Ultrasonic testing requirements for thick-walled seamless steel pipes

The principle of ultrasonic testing of thick-walled seamless steel pipes is that ultrasonic probes can realize the mutual conversion between electrical energy and acoustic energy. The physical properties of ultrasonic waves when propagating in elastic media are the basis of the ultrasonic testing principle of seamless steel pipes. When the ultrasonic beam emitted in a direction encounters a defect during propagation in the seamless steel pipe, a reflected wave is generated. After the defect reflected wave is picked up by the ultrasonic probe, the defect echo signal is obtained by the flaw detector, and the defect equivalent is given.

Detection method: The transverse wave reflection method is used to perform the inspection under the state of relative movement of the probe and the seamless steel pipe. Automatic or manual inspection should ensure that the sound beam scans the entire surface of the seamless steel pipe.

The longitudinal inner and outer wall defects of seamless steel pipes should be inspected separately. When inspecting longitudinal defects, the sound beam propagates in the circumferential direction in the wall of the seamless steel pipe; when inspecting transverse defects, the sound beam propagates in the axial direction of the seamless steel pipe in the wall of the seamless steel pipe. When detecting longitudinal and transverse defects, the sound beam should be scanned in two opposite directions in the seamless steel pipe.

The flaw detection equipment includes pulse reflection multi-channel or single-channel ultrasonic flaw detectors, the performance of which must comply with the provisions of JB/T 10061, as well as probes, detection devices, transmission devices, and sorting devices.