Appeal No. 2003-0668
Application No. 09/530,451
7. A method of manufacturing a highly fatigue-resistant
steel wire comprising the steps of:
shaving a steel wire rod of pearlite structure containing
0.8-1.0 mass % of C and 0.8-1.5 mass % Si;
patenting the shaved wire rod;
drawing the patented wire rod into wire;
subjecting the resultant wire to strain relief annealing at
350-450° C without subjecting the same to quenching and tempering
process; and
shot peening the resultant wire.
The examiner relies upon the following references as
evidence of obviousness:
Yamao et al. (Yamao) 5,904,830 May 18, 1999
Takahashi (JP '833) 57-140833 Aug. 31, 1982
(Japanese patent)
Appellants' claimed invention is directed to a highly
fatigue-resistant steel wire comprising a pearlite structure, and
the method of manufacturing it. A surface region of the wire has
an average value of micro-Vickers hardness that is 50 higher than
the average value of an inner region. According to appellants'
specification,
it is a primary object of the present invention to
provide a steel wire and spring having a high thermal
resistance and a high fatigue strength that can be
produced without applying a quenching and tempering
process, namely, produced through a drawing process and
-2-
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