| 摘要 |
PURPOSE: A continuous annealing method of super duplex stainless steel with excellent impact toughness and coil shape is provided to obtain excellent impact toughness by preventing the generation of sigma phases and to obtain excellent coil shape by preventing the lateral deformation of materials. CONSTITUTION: A continuous annealing method of super duplex stainless steel with excellent impact toughness and coil shape is as follows. When a super duplex stainless hot coil is annealed, tensile stress is applied within 0.3-0.5kgf/mm^2. The super duplex stainless hot coil is composed of 0.030 wt.% or less of C, 0.8 wt.% or less of Si, 1.2 wt.% or less of Mn, 0.035 wt.% or less of P, 0.020 wt.% or less of S, 24-26 wt.% of Cr, 6.0-8.0 wt.% of Ni, 3.5-5.0 wt.% of Mo, 0.24-0.32 wt.% of N, and the rest of Fe and other inevitable impurities. [Reference numerals] (AA) True strain; (BB) Range of the present invention; (CC) No width change; (DD) Tensile stress controllable range; (EE) Sigma phase decomposition(superior impact toughness); (FF) Annealing temperature(°C); |
