Surface Treatments and Temperature Effects

The role that the external surface exerts on the fatigue strength of materials will never be stressed enough. In high cycle fatigue and to a less extent also in low-cycle fatigue, the first and most effective barrier to the demolishing action of cyclic loads is provided by the surface. A really well-treated surface will make a workpiece last fatigue as expected while an inaccurate and odd surface will lead to an early as well unexpected fatigue failure.