| 摘要 |
PURPOSE: A method for preventing intergranular corrosion of welded portion in ferritic stainless steels is provided. CONSTITUTION: The method includes the steps of hot rolling a stainless steel comprising 0.02 wt.% or less of C, 0.5 wt.% or less of Mn, 0.04 wt.% or less of P, 0.01 wt.% or less of S, Cr 11 to 20 wt.%, 0.02 wt.% or less of N, a balance of Fe and incidental impurities at 1200 to 1250 deg.C, wherein 10x(C+N)<=Ti<= 25x(C+N); finish rolling the hot rolled stainless steel sheet at 750 to 900°C; hot annealing the hot rolled stainless steel sheet at 1000 to 1100°C, followed by quenching; cold rolling the quenched stainless steel sheet at a reduction ratio of greater than 70 %; cold annealing the cold rolled stainless steel sheet under the same condition as above hot annealing, followed by quenching, wherein the method for preventing intergranular corrosion of welded portion in ferritic stainless steels is characterized in that the ferritic stainless steel is heat treated for 1 to 5 hrs at 600 to 700 deg.C before welded.
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