Are Sonograms Safe?

Ultrasonic flaw detection is a method of inspecting part defects by using the characteristic of ultrasonic energy penetrating into the depths of metal materials and passing from one section to another. Inside the metal, when encountering the defect and the bottom surface of the part, reflected waves occur respectively, and a pulse waveform is formed on the phosphor screen. The position and size of the defect are determined based on these pulse waveforms.

Ultrasonic flaw detection

Ultrasonic flaw detection is a method of inspecting part defects by using the characteristic of ultrasonic energy penetrating into the depths of metal materials and passing from one section to another. Inside the metal, the reflected wave occurs when it encounters the defect and the bottom surface of the part, forming a pulse waveform on the phosphor screen. According to these

There are many types of ultrasonic waves when propagating in the medium. The most commonly used in inspection are longitudinal, transverse, surface and plate waves. Defects such as inclusions, cracks, tube shrinkage, white spots, and delamination in metal ingots, billets, medium and heavy plates, large forgings, and relatively simple shapes can be detected with longitudinal waves; transverse waves can be used to detect defects in pipes Defects such as circumferential and axial cracks, scratches, pores in the weld, slag inclusions, cracks, and incomplete penetration; surface waves can be used to detect defects on castings with simple shapes

The super-probe is a portable industrial non-destructive flaw detection instrument, which can quickly, easily, without damage, accurately detect, locate, evaluate and diagnose multiple defects (cracks, inclusions, folds, pores, trachoma, etc.) inside the workpiece.

It can be used in the laboratory and engineering field. This instrument can be widely used in manufacturing, iron and steel metallurgy, metal processing industry, chemical industry and other fields that require defect detection and quality control. It is also widely used in in-service safety inspection in aerospace, railway transportation, boiler and pressure vessels, etc. And life assessment. It is a must for the non-destructive testing industry.

(1) When the ultrasonic wave propagates in the medium, it has the characteristics of reflection on different quality interfaces. If a defect is encountered and the size of the defect is equal to or greater than the ultrasonic wavelength, the ultrasonic wave is reflected back on the defect, and the flaw detector can display the reflected wave. Out; if the size of the defect is even smaller than the wavelength, the sound wave will bypass the defect and cannot be reflected;

(2) The directivity of wave sound is good. The higher the frequency, the better the directivity. It radiates into the medium with a very narrow beam, making it easy to determine the location of the defect.

(3) The propagation energy of ultrasonic waves is large. For example, the energy transmitted by ultrasonic waves with a frequency of 1 MHz (1 MHz) is equivalent to one million times the sound waves with the same amplitude and a frequency of 1000 Hz (hertz).

Strong penetrating ability, the detection depth can reach several meters;

High sensitivity, can find reflectors equivalent to the air gap reflection ability of a few tenths of a millimeter in diameter; the size of detectable defects can usually be considered as 1/2 of the wavelength.

It is more accurate in determining the orientation, size, shape and other aspects of the internal reflector;

Only need to approach the object to be inspected from one side;

Defect inspection results can be provided immediately;

Safe operation and light equipment.

Be carefully operated by experienced personnel;

Human ears can feel frequencies above 20

Type B and C developed on the basis of type A flaw detector

(1) The sound beam of ultrasonic waves can be concentrated in a specific direction and propagate in a straight line in the medium with good directivity;

(2) During the propagation of ultrasonic waves in the medium, attenuation and scattering will occur;

(3) Ultrasound will generate reflection, refraction and wave mode conversion at the interface of heterogeneous media. By using these characteristics, the reflected waves reflected from the defect interface can be obtained, so as to achieve the purpose of detecting defects;

(4) The energy of ultrasonic waves is much greater than that of sound waves;

(5) The transmission loss of ultrasonic waves in solids is small and the detection depth is large. Due to the reflection and refraction of ultrasonic waves at heterogeneous interfaces, especially the interface between gas and solid cannot be passed. If there are defects such as pores, cracks, delaminations (gas in the defects) or slag inclusions (different media in the defects), the ultrasonic wave will be transmitted to the interface between the metal and the defects in whole or in part. Be reflected.

The reflected ultrasonic waves are received by the probe and processed by the internal circuit of the instrument, and the waveforms of different heights and a certain distance are displayed on the fluorescent screen of the instrument. The inspector judges the depth, size, and type of the defect in the workpiece according to the changing characteristics of the waveform.

The advantages of ultrasonic flaw detection are large detection thickness, high sensitivity, fast speed, low cost, harmless to the human body, and the ability to locate and quantify defects. However, the flaw display of ultrasonic flaw detection is not intuitive, the flaw detection technology is difficult, and it is easily affected by subjective and objective factors, as well as the inconvenient storage of the flaw detection results, which makes ultrasonic flaw detection also has its limitations.

What are the ultrasonic testing methods?

There are usually penetrating method, pulse reflection method, tandem method, penetrating method and reflection method.

What are the applications of ultrasound testing?

Water immersion (water spray) method for testing steel pipes and forgings; single (dual) probes for testing welds; multi-probes for testing large pipes; ultrasonic testing of sheet metal; ultrasonic testing of composite materials; testing of non-metallic materials.