STEEL AND STAINLESS STEEL WITH TWO-PHASE STRUCTURE OF AUSTENITE AND MARTENSITE

摘要

The present invention relates to steel and stainless steel consisting of austenite and martensite having a face-centered cubic (FCC) crystal structure at a room temperature such as 304, 304L, 316, 316L, 309, 310 and 202 having excellent machinability and corrosion resistance to be widely used in various industrial fields. More specifically, the steel and stainless steel with a two-phase structure of austenite and martensite comprise Mn, Cr, one or more among Co, Ni, Si, Al, and Ti, and the remainder consisting of Fe or comprise C, Cr, Mn, Si, Co, Al, Ni, and the remainder consisting of Fe. In the steel with the two-phase structure where austenite and martensite exist together, strength and a damping capacity are changed by a volume fraction and transformation behavior of the structure. Therefore, two-phase steel with an excellent combination of strength and a damping capacity can be manufactured by a method of having different check fractions of austenite and martensite by machining, reverse transformation annealing after machining, and a thermo-mechanical treatment performing machining and reverse transformation annealing after machining in parallel in steel with an austenite structure. Also, when the two-phase steel with an excellent combination of strength and a damping capacity is used to make various structures, apparatuses, devices, and home appliances, an amount of material used can be reduced. Absorbency of vibration and noise is excellent to secure a long service life, maturity, and precision.;COPYRIGHT KIPO 2017