AUSTENITIC STAINLESS STEEL SHEET HAVING LESS SURFACE COLOR UNEVENNESS, METHOD FOR MANUFACTURING THE SAME, AND EXHAUST PART

• Main Authors: MATSUHASHI TORU, YOSHII MUTSUKO, OYAMA RYOHEI, HAMADA JUNICHI
• Format: Patent
• Language: English; Japanese
• Published: 16.09.2021
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METALLURGY; PERFORMING OPERATIONS; PUNCHING METAL; ROLLING OF METAL; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS

To provide a method for manufacturing a high Si containing austenitic stainless steel sheet, capable of reducing surface color unevenness even when omitting a grinding/polishing step after intermediate cold-rolling, annealing and acid cleaning steps, and a high Si containing austenitic stainless steel sheet capable of suppressing the melt-down of molten metal relevant to surface unevenness and the deterioration of high temperature salt damage resistance.SOLUTION: An austenitic stainless steel sheet includes Si of 0.5-4.0% by mass%. An acid cleaned, cold-rolled and annealed steel sheet has a difference Δ*between the maximum and minimum of a surface color difference index L* satisfying Δ*≤0.50 and can suppress the deterioration of high temperature salt damage resistance. A method for manufacturing the austenitic stainless steel sheet includes performing cold-rolling, annealing, and acid cleaning n times, and the roughness of a roller used for the finish cold-rolling of each cold-rolling up to (n-1)th is Ra≤0.5 μm.SELECTED DRAWING: None 【課題】中間冷延・焼鈍・酸洗後の研削／研磨工程を省略した場合であっても、表面色ムラを低減できる高Ｓｉ含有オーステナイト系ステンレス鋼板の製造方法を提供すること、表面ムラに関連する溶接金属の溶け落ちが抑制され、耐高温塩害性の劣化が抑制される高Ｓｉ含有オーステナイト系ステンレス鋼板を提供すること。【解決手段】質量％で、Ｓｉ：０．５〜４．０％含有するオーステナイト系ステンレス薄鋼板であって、酸洗された冷延焼鈍鋼板における、表面の色差指標L*の最大値と最小値の差ΔL*がΔL*≦０．５０であり、耐高温塩害性の劣化が抑制されることを特徴とするオーステナイト系ステンレス鋼板。冷間圧延、焼鈍、酸洗をｎ回実施する鋼鈑の製造方法において、（ｎ−１）回目までの各冷間圧延の仕上げ冷延に使用するロール粗度をＲａ≦０．５μｍとすることを特徴とする上記オーステナイト系ステンレス鋼板の製造方法。【選択図】なし