Austenitic stainless steel product having excellent surface properties and manufacturing method of the same

A method of manufacturing an austenitic stainless steel product, the method comprising:

• processing the austenitic stainless steel product, comprising:
• by weight percent, 0.005 to 0.15% of C, 0.1 to 1.0% of Si, 0.1 to 2.0% of Mn, 6.0 to 8.0% of Ni, 16 to 18% of Cr, 0.1 to 4.0% of Cu, 0.005 to 0.2% of N, 0.01 to 0.2% of Mo, and the remainder comprising iron (Fe) and other unavoidable impurities;
• and
• heat treating the austenitic stainless steel product at a temperature of 900-1,150° C. for 10 minutes or less;
• and
• cooling the heat-treated austenitic stainless steel to 500° C. within 30 minutes;
• wherein the austenitic stainless steel product has a surface degree of negative segregation of Ni defined by the following formula (1) is in the range of 0.6 to 0.9 and the martensite fraction thereof is 10 to 30%
• (CNi-Min)/(CNi-Ave) Formula (1)
• Where CNi-Min is the minimum concentration of Ni at the surface and CNi-Ave is the average concentration of Ni at the surface, and
• wherein a surface hardness ratio defined by the following formula (2) is in the range of 1.1 to 1.6
• A/B Formula (2)
• where A is the average value of the upper 10% of the product surface hardness, and B is the average value of the lower 10% the product surface hardness.