| 摘要 |
PROBLEM TO BE SOLVED: To provide a ferritic stainless steel screw which has strength equivalent to that of the conventional austenite-based stainless steel screw (SUSXM7), extends the lifetime of a die assembly for forming the screw and has corrosion resistance excellent than a temper colored austenitic stainless steel screw after being colored for color matching with a member, the screw using low-cost ferritic stainless steel. SOLUTION: The ferritic stainless steel screw is produced through making the tensile strength of a wire drawing material made of ferritic stainless steel 570 to 700 MPa and further by making the tensile strength after screw form rolling 580 to 730 MPa, the ferritic stainless steel having a chrome volume of 16 to 20% by weight, a carbon volume of 0.005 to 0.02% by weight, and a nitrogen volume of 0.005 to 0.02% by weight. Then, an oxidizing color development process for forming a film of 0.5μm or less in thickness is applied to the screw. COPYRIGHT: (C)2009,JPO&INPIT
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