Ultrasonic flaw detection of small-caliber seamless steel tube

Small-caliber seamless steel tube are one of the more important features of seamless steel tubes and have various technical advantages and various applications. Small seamless steel tubes with small outside diameter can be called small-diameter seamless steel tubes. Next, it mainly explains how the small-caliber seamless steel pipe is used for inspection and inspection.

Ultrasonic probes can realize the mutual conversion between electrical energy and sound energy and the physical characteristics of ultrasonic wave propagation in elastic media are the basis of ultrasonic flaw detection principle of steel pipe. The directional transmitted ultrasonic beam encounters defects when it propagates in the tube, causing both wave reflection and wave attenuation. After the signal processing of the flaw detector, such as using the reflection method to detect flaws, the flaw echo signal can be obtained. If the penetration flaw detection method is used, the defect signal can be obtained by the attenuation degree of the transmitted wave. Both can be given quantitative defect indication by the instrument.

How to detect the detection of small-caliber seamless steel tubes? Generally the following steps are taken:
The transverse wave (or plate wave) reflection method (or penetration method) is used for automatic inspection in the state where the probe and the steel pipe move relative to each other. Only the special small-diameter steel pipe can be manually checked. During the automatic or manual inspection, the sound beam must be scanned on the entire surface of the tube.

Note: Both ends of the steel pipe will not be effectively tested during automatic inspection, but this area should be controlled within 200mm. When the longitudinal defect is examined, the sound beam propagates in the circumferential direction within the tube wall; when the transverse defect is examined, the sound beam propagates in the direction of the tube axis within the tube wall. Inspection of longitudinal and transverse defects shall be performed in two opposite directions of the tube. The supplier only verifies the longitudinal defects when the buyer does not propose to verify the lateral defects. After agreement between the supply and demand sides, longitudinal and lateral defect inspections can only be performed in one direction of the pipe. The coupling medium with good coupling effect and no damage to the surface of the steel pipe should be selected for automatic or manual inspection.