| 摘要 |
PROBLEM TO BE SOLVED: To optimally reduce the fatigue failure starting point as well as improve the material strength to obtain a steel wire having high fatigue characteristics by regulating the lattice strains of steel wire having a pearlite structure the specified in ratio of the contents of C and Si, to be in a specified range. SOLUTION: This steel wire is the one having a pearlite structure and having chemical components contg., by weight, 0.7 to 1.0% C and 0.5 to 1.5% Si, in which, in the case where the lattice constant is defined as (a), the lattice strainsΔaLS is allowed to satisfy 0.01×a<=ΔaLS<=0.002×a. At this time, the chemical components of the steel wire are preferably incorporated with Mn and Cr respectively by about<=1%, and the range of the lattice constant (a) is suitably regulated to be in the range of 2.8670 to 2.8705Å. It is optimal that this steel wire is formed into a spring for automotive parts requiring fatigue strength or is utilized for reinforcing such as PC steel stranded wire by executing spring working and stranding working. Moreover, in the case of spring working, it is preferably that the surface residual stress is regulated to about <=100 MPa or is the compressive stress.
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