What materials can you use for magnetic particle inspection?
Common metallic materials like nickel, iron, steel, and cobalt are all ferromagnetic and perfect candidates for magnetic particle testing.
Where is magnetic particle testing used?
Magnetic particle inspection is used for detecting defects (discontinuities in surfaces and shallow subsurfacaes) in ferromagnetic materials. By magnetization of the inspected area there is created a magnetic field. Magnetic flux does not change its direction in the defect-free area of the tested item.
What is the difference between dye penetrant and magnetic particle testing?
With dye penetrant, the liquid penetrant itself is the indicating material. The subject material in magnetic testing must be magnetized, whereas liquid penetrant techniques may be used on a wider variety of materials.
Which among the following is the last step in magnetic particle test method?
3. Which among the following is the last step in magnetic particle test method? Explanation: Different steps involved in magnetic particle test are cleaning the surface, magnetizing the metallic component, application of ferromagnetic powder, observation and inspection and demagnetization. 4.
What is RT in welding?
Radiographic Testing (RT) – This method of weld testing makes use of X-rays, produced by an X-ray tube, or gamma rays, produced by a radioactive isotope. The basic principle of radiographic inspection of welds is the same as that for medical radiography.
Which type of test the capillary action principle is used?
Dye penetrant test
Which type of forces are responsible for the capillary action in the dye penetrant inspection?
This capillary action is the result of the adhesion of the material being stronger than the cohesive force between the liquid molecules.
What is reverse capillary action?
With some pairs of materials, such as mercury and glass, the intermolecular forces within the liquid exceed those between the solid and the liquid, so a convex meniscus forms and capillary action works in reverse. In hydrology, capillary action describes the attraction of water molecules to soil particles.
Why is dye penetrant red?
Penetrants are classified into sensitivity levels. Visible penetrants are typically red in color, and represent the lowest sensitivity. Fluorescent penetrants contain two or more dyes that fluoresce when excited by ultraviolet (UV-A) radiation (also known as black light).
Which NDT technique works on the principle of capillary action?
The basic principle of liquid penetrant testing (PT) is capillary action, which allows the penetrant to enter in the opening of the defect, remain there when the liquid is removed from the material surface, and then re-emerge on the surface on application of a developer, which has a capillary action similar to blotting …
What is the basic principle of penetrant testing?
The principle of liquid penetrant testing is that the liquid penetrant is drawn into the surface-breaking crack by capillary action and excess surface penetrant is then removed; a developer (typically a dry powder) is then applied to the surface, to draw out the penetrant in the crack and produce a surface indication.
What is the working principle behind the eddy current inspection technique?
Eddy current testing uses the principle of electromagnetic induction to detect flaws in conductive materials. An excitation coil carrying current is placed in proximity to the component to be inspected.
Can you eddy current through paint?
The use of induction allows Eddy Currents to be created even if the material has paint coatings in place.