The fatigue notch factor, [K.sub.f], is defined in the present study as the ratio of fatigue strength of unwelded ([S.sub.uw]) and welded ([S.sub.w]) specimens at a given fatigue life, A, and temperature.
The resulting fatigue notch factor curves for welded specimens as a function of fatigue life at different temperatures are presented in Fig.
The fatigue notch factor ranged from 1.4 to 1.8 regardless of the testing temperature.
As for the fatigue notch factor decreasing slightly with life at 50[degrees]C, no physical meaning can be extracted because the displayed trend is not based on mechanical analysis but by data fitting.
The fatigue notch factor for the welded specimen varied between 1.4 and 1.8.