Austenitic stainless steel having a large amount of unifromly distributed nanometer-sized precipitates and preparing method of the same

Austenitic stainless steel comprising

• 16 to 26 wt % of chromium (Cr), 8 to 22 wt % of nickel (Ni), 0.02 to 0.1 wt % of carbon (C), 0.2 to 1 wt % of niobium (Nb), and 2 to 3.5 wt % of manganese (Mn),
• and including an austenite matrix, wherein
• a niobium carbide (NbC) is precipitated in the austenite matrix, and
• the niobium carbide is uniformly dispersed in the austenite matrix,
• wherein an average diameter of the niobium carbide is equal to or less than 11 nm, and
• wherein the austenitic stainless steel is a forged multi-pass hot rolled stainless steel.