STAINLESS STEEL AND MATERIAL TREATMENT METHOD

• Main Authors: NOJIMA MASAFUMI, MARUNO YUSAKU, KOMURO MATAHIRO, KONDO YASUO, AONO YASUHISA
• Format: Patent
• Language: English; Japanese
• Published: 19.05.2016
• 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 improve the mechanical properties and corrosion resistance of stainless steel and also to reduce its residual stress.SOLUTION: In Fe based stainless steel containing Cr by 15% or more, modulated compositions in which a layered Fe-rich phase and a layered Cr-rich phase are mutually formed are at a plurality of parts along at least a part of the boundaries of the crystal grains of α phases. The material treatment method comprises: a heating step where a rolled stainless steel is heated, and its temperature is increased to a temperature of the Curie point of the stainless steel; a cooling step where the stainless steel is cooled from the temperature less than the Curie point; and a magnetic field application step where magnetic fields are applied to the rolling direction of the stainless steel over the range between the temperature less than the Curie point from the prescribed temperature in the heating step and the other prescribed temperature from the Curie point or lower in the cooling step.SELECTED DRAWING: Figure 8 【課題】 ステンレス鋼の機械的性質と耐食性を向上させかつ残留応力を低減する。【解決手段】 Crを15％以上含有するFe系ステンレス鋼において、層状のFeリッチ相と層状のCrリッチ相とが交互に形成された変調組成部がα相の結晶粒の少なくとも一部の粒界に沿って複数箇所形成されている。圧延されたステンレス鋼を加熱し前記ステンレス鋼のキュリー点以下の温度まで昇温する加熱工程と、前記ステンレス鋼を前記キュリー点以下の温度から冷却する冷却工程と、前記加熱工程における所定の温度から前記キュリー点以下の温度と、前記冷却工程における前記キュリー点以下の温度から他の所定の温度との範囲にわたって、前記ステンレス鋼の圧延方向に磁場を印加する磁場印加工程とを備えることを特徴とする材料処理方法。【選択図】図８