Temperature dependence of stress-lifetime fatigue curves

By analysing several finite-life fatigue curves obtained at various tempera tures, a relation describing the temperature dependence of fatigue strength is proposed, based on the Basquin equation. Accordingly, an approximate in verse law between fatigue strength and the square root of absolute temperat ure is demonstrated. Moreover, a boundary temperature above which creep beg ins to play a significant role is estimated. A simple extension of the rela tionship to the low-cycle fatigue region, allows one to determine predictiv e curves describing fatigue behaviour at various temperatures, even in case s where only a single fatigue curve at a given temperature plus the tempera ture dependence of tensile strength are known.