Thermal-state steel tube thickness online detection device

Abstract

The invention relates to the technical field of nondestructive detection, and particularly relates to a thermal-state steel tube thickness online detection device. The thermal-state steel tube thickness online detection device comprises a thermal-state steel tube erected on a roller bed, a centripetal back plate erected via a mechanical arm is arranged on the periphery of the thermal-state steel tube, and the device is characterized in that a plurality of detection heads corresponding to the circle center of the steel tube are arranged on the centripetal back plate, and the detection heads are connected with a pulse laser and a continuous laser via light guide arms respectively; the pulse laser and the continuous laser are placed in a refrigerating cabinet away from the steel tube, the pulse laser is connected with an upper computer, and the continuous laser is simultaneously connected with a TWM interferometer in the refrigerating cabinet. By using the light guide arms, the device occupies a small space, and is simple in structure and flexible in adjustment; the lasers can be placed a few meters away from the steel tube, so the working environment is wide, special protective measures are not needed, and the optical characteristics and stability of instruments are guaranteed.

Description

[0001] (1) Technical field [0002] The invention relates to the technical field of non-destructive testing, in particular to an online testing device for the thickness of a hot steel pipe. [0003] (2) Background technology [0004] Accurate on-line detection of hot steel pipe thickness is a difficult and demanding detection project. The high heat of the steel pipe makes it impossible to use traditional contact detection methods and equipment. It can only be measured by remote excitation and signal reception. [0005] The principle of pulsed laser ultrasound is to irradiate the pulsed laser on the metal surface, and generate ultrasonic signals through the ablation effect, and the signals are received by electromagnetic probes, air-coupled sensors, continuous lasers and other equipment. The patent with the notification number CN00809253.2 discloses a high-temperature pipeline detection method and device that uses a pulsed laser to excite a signal, receives the signal from a con...

AI Technical Summary

Problems solved by technology

The patent with the notification number CN00809253.2 discloses a high-temperature pipeline detection method and device that uses a pulsed laser to excite a signal, receives the signal from a continuous laser and sends it to a Fabry-Perot interferometer (FP interferometer) for demodulation. There are three disadvantages: First, the pulsed laser and continuous laser are placed in a high-temperature, high-humidity environment, and strict sealing and cooling measures must be taken for the laser, otherwise the performance and life of the laser will be seriously affected; second, the laser itself is relatively large. Coupled with the sealing and cooling device, it makes the volume expand, and usually the production site is tight, and there are many difficulties in the placement of large-volume testing equipment; the third is that the working principle of the FP interferometer itself makes it irrespective of the noise and low-frequency interference. Part or the high-frequency part of the effective signal concentration is equally sensitive, which eventually leads to a decrease in the signal-to-noise ratio of the interferometer demodulated signal, causing errors in thickness calculations

[0006] The patent with the notification number CN102506781A proposes a method of using an air coupler instead of a continuous laser and an interferometer for the same problem. Although the structure is simplified, this method itself has a fatal flaw in principle: the air-coupled sensor receives The frequency is low, and the center frequency is usually several hundred hertz (Hz), while the center frequency of the laser ultrasonic signal is several megahertz, which makes it difficult for the air-coupled sensor to effectively receive the laser ultrasonic signal, which brings a great deal of trouble to the subsequent signal processing. Difficulty, which seriously affects the calculation accuracy of pipe thickness

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