５〜９０μｍであり、且つ結晶粒界に存在する析出物の粒界被覆率が５％以上である。【選択図】なし