High manganese steel sheet having excellent damping property, and manufacturing method therefor

Abstract

Provided is a high Mn steel sheet and a manufacturing method therefor, the steel sheet comprising, by wt %: 0-0.1% or less of C; 8-30% of Mn; 0.1% or less of P; 0.02% or less of S; 0.10 or less of N; 0-1.00 of Ti; and Fe and inevitable impurities, wherein a microstructure has epsilon martensite and austenite, and the average particle diameter of the martensite and the austenite is 2 μm or less.

1 . A high Mn steel sheet having excellent damping properties, comprising
 0.1 wt % or less of carbon (C), 8 wt % to 30 wt % of manganese (Mn), 0.1 wt % or less of phosphorus (P), 0.02 wt % or less of sulfur (S), 0.1 wt % or less of nitrogen (N), 0 wt % to 1.0 wt % of titanium (Ti), and iron (Fe) and inevitable impurities,   wherein a microstructure contains epsilon martensite and austenite, and an average particle diameter of each of the martensite and the austenite is 2 μm or less.   
     
     
         2 . The high Mn steel sheet having excellent damping properties of  claim 1 , wherein the steel sheet additionally comprises one, two, or more among 0 wt % to 3 wt % of silicon (Si), 0.005 wt % to 5.0 wt % of chromium (Cr), 0.005 wt % to 2.0 wt % of nickel (Ni), 0.005 wt % to 0.5 wt % of niobium (Nb), 0.0001 wt % to 0.01 wt % of boron (B), 0.005 wt % to 0.5 wt % of vanadium (V), and 0.005 wt % to 1 wt % of tungsten (W). 
     
     
         3 . The high Mn steel sheet having excellent damping properties of  claim 1 , wherein a room temperature specific damping capacity (SDC) value of the steel sheet is 0.00015 or more. 
     
     
         4 . A method for manufacturing a high Mn steel sheet having excellent damping properties, comprising:
 heating a high Mn steel sheet, including 0 wt % to 0.1 wt % or less of carbon (C), 8 wt % to 30 wt % of manganese (Mn), 0.1 wt % or less of phosphorus (P), 0.02 wt % or less of sulfur (S), 0.1 wt % or less of nitrogen (N), 0 wt % to 1.0 wt % of titanium (Ti), andiron (Fe) and inevitable impurities to a heat treatment temperature of Ac1° C. to Ac3+50° C. at a heating rate of 0.01° C./s to 200° C./s;   maintaining the high Mn steel sheet for 0.01 second to 24 hours at the heat treatment temperature; and   cooling the high Mn steel sheet to room temperature at a cooling rate of 0.01° C./s or more.   
     
     
         5 . The method for manufacturing high Mn steel sheet having excellent damping properties of  claim 4 , wherein a microstructure of the high Mn steel sheet has epsilon martensite and austenite. 
     
     
         6 . The method for manufacturing high Mn steel sheet having excellent damping properties of  claim 4 , wherein the steel sheet additionally comprises one, two, or more among 0 wt % to 3 wt % of silicon (Si), 0.005 wt % to 5.0 wt % of chromium (Cr), 0.005 wt % to 2.0 wt % of nickel (Ni), 0.005 wt % to 0.5 wt % of niobium (Nb), 0.0001 wt % to 0.01 wt % of boron (B), 0.005 wt % to 0.5 wt % of vanadium (V), and 0.005 wt % to 1 wt % of tungsten (W).