To provide a high-modulus graphitized fiber capable of expressing high torsion strength in the form of FRP reinforced therewith, and to provide a method for producing the graphitized fiber.
The graphitized fiber has the following characteristic: the product of the ratio of crystallite size Lc(nm) to tensile modulus E(GPa) and the compressive strength C(MPa) in the 0° direction, i.e. E×C/Lc, falls within a range of 110×103 to 20×103 GPa×MPa/nm. The graphitized fiber is produced by heating a carbonized fiber in an inert atmosphere under a condition meeting the relationship: 200≤(T-2,000)×t≤200,000(°C×s)[ wherein, T(°C) is the maximum baking temperature higher than 2,000°C, and t is a residence time (sec) in the baking temperature region (wherein 150≤t≤1,200)] to graphitize the carbonized fiber while drawing it by a factor of 0.9-1.2.
ITO TAKAHIRO
WASHIYAMA MASAYOSHI
