On a new temperature factor to predict the fatigue limit at different temperatures

This study is concerned with a non-conventional fatigue strength behavior of some materials with temperature. Notwithstanding the common reduction on fatigue limit of most materials with temperature, some materials show a non-conventional behavior, e.g. a temperature change from 20 °C to about 300 °C or 400 °C cause an increase in fatigue limit and/or tensile strength. The change in fatigue limit and tensile strength may have opposite trends. The existing ‘temperature effect’ parameters used in fatigue limit equations do not properly incorporate this non-conventional behavior. This study will propose a temperature factor that is able to properly incorporate the non-conventional behavior of some materials. It will also be shown that the new proposed temperature factor may be applied also to conventional materials with improved accuracy being than a more universal temperature factor.