The effect of rest periods on the fatigue life of medium carbon steel under different fatigue loading

الملخص EN

The fatigue crack growth (FGG) behaviour of medium carbon steel alloy under different rest periods is investigated under room temperature and stress ratio R = -1 using replication technique.

This work examines the constant and variable amplitude torsional fatigue under different time of rest periods.

The short and long fatigue crack growth equations are obtained experimentally.

The average grain size diameter is 0.277 mm which separates between short and long crack region.

The main remarks can be drawn from this work are : The fatigue life of specimens is increase by rest periods under constant amplitude tests.

The factor of increasing is about 1-12.

While this factor becomes 1.75–8.7 times the predicted life for variable amplitude tests.

Rest periods generate strain ageing which in terms increase the total fatigue life.