The ultrasonic inspection of thin-walled tube is as follows:
(1) test method. The ultrasonic inspection of thin-walled tube is mainly carried out by automatic inspection. The form is:
① fix the probe, make the steel pipe spiral forward through the mechanical transmission device, and make the probe move relative to the axis of the pipe. Usually, single crystal immersion line focus probe and single channel A-type pulse reflection ultrasonic flaw detector are used to detect the longitudinal defects (along the tube axis) in the inner and outer walls of the tube.


② the pipeline is rotated by mechanical transmission equipment. The probe is driven by the driving trolley and moves along the axis of the pipeline at a uniform speed. The probes, instruments and detection defects used are the same as ①.


③ when the probe rotates, the mechanical transmission equipment will directly enter the pipeline. In general, multiple probes with different functions and different forms are used. The multi-channel ultrasonic flaw detector is used to detect the longitudinal, transverse and layer defects of the inner and outer walls of the pipeline at the same time. At the same time, measure the wall thickness of the pipe and check the ovality.


The detection method has a high degree of automation, and can detect multi-directional defects at the same time, and can be combined with microprocessor or automatic multi recorder for automatic printing records, quality classification, etc.


(2) detection frequency. Because of the thin wall and small size of the pipe, it can be effectively matched. Defects are detected, usually at 5 MHz or higher.


(3) acoustic coupling.
No matter which method is used, the water treated is used as coupling agent in the ultrasonic testing of small diameter thin-walled tube. The basic requirement is to ensure that the water is fully wetted on the steel pipe surface without bubbles, and to reduce the corrosion of water on the steel pipe material.


(4) adjustment of incidence angle of sound wave.
① horizontal offset method: adjust the axis of the probe to be parallel to the central axis op of the tube, and translate the distance from the op section, which is called eccentricity x (determined by the incidence angle of the sound wave), so that the sound wave inclines to the surface of the electron tube. After refraction, it transmits inside the pipe material and reaches the inner wall of the pipe.


② deflection method: the axis of the probe coincides with the central axis op of the tube, and the pivot point of the probe deflects by a certain angle to make the sound wave incline to the tube surface and refract. And to the inside of the pipe material

The ultrasonic inspection of thin-walled tube is as follows:
(1) test method. The ultrasonic inspection of thin-walled tube is mainly carried out by automatic inspection. The form is:
① fix the probe, make the steel pipe spiral forward through the mechanical transmission device, and make the probe move relative to the axis of the pipe.  Usually, single crystal immersion line focus probe and single channel A-type pulse reflection ultrasonic flaw detector are used to detect the longitudinal defects (along the tube axis) in the inner and outer walls of the tube.


② the pipeline is rotated by mechanical transmission equipment. The probe is driven by the driving trolley and moves along the axis of the pipeline at a uniform speed. The probes, instruments and detection defects used are the same as ①.


③ when the probe rotates, the mechanical transmission equipment will directly enter the pipeline. In general, multiple probes with different functions and different forms are used. The multi-channel ultrasonic flaw detector is used to detect the longitudinal, transverse and layer defects of the inner and outer walls of the pipeline at the same time. At the same time, measure the wall thickness of the pipe and check the ovality.


The detection method has a high degree of automation, and can detect multi-directional defects at the same time, and can be combined with microprocessor or automatic multi recorder for automatic printing records, quality classification, etc.


(2) detection frequency. Because of the thin wall and small size of the pipe, it can be effectively matched. Defects are detected, usually at 5 MHz or higher.


(3) acoustic coupling.
No matter which method is used, the water treated is used as coupling agent in the ultrasonic testing of small diameter thin-walled tube. The basic requirement is to ensure that the water is fully wetted on the steel pipe surface without bubbles, and to reduce the corrosion of water on the steel pipe material.


(4) adjustment of incidence angle of sound wave.
① horizontal offset method: adjust the axis of the probe to be parallel to the central axis op of the tube, and translate the distance from the op section, which is called eccentricity x (determined by the incidence angle of the sound wave), so that the sound wave inclines to the surface of the electron tube. After refraction, it transmits inside the pipe material and reaches the inner wall of the pipe.


② deflection method: the axis of the probe coincides with the central axis op of the tube, and the pivot point of the probe deflects by a certain angle to make the sound wave incline to the tube surface and refract. And to the inside of the pipe material