FIELD: reconditioning of pipe thread elements by method of plastic deformation combined with ultrasonic treatment; applicable in reconditioning of thread elements of drill, drive and tubing string pipes at repair depots and in the field conditions. SUBSTANCE: method provides for combined surface plastic deformation and ultrasonic treatment of the thread surface; the operations are carried out by a variable angular velocity in the course of the end and/or beginning of unscrewing of the thread members. Ultrasonic treatment is carried out during a definite time interval, and the amplitude and frequency of ultrasonic vibrations are controlled. The device for realization of the method has an ultrasonic vibratory system, replaceable tubular waveguide containing a thread member with helical grooves mating the member being treated and made in the length of the threaded section of the thread member. EFFECT: enhanced efficiency. 7 cl, 4 dwg
