High-strength austenitic stainless steel with excellent hot workability

Abstract

Disclosed is a high-strength austenitic stainless steel having excellent hot workability. The high-strength austenitic stainless steel having excellent hot workability according to the present disclosure includes, in percent by weight (wt %), 0.01 to 0.035% of C, 0.5% or less of Si, 0.5 to 1.5% of Mn, 17 to 22% of Cr, 6 to 11% of Ni, 1% or less of Mo, 1% or less of Cu, 0.1 to 0.22% of N, and the balance of Fe and inevitable impurities, wherein a value of Formula (1) below 1.9 or more, or a precipitation temperature of chromium nitride satisfies a value represented by Formula (2) below or less. 3×(Cr+Mo)+5×Si−2×Ni−Mn−70×(C+N)−27  (1) 1180+36×C+12×Mo+17×Cu+411×N−35×Mn  (2)

1 . A high-strength austenitic stainless steel having excellent hot workability comprising, in percent by weight (wt %), 0.01 to 0.035% of C, 0.5% or less of Si, 0.5 to 1.5% of Mn, 17 to 22% of Cr, 6 to 11% of Ni, 1% or less of Mo, 1% or less of Cu, 0.1 to 0.22% of N, and the balance of Fe and inevitable impurities,
 wherein a value of Formula (1) below 1.9 or more, or a precipitation temperature of a chromium nitride satisfies a value represented by Formula (2) below or less:
   3×(Cr+Mo)+5×Si−2×Ni−Mn−70×(C+N)−27  (1)
 
   1180+36×C+12×Mo+17×Cu+411×N−35×Mn  (2)
 
   (wherein Cr, Mo, Si, Ni, Mn, C, N, and Cu denote wt % of the respective elements.)   
     
     
         2 . The high-strength austenitic stainless steel according to  claim 1 , wherein the number of surface cracks is 0.3 or less per meter (m). 
     
     
         3 . The high-strength austenitic stainless steel according to  claim 1 , wherein a hardness is 190 Hv or more. 
     
     
         4 . The high-strength austenitic stainless steel according to  claim 1 , further comprising, in percent by weight (wt %), 0.05% or less of P, 0.01% or less of S, 0.1% or less of Al, 0.01% or less of Ti, and 0.005% or less of B.