HIGH Mn AUSTENITIC STAINLESS STEEL AND METHOD FOR PRODUCING THE SAME

• Main Author: HIRATA SHIGERU
• Format: Patent
• Language: English; Japanese
• Published: 20.11.2014
• 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

PROBLEM TO BE SOLVED: To provide a high Mn austenitic stainless steel having excellent settling resistance, and in which the deposition and peeling of scale are hard to occur, and a method for producing the same.SOLUTION: A steel stock having a composition comprising, by mass, 0.03 to 0.12% of C, 0.5 to 2.0% of Si, 10 to 25% of Mn, 0.035% or less of P, 0.001% or less of S, 1.2 to 7% of Ni, 14 to 25% of Cr, 0.05 to 1.0% of Cu, 0.25 to 0.50% of N, 0.05% or less of Al and 0.03 to 0.5% of V, and also comprising one or two kinds selected from Mo and W in the range of 0.5 to 4% in total, and in which Ni equivalent(=Ni+0.38Mn+22C+13N+0.43Cu-0.077Cr-0.5Si-0.14(Mo+W)-1.5V) is 14.0% or more is subjected to hot rolling, primary cold rolling, process annealing, secondary cold rolling at a draft of 20% or more, and aging treatment at 300 to 600°C. 【課題】耐へたり性に優れ、スケールの溶着や剥離を起こし難い、高Ｍｎオーステナイト系ステンレス鋼を提供するとともに、その製造方法を提案する。【解決手段】ｍａｓｓ％で、Ｃ：０．０３〜０．１２％、Ｓｉ：０．５〜２．０％、Ｍｎ：１０〜２５％、Ｐ：０．０３５％以下、Ｓ：０．００１％以下、Ｎｉ：１．２〜７％、Ｃｒ：１４〜２５％、Ｃｕ：０．０５〜１．０％、Ｎ：０．２５〜０．５０％、Ａｌ：０．０５％以下およびＶ：０．０３〜０．５％を含有し、かつ、ＭｏおよびＷのうちから選ばれる１種または２種を合計で０．５〜４％の範囲で含有し、Ｎｉ当量（＝Ｎｉ＋０．３８Ｍｎ＋２２Ｃ＋１３Ｎ＋０．４３Ｃｕ−０．０７７Ｃｒ−０．５Ｓｉ−０．１４（Ｍｏ＋Ｗ）−１．５Ｖ）が１４．０％以上である鋼素材を熱間圧延し、一次冷間圧延し、中間焼鈍し、圧下率２０％以上の二次冷間圧延し、３００〜６００℃で時効処理を施す。【選択図】図２