Ultrasonic peening can be used to reduce tensile stresses, introduce compressive stresses and remove surface defects.
Due to increased surface hardness, improved surface quality and lower Ra values, the Ultrasonic Peening treated surfaces show reduced rate of near-surface micro pitting fatigue. The reduction of micro pitting is the main cause for the improved fatigue surface resistance. Measurements show that the LETS Global Ultrasonic Peening treatment decreases tensile residual stresses down to 400MPa at the surface. The change in residual stresses goes as deep as 2mm. This is of great benefit to a wide range of structures, including brackets, web frames, crane frames just to name a few.
For cylindrical parts the treatment is also available. Our Ultrasonic Peening systems can easily be adapted to lathes, milling machines or any alternative robotic system.
The video below shows a surface treatment carried out manually in a FPSO cargo tank on a fatigue hot-spot. This type of treatment will increase the fatigue crack resistance substantially.