Magnetic-Powder Testing MT

Magnetic particle inspection – non-destructive testing of welded joints

The quality of welded joints is of great importance for the durability of the structure. The joint is most likely to be weakened at the point of jointing, and the risk of mistakes being made during welding is very high. For this reason, this part of the structure is subjected to special inspection using, among other things, MT magnetic particle testing. This is the MT method, and the test is conducted using electromagnetic waves. A suitable powder allows the test results to be presented visually.

MT magnetic testing of welded joints is classified as a non-destructive quality control method. There is no risk of damaging the weld and the components being joined. The electromagnetic waves do not alter the properties of the material and the powder is easy to remove after the test is completed. The MT magnetic-powder method is used on finished welded joints of industrial objects, technical structures and even means of transport.

When performed correctly, the magnetic-powder MT test is able to detect inconsistencies with a high degree of accuracy. However, it takes an experienced team of people and the right equipment to carry out MT testing correctly. At Technic-Control Non-Destructive Testing Laboratory, we have such people at our disposal, thanks to which we have a high position among national market leaders. If you need accurate and conscientious non-destructive testing, contact our Technic-Control Nondestructive Testing Laboratory customer service.

Scope and features of magnetic particle testing

Magnetic particle testing is a highly accurate method for detecting discontinuities in ferromagnetic components. The sensitivity of this method is determined by the dimensions of discontinuities that can be picked up by this method. The magnetic field is able to indicate a discontinuity with a depth of 0.05 mm and a width of only 0.001 mm. This places it among the most accurate non-destructive techniques.

MT magnetic particle testing is one of the methods that identifies all inconsistencies in the material structure. In the case of welded joints, discontinuities and cracks can be identified. This method can also detect air bubbles inside castings and metallurgical products. In each of these cases, a slightly different field disturbance is created and therefore the arrangement of the magnetic powder will be different. Specialists will quickly assess the type of defect and its surface.

How to carry out MT magnetic-powder testing

The MT magnetic-powder test uses a white primer that is applied to the welded joint to be tested. This will form the background for the powder to be applied. The magnetic powder can be coloured or fluorescent. In the latter method, the test is slightly more efficient.

Despite the differences, each examination proceeds in a similar manner. Using magnetic heads, a field is generated that attracts the powder particles to itself. MT magnetic-powder testing is carried out in two forms. The longitudinal magnetisation method involves creating poles in the test piece between which field lines run. In circular magnetisation, on the other hand, a current is passed through a conductor in a hole inside the test piece. No poles are formed on the test piece and the field lines are inside the piece.

Assessment of the quality of the test material is based on observation of the stacking powder. The MT magnetic-powder test concludes with a comparison of the arrangement of powder particles on the material. Seeing differences in the arrangement is an indication that there are defects inside the material. Powder dispersion is evident at the welded joint defects, which is due to the dispersion and non-uniform passage of the field through the selected location.

Technic-Control Nondestructive Testing Laboratory – professional magnetic particle testing

MT magnetic-powder testing is quite simple to carry out, but only people qualified in non-destructive testing can read the results obtained in the right way. They also know the rules regarding the positioning of the field generating device in relation to the defects. If you want to be sure that MT testing is done correctly in your case, choose Technic-Control Nondestructive Testing Laboratory.

Why choose Technic-Control Nondestructive Testing Laboratory? The first argument for choosing our Non-Destructive Testing Laboratory is our qualified and experienced staff. Our specialists are certified to have gained the relevant qualifications. In addition, they are constantly developing by participating in courses and trainings. Employees of the Technic- Control Nondestructive Testing Laboratory have gained experience at many industrial facilities where they performed non-destructive testing. Knowing all the requirements and standards, we carry out magnetic particle testing in a fast way. We present the results obtained in an MT test report.

We carry out each magnetic test with high-quality test equipment. These are internationally respected devices with up-to-date technical tests. This not only allows us to perform the tests properly, but also to work even under difficult conditions.

We carry out MT magnetic testing of welded joints on behalf of large industrial plants and companies, as well as smaller enterprises. If you would like to find out more about our detailed offer, please contact the Technic-Control non-destructive testing laboratory customer service.