Lean duplex stainless steel having excellent bending processability

Abstract

Provided is a lean duplex stainless steel having excellent bending processability. The lean duplex stainless steel includes, in percent (%) by weight of the entire composition, 0.01 to 0.06% of carbon (C), 0.2 to 1.0% of silicon (Si), 3.5 to 6.5% of manganese (Mn), 18.5 to 22.5% of chromium (Cr), 0.05 to 0.25% of nitrogen (N), and the remainder of iron (Fe) and other inevitable impurities, wherein a sum of amounts of Cr and Mn is from 26.0 to 28.5% and a Cr/Mn ratio is from 3.4 to 4.1.

1 . A lean duplex stainless steel having excellent bending processability and comprising, in percent (%) by weight of the entire composition, 0.01 to 0.06% of carbon (C), 0.2 to 1.0% of silicon (Si), 3.5 to 6.5% of manganese (Mn), 18.5 to 22.5% of chromium (Cr), 0.05 to 0.25% of nitrogen (N), and the remainder of iron (Fe) and other inevitable impurities,
 wherein a sum of amounts of Cr and Mn is from 26.0 to 28.5% and a Cr/Mn ratio is from 3.4 to 4.1.   
     
     
         2 . The lean duplex stainless steel according to  claim 1 , wherein lean duplex stainless steel comprises 0.5% or less of nickel (Ni), 0.5% or less or copper (Cu), and 0.5% or less of molybdenum (Mo). 
     
     
         3 . The lean duplex stainless steel according to  claim 1 , wherein a volume fraction of a ferrite matrix structure in a microstructure is from 50 to 75%. 
     
     
         4 . The lean duplex stainless steel according to  claim 1 , wherein an elongation of the stainless steel is from 30 to 40%.