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Ultrasonic impact treatmentUltrasonic weld impact treatment - HFMI/UIT Improved fatigue resistance HFMI (High Frequency Mechanical Impact), also known as UIT (Ultrasonic Impact Treatment), is a high-frequency weld impact treatment designed to improve the fatigue resistance of welded structures. It is a cold mechanical treatment that involves striking the weld toe with a needle (or striker) to create an enlargement of its radius and to introduce residual compressive stresses. The new recommendation published by the IIW proposes a gain of 4 to 8 fatigue classes depending on the yield strength of the treated steels. The improvements actually noted in the study with our equipment show even more significant improvements. To know more about our ultrasonic impact treatment, download our flyer, section ultrasonic impact treatment I download! Principle of ultrasonic weld impact treatment Improvement of the lifetime of a part after ultrasonic weld impact treatment 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. Correction of distortions due to welding Close Browse the tabs below to explore in detail the objective, applications, studies and recommendations of ultrasonic impact treatment. ObjectiveApplicationsStudies and recommendationsObjective Objective - Ultrasonic impact treatment 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. Why should I use it? To increase the fatigue life To increase the fatigue limit To reduce the weight To reduce or compensate the distortions induced by the welding When should I use it? 1In the design calculations 2On new parts production 3For maintenance and repair 4To extend the fatigue life of service parts Applications Fatigue resistance technologies, such as NOMAD (ultrasonic weld impact treatment equipment), are regularly and successfully used in many sectors: aerospace, energy, automotive, defence, transportation and infrastructure. Agricultural machinery Handling and transport Industrial equipments Infrastructures Naval / Marine Power Generation 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. Studies and recommendations The effectiveness of the process has been demonstrated in numerous international research studies. Do you notice cracks on your mechanically welded parts and sub-assemblies? The characterisation of your materials and the measurement of residual stresses after welding will enable you to improve the design of your parts and your welding processes. Download the brochure of our laboratory dedicated to residual stress and material characterisation. I Download! -
Ultrasonic impact treatment equipmentNOMAD - Portable ultrasonic impact treatment equipment Our NOMAD equipment is designed and built to guaranty weld impact treatment requirements and needs on site but also in the production workshop. Its strong design, protected by a transport wheelcase and its STRESSONIC® ultrasonic technology ensure easy access to the areas to be treated combined with an optimal quality of treatment. Our lightweight and portable NOMAD HFMI/UIT equipment is used directly on-site for the treatment of your welded structures (examples: road or rail infrastructure, heavy machinery). This solution reduces: the resources required for treatment, the infrastructure downtime and the maintenance costs. Our equipment is designed to be strong enough to withstand outdoor use. Moreover, our international network, our reliability and our responsiveness mean that we can offer you quality services anywhere in the world. Download our dedicated flyer to discover NOMAD's advantages and accessories Download ! SONATS provides distance learning of our ultrasonic impact treamtment equipment NOMAD. From equipment presentation to first level maintenance. Get safely trained ! Contact-us for more information. Weld impact treatment applications Convex welding Heat affected area Flat and concave welding Examples of portable ultrasonic weld impact treatment equipment applications STRENGTHENING DEFENCE VEHICLES For defence vehicles such as forward crossing vehicles need require optimum quality of the welds and the structure is vital. This is why the NOMAD portable device equipped with specific end-pieces (standard and multi-impact) was used for preventive treatment of weld impact treatments and peening of flat surfaces. The aim is to improve resistance to stress corrosion cracking for aluminium alloy defence vehicles. ROAD INFRASTRUCTURES REPAIRS Faced with the increase of traffic and the increase of the transported loads, mechanically welded assemblies of road infrastructures are subjected to considerable tensile stresses. SONATS supplied the NOMAD portable device for curative treatment of platforms on welded steel metal bridges, aiming to repair and improve the lifetime of welds. NOMAD was also been used on new bridges in the USA, Canada, Europe and Asia for crack prevention treatment. REPAIR OF MARINE STRUCTURES Marine structures