New Ultrasonic Method for Evaluating Weld Penetration in Step-Type Weld Joints

The welding process on step joint geometries in cylindrical parts produces compressive forces which can couple the interfaces at the weld joint. Traditionally, an ultrasonic window has been machined in the joint corner similar to a radiographic window as an indicator of weld penetration. The window serves as a reflector which ensures that the traditional ultrasonic angle beam shear method will detect the unpenetrated weld interface. Several window designs have been used successfully; however, there are problems associated with the use of ultrasonic windows. The welder’s desire for a small window to minimize the manmade void near the root of the weld, makes it difficult to accurately machine and properly clean the window. It is also undesirable to have a hole at the root of the weld. These factors increase the cost of welding for the sake of the ultrasonic inspection