Utilising Ultrasonic Peening for the Best Possible Results
Fatigue is the weakening of a material caused by repeatedly applied loads, Ultrasonic Peening extends fatigue performance. Depending on the cyclic nature of the stress, material can either fail quickly or over prolonged periods. Fatigue failures continually cost companies billions due to lost productivity, personal injury, machinery downtime and of course, bad PR for OEM’s! For welded-steel structures subject to dynamic loading, and the engineers who design them, fatigue life is a top priority. Traditional methods such as hammer peening and burr grinding provide an extension of fatigue life, but here at Technoweld, we recommend a vastly more effective and efficient technique; relatively unknown and implemented in Australia, called Ultrasonic Peening (UP).
What is Ultrasonic Peening and why are welds vulnerable without it?
UP is a mechanical method that can be applied to a weld to reduce tensile residual stresses. It locally modifies the weld toe geometry to vastly improve fatigue performance and prolong fatigue life. Furthermore, it reshapes the appearance of the weld toe and intensifies the compressive stress in areas of stress concentrations.
Technoweld Director, Graham Fry, says “The technology is unique as it induces a compressive stress rather than a tensile (or tension) stress. For material to crack, it needs to be in tension; it needs to be pulling apart. UP adds compressive stress at the toe of the weld, right where you have the highest stress. If something is in compression it can’t crack because it’s actually pushing together. That’s the difference between this method and all the other fatigue improvement methods.”
Ultrasonic Peening History and Implementation
UP was developed in 1972 by two Russian scientists to enhance the fatigue and corrosion attributes of ship and submarine structures. It is now utilised across a multitude of industries including but not limited to:
- Defence
- Aerospace
- Mining
- Offshore drilling
- Shipbuilding
- Infrastructure
- Automotive
- Energy production
- Construction
The ability and the speed in which it can be applied is more efficient than Tig Toe remelting, and rotary burr methods, it is significantly more controlled and effective in improving fatigue performance and can save downtime of plant equipment assets (which can often be millions of dollars per day).
In order to implement UP technology locally, Graham has spent over ten years extensively researching fatigue life improvement and testing the different methods. His research has put him in contact with one of the original Russian developers, with whom he is still in touch today. He has undertaken training in the United States and brought US and European experts to Australia to learn their techniques.
Of the extensive technology trials he has undertaken, Graham has concluded: “we’ve had a number of different cases where items were in a high fatiguing environment, they were lasting about 12 weeks. Through this treatment, we have pushed it out to 24 weeks initially, then out to 36. We’ve got proven examples, not just theory, that this technology works.”
Choosing a provider: What sets Technoweld apart
While there are limited suppliers of UP technology in Australia, Technoweld has a distinct competitive advantage. With our intimate welding knowledge and understanding of the technology, it places us at the cutting edge. Learn more about how we implement Ultrasonic Peening here. As a training provider, our welders are trained to ensure they understand and can apply the welding methods to meet the stringent requirements of Australian Standard AS 1554 part 5 – Welding of steel structures subject to high levels of fatigue loading. Graham Fry is one of the few individuals that has achieved inspection qualifications by all the major welding institutes around the world.
“At Technoweld, we can offer the whole solution. Offering the treatment itself is only one part of it. You have to provide the best possible starting point, in order to end up with the best possible finishing point. You have to control the quality of the weld prior to treatment. UP can be applied to achieve double the performance improvement, but at Technoweld, our starting point is already four times the performance improvement prior to treatment, by ensuring that the weld is done to the highest quality. With Ultrasonic Peening, we double that four times improvement to eight times improvement and that is our real value add,” he says.
“The technology is there to be used to our advantage. Based on all the research, in both service application and real life studies, it’s an area that’s only going to grow. The technology is there to support the Defence industry with the upcoming shipbuilding programs, aerospace programs, and all while supporting infrastructure such as the Techport upgrade. It is there to support industry as a whole.”