Austenitic steel having excellent surface characteristics, and method of manufacturing the same

Abstract

The present disclosure relates to an austenitic steel having excellent surface characteristic, and a method of manufacturing the same. Provided are an austenitic steel having excellent surface characteristic, and a method for producing the same, the austenitic steel according to an aspect of the present disclosure comprising, by weight, carbon (C): 0.6% to 1.3%, manganese (Mn): 14% to 22%, copper (Cu): 5% or less (excluding 0%), chromium (Cr): 5% or less (excluding 0%), silicon (Si): 1.0% or less (excluding 0%), aluminum (Al): 0.5% or less (excluding 0%), phosphorus (P): 0.1% or less (including 0%), sulfur (S): 0.02% or less (including 0%), a remainder of iron (Fe), and inevitable impurities, wherein a microstructure of the austenitic steel comprises, by area, 5% or less of carbide and a remaining austenite structure, and a surface defect size of the austenitic steel is 0.3 mm or less.

1 . An austenitic steel having excellent surface characteristics, comprising, by weight, carbon (C): 0.6% to 1.3%, manganese (Mn): 14% to 22%, copper (Cu): 5% or less (excluding 0%), chromium (Cr): 5% or less (excluding 0%), silicon (Si): 1.0% or less (excluding 0%), aluminum (Al): 0.5% or less (excluding 0%), phosphorus (P): 0.1% or less (including 0%), sulfur (S): 0.02% or less (including 0%), a remainder of iron (Fe), and inevitable impurities,
 wherein a microstructure of the austenitic steel comprises, by area, 5% or less of carbide and a remaining austenite structure, and   a surface defect size of the austenitic steel is 0.3 mm or less.   
     
     
         2 . The austenitic steel according to  claim 1 , wherein the surface defect size of 0.2 mm or less. 
     
     
         3 . A method of manufacturing an austenitic steel having excellent surface characteristics, comprising:
 reheating a slab to a temperature of 1000° C. or higher to 1150° C. or lower, the slab comprising, by weight, carbon (C): 0.6% to 1.3%, manganese (Mn): 14% to 22%, copper (Cu): 5% or less (excluding 0%), chromium (Cr): 5% or less (excluding 0%), silicon (Si): 1.0% or less (excluding 0%), aluminum (Al): 0.5% or less (excluding 0%), phosphorus (P): 0.1% or less (including 0%), sulfur (S): 0.02% or less (including 0%), a remainder of iron (Fe), and inevitable impurities;   hot-rolling the reheated slab at a finishing rolling temperature of 850° C. to 950° C. to obtain a hot-rolled steel; and   cooling the hot-rolled steel to a temperature of 600° C. or lower at a cooling rate of 5° C./s or higher.   
     
     
         4 . The method according to  claim 3 , wherein the cooling rate in the cooling is 15° C./s or higher. 
     
     
         5 . The method according to  claim 3 , wherein a microstructure of the austenitic steel comprises, by area, 5% or less of carbide and a remaining austenite structure, and
 a surface defect size of the austenitic steel is 0.3 mm or less.