| 摘要 |
PURPOSE: Lean duplex stainless steel and a manufacturing method thereof are provided to improve workability by simultaneously obtaining strength elongation and tensile ductility of 50% or more with a high strength of 800MPa or more. CONSTITUTION: Lean duplex stainless steel contains 0-0.08 wt% of C, 0-0.5 wt% of Si, 4-6 wt% of Mn, 19-23 wt% of Cr, 0-0.3 wt% of Ni, 0.18-0.40 wt% of N, remaining amount of Fe, and impurities. The distribution coefficient of the N(KN=N concentration densified in ferrite/N concentration densified in austenite) is in a range of 0.24-0.29. The distribution coefficient of the Mn(KMn=Mn concentration densified in the ferrite/Mn concentration densified in the austenite) is satisfied in a range of 0.65-0.80. [Reference numerals] (AA) Nominal stress(MPa); (BB) Comparative example 3; (CC) Example 1; (DD) Example 2; (EE) Example 3; (FF) Nominal strain(%) |
