| 摘要 |
PURPOSE: A lean duplex stainless steel is provided to improve machinability by controlling phase fraction of ferrite and austenite and by obtaining corrosion resistance and simultaneously obtaining elongation percentage of high ductility of over 50 %. CONSTITUTION: A lean duplex stainless steel is comprised of below 0.08 % of C, below 0.2-3.0 % of Si, 2-4 % of Mn, 19-23 % of Cr, 0.3 %-2.5 % of Ni, 0.2-0.3 % of N, 0.5-2.5 % of Cu, a residual Fe, and unavoidable impurities. The stainless steel is comprised of 0.1-1.0 % of weight %. The stainless steel is comprised of ferrite of 55~25% and austenite of 45-75 % in the volume fraction. The content of the plasticity organic martensite is below 5% in the stainless steel. The stainless steel includes elongation percentage of over 50 %. [Reference numerals] (AA) Nominal stress(MPa); (BB) Comparative example 5; (CC) Example 2; (DD) Example 7; (EE) Example 6; (FF) Comparative example 2; (GG) Example 11; (HH) Example 5; (II) Example 8; (JJ) Example 4; (KK) Comparative example 1; (LL) Nominal transformation(%) |
