Detection of PT penetration test in Jiangsu by RT
Mr. Wang: 13102238283 (WeChat with the number) QQ:3144667033
Phone: 022-23892103 email: 182@rd-test.com
Nondestructive testing is the use of sound, light, magnetic and electric properties, without prejudice or does not affect the performance of the premise inspection object, whether or not the defects detected by uniformity inspection object, given the defect size, location, nature and quantity of information, and then determine the technical state of the detected object (such as qualified or not, the remaining life of all technical means). Commonly used nondestructive testing methods: ultrasonic testing (UT), magnetic particle testing (MT), liquid penetrant testing (PT) and X (RT).
Ultrasonic testing has been introduced in detail, the following is a brief introduction and comparison of the remaining three.
First of all, to understand the principle of magnetic particle testing. The ferromagnetic material and the workpiece is magnetized, due to the existence of discontinuities, the workpiece surface and near surface magnetic field lines have local distortion, and the leakage magnetic field applied on the workpiece surface adsorption of magnetic powder, formed in the right light visible magnetic marks, which do not show continuous position, shape and size the.
The applicability and limitations of magnetic particle testing:
1, magnetic particle inspection is suitable for the detection of ferromagnetic material surface and near surface size is very small, very narrow gap is difficult to see the visual discontinuity.
2, magnetic particle testing can be in a variety of cases of parts and components, but also a variety of components for testing.
3, can be found in crack, inclusion, crack, flake, folding, cold laps and loose defects.
4, can not detect the magnetic particle inspection of austenitic stainless steel and austenitic stainless steel welding seam, also can not detect the titanium copper aluminum magnesium non-magnetic material. It is very difficult to find the surface shallow scratches, buried deep holes and the angle between the surface of the workpiece and the surface of the workpiece is less than 20 degrees.
The basic principle of liquid penetrant inspection, parts of the surface is applied with a fluorescent dye or dye coloring, in a period of time under the effect of capillary permeability, fluid can penetrate into the cracks; the removal of redundant penetrant surface parts, and then applying the imaging agent, in the same parts of the surface, in the capillary under the action of imaging agent will attract the permeate defects to retain the permeate flow back to the developer, in a certain light (UV or white light), permeate traces at the defect of being realistic, (green fluorescent yellow or bright red), so as to explore the morphology and distribution of the measured defect state.
Advantages of penetration testing:
1, can detect a variety of materials;
2, with high sensitivity;
3, display intuitive, easy to operate, low detection cost.
And the shortcomings of penetration detection:
1, is not suitable for inspection of porous loose material made of the workpiece and the surface roughness of the workpiece;
2, the penetration detection can only detect the surface distribution of defects, it is difficult to determine the actual depth of the defect, so it is difficult to make quantitative evaluation of defects. The detection results were also affected by the operator.
Finally, ray detection, because there will be loss across the X ray irradiation object, different thickness and different materials on their absorption rate, and the film on the other side of the object being irradiated, because radiation intensity have different corresponding graphical assessment personnel can according to the image to determine the object whether there are defects and defect properties.
Dye penetrant inspection
Applicability and limitations of radiographic testing:
1. It is more sensitive to detect the defect of volume type, and it is easy to identify the defects.
2, X-ray film is easy to retain, traceability.
3, visually display the shape and type of defects.
4, defects can not locate the depth of the defect, while the detection of the thickness is limited, the film needs to be sent to wash, and some harm to the human body, higher cost.
All in all, ultrasonic, X ray flaw detection is applicable to the detection of internal defects; ultrasonic which is suitable for more than 5mm, and the shape of the components, X ray can not locate the buried depth of the defect, radiation. Magnetic particle and penetrant flaw detection is applicable to the surface defects of the flaw detection parts. The magnetic particle inspection is only limited to the detection of magnetic materials