Ultrasonic Impact treatment equipment on structures and assemblies exposed to corrosive environments, the Ultrasonic impact treatment process helps to delay or even eliminate the appearance of cracks
|Amplitude of vibration (a）:|
What's is ultrasonic impact treatment
Shot Peening Equipment by Ultrasonic Impact Treatment technology allows the use of high quality media. Quality madia combined to the real-time control of parameters, ensures a repeatable and efficient treatment. Ultrasonic Shot Peening (USP) induces a low roughness and a better surface quality compared to the conventional shot peening. This has a direct influence on fatigue-life enhancement and prevent Stress Corrosion Cracking.
|Maximum Output||800 Watt|
|Power Supply||220V / 50-60 Hz|
|Ultrasonic Generator||Size||250(W) x 310(L) x 135(H) mm|
|Feature||Ultrasonic Amplitude Adjustable|
Inscreasing productivity and quality
Improving fatigue life
Treatment of complex geometry parts
Process control and repeatability
Low roughness (see image above)
Shorter treatment cycle time
Reducing consumption of beads, energy and compressed air
Integration in the production line (lean manufacturing)
INCREASE IN STRESS CORROSION CRACKING (SCC) RESISTANCE
The creation of superficial compression, by peening, due to the impact of the needles on the material also makes it possible to improve the resistance for stress corrosion cracking.
As this phenomenon occurs on structures and assemblies exposed to corrosive environments, the HFMI/UIT process helps to delay or even eliminate the appearance of cracks.
CORRECTION OF DISTORSIONS DUE TO WELDING
The stresses created by welding processes cause distortions in the welds between the panels.
These well-known distortions occur during the cooling phase of the weld, when the molten metal shrinks, resulting in plastic deformation of the welded metals.
In order to eliminate tensile stress, conventional stress relieving processes are currently applied locally (heating, TIG dressing, etc.). These processes restore a stress level close to 0 MPa at the surface and at a depth but do not correct the defect created by the weld.
The ultrasonic impact treatment (HFMI / UIT) process not only allows to create residual compressive stresses, which are much more beneficial than stress relief but also allows to straighten the deformations caused by welding. The 2 in 1 effect of ultrasonic impact treatment (HFMI / UIT) is particularly valuable when the aim is to improve the fatigue strength of steels, aluminium and other metal alloys while correcting geometrical defects.
FOR BOTH CURATIVE AND PREVENTIVE TREATMENT
When producing a part or making and assembling a structure, the first step in controlling fatigue resistance is to assess the most critical areas where cracks may appear. Then the best process to apply must be determined. The key to this choice is to assess whether a method of improving fatigue resistance is needed before the onset of major damage. A preventative rather than a corrective approach is much better in order to minimise costs and maximise profits.
Ultrasonic impact treatment is one of the best preventive treatments to improve the fatigue resistance of welded structures
The UP could be effectively applied for fatigue life improvement during manufacturing, rehabilitation and repair of welded elements and structures. The UP technology and equipment were successfully applied in different industrial projects for rehabilitation and weld repair of parts and welded elements. The areas/industries where the UP was applied successfully include: Railway and Highway Bridges, Construction Equipment, Shipbuilding, Mining, Automotive and Aerospace. An example of application of UP for repair and rehabilitation of welded elements subjected to fatigue loading in mining industry is shown in Figure 7. Around 300 meters of welds, critical from fatigue point of view, were UP treated to provide improved fatigue performance of large grinding mills.
Application of UP for rehabilitation of welded elements of a large grinding mill
Based on the fatigue data and the solution described in , the UP was also applied during the rehabilitation of welded elements of a highway bridge over the Ohio River in the USA.
The bridge was constructed about 30 years ago. The welded details of the bridge did not have macroscopic fatigue cracks. The motivation for application of the UP for fatigue life improvement of this bridge was the fatigue cracking in welded elements and failure of one of the spans of another bridge of approximately the same age and design. The stages of preparation for UP treatment of the bridge and the process of UP treatment of one of the welded vertical stiffeners are shown in Figures 8 and 9. More than two thousand and five hundred welded details of the bridge structure that were considered to be fatigue critical were UP treated.