Shotpeening

While shot peening the substrate is bombarded at an angle of 90 degrees with shot (metal, glass beads etc) in order to condense the surface. Any porosity will vanish and the surface will get harder, while a compressive stress is built up. This compressive stress will make the material less sensitive to fatigue, stress corrosion cracking and corrosion fatigue.

The shot may be hardened and has a rounded off shape.

A special form of shotpeening is the Micropeen®treatment.