| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive ferritic stainless steel sheet for a formed spring, which has spring characteristics comparable to those of austenitic stainless steel used for various formed springs, and uses few expensive component elements such as Ni, and to provide a manufacturing method therefor. SOLUTION: The ferritic stainless steel for the sheet comprises not more than 0.03% C, not more than 0.03% N, not more than 1.00% Si, not more than 1.00% Mn, 16-20% Cr, not more than 0.60% Ni, 8×(C+N)% to 0.80% Nb by mass% and the balance Fe with unavoidable impurities. The method for manufacturing the sheet comprises the steps of: cold-rolling the ferritic stainless steel so as to store distortion corresponding to that stored by cold rolling with a reduction of 15% or higher inside it; and subjecting to final heat treatment in a temperature range of 550 to 750°C. Thus manufactured stainless steel sheet has a 0.2% yield strengthσof 600 MPa or higher, and such elongationε(%) as to satisfy both relationships ofε≥-0.02×σ+22 andε≥5. COPYRIGHT: (C)2006,JPO&NCIPI
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