Austenitic stainless steels excellent in flexibility

Abstract

Austenitic stainless steels excellent in flexibility are provided. The austenitic stainless steel excellent in flexibility includes, by weight percent, 0.1 to 0.65% of Si, 1.0 to 3.0% of Mn, 6.5 to 10.0% of Ni, 16.5 to 18.5% of Cr, 6.0% or less of Cu (excluding 0), 0.13% or less of (C+N) (excluding 0), and the remainder including Fe and unavoidable impurities, wherein the work hardening formula H1 defined by the following formula is 300 or less. H1=−459+79.8Si−10.2Mn−8.16Ni+48.0Cr−13.2Cu+623(C+N).

1 . An austenitic stainless steel excellent in flexibility being characterized by comprising:
 by weight percent, 0.1 to 0.65% of Si, 1.0 to 3.0% of Mn, 6.5 to 10.0% of Ni, 16.5 to 18.5% of Cr, 6.0% or less of Cu (excluding 0), 0.13% or less of (C+N) (excluding 0), and the remainder comprising Fe and unavoidable impurities,   wherein the work hardening formula H1 defined by the following formula is 300 or less.
   H1=−459+79.8Si−10.2Mn−8.16Ni+48.0Cr−13.2Cu+623(C+N)
 
   
     
     
         2 . The austenitic stainless steel excellent in flexibility according to  claim 1 , being characterized by having the size of structure (D) of 20 to 40 μm. 
     
     
         3 . An austenitic stainless steel excellent in flexibility being characterized by comprising:
 by weight percent, 0.1 to 0.65% of Si, 1.0 to 3.0% of Mn, 6.5 to 10.0% of Ni, 16.5 to 18.5% of Cr, 6.0% or less of Cu (excluding 0), 0.13% or less of (C+N) (excluding 0), and the remainder comprising Fe and unavoidable impurities,   wherein the work hardening formula H2 defined by the following formula is 300 or less.
   H2=4.27+0.875(−459+79.8Si−10.2Mn−8.16Ni+48.0Cr−13.2Cu+623(C+N))−287D (D: the size of structure)
 
   
     
     
         4 . The austenitic stainless steel excellent in flexibility according to  claim 3 , being characterized by having the size of structure (D) of 20 to 300 μm. 
     
     
         5 . An austenitic stainless steel excellent in flexibility being characterized by comprising:
 by weight percent, 0.1 to 0.65% of Si, 1.0 to 3.0% of Mn, 6.5 to 10.0% of Ni, 16.5 to 18.5% of Cr, 6.0% or less of Cu (excluding 0), 0.13% or less of (C+N) (excluding 0), and the remainder comprising Fe and unavoidable impurities,   wherein M d30  defined by the following formula is 0 or less.
   M d30 =551−462(C+N)−9.2Si−8.1Mn−29(Ni+Cu)−13.7Cr
 
   
     
     
         6 . The austenitic stainless steel excellent in flexibility according to  claim 5 , wherein M d30  is −100 to 0. 
     
     
         7 . The austenitic stainless steel excellent in flexibility according to  claim 1 , wherein the difference value between TS (tensile strength) and YS (yield strength) is 300 MPa or less. 
     
     
         8 . The austenitic stainless steel excellent in flexibility according to  claim 2 , wherein the difference value between TS (tensile strength) and YS (yield strength) is 300 MPa or less. 
     
     
         9 . The austenitic stainless steel excellent in flexibility according to  claim 3 , wherein the difference value between TS (tensile strength) and YS (yield strength) is 300 MPa or less. 
     
     
         10 . The austenitic stainless steel excellent in flexibility according to  claim 4 , wherein the difference value between TS (tensile strength) and YS (yield strength) is 300 MPa or less. 
     
     
         11 . The austenitic stainless steel excellent in flexibility according to  claim 5 , wherein the difference value between TS (tensile strength) and YS (yield strength) is 300 MPa or less. 
     
     
         12 . The austenitic stainless steel excellent in flexibility according to  claim 6 , wherein the difference value between TS (tensile strength) and YS (yield strength) is 300 MPa or less.