Posters

Abstract

There is a scale effect in wind farms that requires the use of increasingly larger wind turbines. This implies the manufacture of increasingly larger marine structures, resulting in a real challenge for the manufacturing industry to design, build and maintain steel colossi. Never before has the industry faced pieces of such size and weight. The welding of these thermomechanical rolled steels more than 100 mm thick is a real challenge for today's industry, both in terms of the time required and the quality of the welds. Welding process with enormous heat inputs and narrow welding bevels are increasingly being used, which can result in weld defects. Today, weld certification to guarantee the absence of weld defects requires inspection processes based on NDT (Non-Destructive Testing), which require time, highly specialized personnel, and the technologies. The international codes for quality welds require volumetric NDT such as radiographic examination or Ultrasonic Testing based in pulse-echo; Radiographic examination is not an option because it is an exclusive process for Radiation Safety requirements and does not allow for parallel work in workshops in 24/7 shift. The MUT (Manual Ultrasonic Testing) is an inefficient process with poor detectability and many errors can occur. The latest standards in quality welds requires recordable ultrasound technologies based on ToFD (Time of Flight Diffraction) and PAUT (Phased Array), which have been well-known in the industry for more than 20 years. The objective of this paper is to introduce and presents the background and principles of IWEX ultrasonic imaging that was applied during the manufacturing of Monopiles in a large Offshore Wind Project in comparison with other NDT Ultrasound Technologies (MUT, UTPA, ToFD and Tandem), with interesting result in terms of POD (Probability of detection), Inspection Speed, Evaluation process, false calls or misinterpretations.