Contact type monocrystal straight probe for flaw detection on exterior wall of steel pipe

Abstract

A contact type monocrystal straight probe for flaw detection on the exterior wall of a steel pipe comprises a shell, a coaxial cable, a wedge, a damping block, a piezoelectric wafer, and an acoustic impedance matching layer. The coaxial cable is embedded into the shell. The wedge is arranged on the lower end of the shell, and is prepared by sticking two layers together, namely a first sound conducting layer and a second conducting layer. The first sound conducting layer is covered on the second sound conducting layer, the upper surface and the lower surface of the second sound conducting layer are both in a dome shape, the upper surface of the first sound conducting layer is flat, the lower surface of the first sound conducting layer matches with the dome shape of the upper surface of the second sound conducting layer, and the first sound conducting layer is orderly provided with the acoustic impedance matching layer, the piezoelectric wafer, and the damping block from the bottom to the top. The core wire and ground wire of the coaxial cable are respectively connected to the conductive plating layers on the upper side surface and lower surface of the piezoelectric wafer through wires. Sound wave can be effectively reflected by utilizing the difference of sound speed in different materials, and thus the original convergent wave beams can even be changed to a parallel state so as to improve the resolution rate and detection range of the probe.

Description

technical field [0001] The invention relates to a contact type single crystal straight probe used for flaw detection on the outer wall of a steel pipe. Background technique [0002] For building materials and metal pipes, internal damage is prone to occur after long-term use in special environments or conditions. At present, the internal damage detection of materials is realized by ultrasonic waves, which are more commonly composed of ultrasonic probes and display devices, and signals are transmitted between the two through coaxial cables. The structure of the ultrasonic probe is: it is mainly composed of a shell, a wedge and a piezoelectric chip. The wedge is installed at the lower end of the shell. The set is equipped with a damping block, the piezoelectric chip is connected to the coaxial cable through a cable, and the remaining space in the shell is filled with sound-absorbing material. The above-mentioned wedge is made of plexiglass material. In actual use, the lower e...

AI Technical Summary

Problems solved by technology

The structure of the ultrasonic probe is: it is mainly composed of a shell, a wedge and a piezoelectric chip. The wedge is installed at the lower end of the shell. The set is equipped with a damping block, the piezoelectric chip is connected to the coaxial cable through a cable, and the remaining space in the shell is filled with sound-absorbing material. The above-mentioned wedge is made of plexiglass material. In actual use, the lower end of the wedge is a flat plate However, for pipes with small surface area and high curvature of the outer edge, the above-mentioned ultrasonic probe with flat wedge structure is very inconvenient and because the contact between the two is not very close, the detection results are prone to errors

In the prior art, there is an ultrasonic probe with a circular arch at the bottom of the wedge, but after changing the bottom of the wedge to a circular arch, the ultrasonic beam will appear in a concentrated state, such as figure 1 As shown, this is not conducive to the detection of steel pipe damage

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