Ultrasonic inspection of austenitic welded joints of equipment of nuclear power plant

The ultrasonic control technique has been checked according to main provisions of the instruction during experimental-production control of welded joints of austenitic pipeline of 560x34 mm of 12Kh18NKh12T steel welded by electrode of austenite-ferrite class. The weld seam root of the above pipeline has been welded by means of argon-arc welding. Alpha-phase content in a melt metal has been at 3-4% level. Real and artificial defects in a form of slag inclusions, pores, asbestos pieces have been in the seam metal. It is shown that longitudinal ultrasonic vibrations in a clad austenitic metal have less damping than transverse vibrations at the same wave length and may be recommended for control by the direct beam of austenitic welded joints of 12Kh18N12T steel. The recommended by normalyzing materials control sensitivity level ensures revealing dangerous defects of planar type in a welded joint root not always found by radiation control methods. A rejected sensitivity level which does not lead to re-evaluation of items as a result of ultrasonic longitudinal wave reflection from dendrite welded joint structure is chosen