NDT Training has evolved over the years from the General Dynamics “reversible” self study books to interactive CDs and online courses. The modern course delivery has made it very easy for technicians to learn the theoretical concepts at their own pace. However, NDT is also a skill based profession. Hands-on training is essential to the success of a good NDT program. When choosing an NDT Training program, employers need pay special attention to flaw specimens utilized by the NDT school for training. The flaw specimens during training and examination should reflect the application of the employer. As an example, let’s discuss an ultrasonic testing application.
Ultrasonic Testing is a very versatile volumetric inspection method. It is successfully used to test various product forms such as welded assemblies, cast components, formed or forged components and welded assemblies. It can be utilized to test ferrous alloys, non ferrous alloys, super alloys, composites, powder metallurgy products, plastics, and additive manufacturing materials. UT can be utilized for detecting inherent, processing, and service related flaws.
- Picking one category, welded assemblies, the indications observed from structural steel joints are going to be very different from nozzle welds in pressure vessels.
- Within structural steel components, welds in Austenitic or Duplex Stainless Steels present very different challenges compared to Carbon Steels.
- For CS Structural Welds, the presence of backing bar can puzzle an accomplished ultrasonic technician familiar with nozzle welds in pressure vessels. The commentary section C-6 of AWS D 1.1: Structural Welding Code discusses the problems faced while scanning backing bar in great detail. However, technicians need to practise on flaw specimens with backing bar having different joint geometries, root gaps, faying gaps, and backing bar sizes to delineate actual flaws from indications received from geometric conditions.
Asking a technician to inspect such complex geometries without proper training is similar to asking a teenager who just received their driving permit to start driving a tractor trailer. Unfortunately, this happens more frequently than we would expect in case of UT technicians.