are subject to cyclic stress due to variable loading and the aggressive environment. Equipped with a NOMAD fitted with an angled end-piece for hard-to-reach areas, operators applied a curative peening treatment to an aluminium patrol boat that had suffered corrosive and mechanical damage. RAILWAY TRACK REPAIRS The frequency of trains and their associated weight are very variable and subject the railway tracks to high compression which cracks the welds of the rails at certain junction points. The railway company worked with SONATS to develop a new repair procedure with the NOMAD portable equipment, equipped with a treatment head specifically designed for the work and an inclined end-piece for treatment in the field to access difficult to reach areas. Learn more about our range of customized accessories and peening head -
Ultrasonic impact treatment servicesUltrasonic impact treatment services With more than 20 years of experience in ultrasonic surface impact treatments for the improvement of fatigue performance, SONATS proposes weld impact treatment services for your welded structures. Thanks to the simplicity of our portable equipment, SONATS can send a team of technicians to your site within one to three weeks whether it be in France or around the world. SONATS performs preventive treatment where fatigue cracks have initiated or curative treatment where there is propagation of cracks. SONATS is also open to partnerships with companies wishing to offer such services using our portable ultrasonic weld impact treatment system, the NOMAD. Download our white paper on ultrasonic needle peening Download Examples of ultrasonic impact treatment services (HFMI-UIT) on customer sites PREVENTIVE TREATMENT FOLLOWING THE DISCOVERY OF FATIGUE CRACK INITIATION Following a study commissioned by the port authority of DOVER, the consulting firm warned about crack initiation. After analysis, it was decided to apply a high-frequency mechanical impact treatment (HFMI-UIT) on all critical areas of each bridge to avoid the spread of cracks (about 4km of weld toe). Two devices were rented for 1 month, for use 7 days a week and 10 hours a day. This solution was used to extend the fatigue lifetime by at least two times that of the initial life cycle before HFMI. PEENING OF ROAD INFRASTRUCTURES Cracks on the weld toe of the upper deck of the George Washington Bridge (NY) were observed. A preventive and curative treatment was then applied by the American Bridge team over a period of one year using 4 devices. The cracking preventive treatment on the weld bead of the zones concerned made it possible to extend the fatigue lifetime of the bridge. TREATMENT OF CIRCUMFERENTIAL WELDING ON A HEAVY PLANT FRONT LOADER To increase the fatigue lifetime of a circumferential weld of a front loader lift arm, SONATS technicians, equipped with two NOMAD devices, went to the customer site to apply a preventive treatment on all welds. This treatment made it possible to increase the number of lifting cycles from 200,000 to 5 billion TREATMENT OF AN ALUMINUM SUPER STRUCTURE OF A WAR VESSEL Several categories of US Navy vessels were built with a 5XXX series aluminium chosen for its mechanical properties (AA5456 and AA5083). However, high temperatures and the saline environment sensitise the surface and cause cracking due to stress corrosion. SONATS technicians, equipped with our portable NOMAD system, intervened on several vessels to apply an impact treatment to weld toes in critical areas. The ultrasonic impact treatment process is approved by the US Navy. Scientific and technical publications Read technical and scientific publications discussing about ultrasonic weld impact treatment such as our white paper (Fatigue life improvement of welded structures by ultrasonic needle peening) gathering SONATS' experiences.
HFMI treatment – High Frequency Mechanical Impact treatment
Find out more about the HFMI/UIT process, our equipment and service:
The STRESSONIC® technology is an innovative, high-performance technology providing an alternative solution to the traditional impact treatment technique: ultrasonic impact treatment – UIT or high-frequency mechanical impact – HFMI. This is a cold impact mechanical treatment projecting needles/impactors onto the weld toe of welded assemblies by means of ultrasonic wave frequency.
Hammer or weld impact treatment is a surface treatment for metal parts and welded assemblies that improves fatigue resistance, increases stress corrosion resistance and is used to correct welding distortion.
SONATS has developed a portable ultrasonic impact treatment (HFMI / UIT) equipment called the NOMAD. This device has been designed for operations in the production workshop but also on site thanks to its protected transport wheelcase facilitating access to the areas to be treated.
SONATS provides on-site services all around the world to execute ultrasonic weld impact treatment on metal parts and welded assemblies.
