Magnetic control of pipes
High quality finished products, improved workflow safety and increased machine uptime are factors of paramount importance in today’s manufacturing processes.
An important criterion for the successful operation of the enterprise is the absence of unacceptable equipment defects, which means that it is necessary to regularly monitor the condition of all parts.
Magnetic control is a check of the state of metal structures based on certain physical phenomena associated with the magnetism of materials. For example, if a structure made of ferromagnetic material has any defects, then when magnetized, it will dissipate the created magnetic field. That is, in the presence of defects, a magnetic flaw detector will detect distortion or interruption of magnetic field lines.
Where is magnetic control used?
Magnetic flaw detection is used in production in the processes of casting, forging, cold and hot stamping, machining and welding. Monitoring of the state of metal products (especially heating surfaces of pipelines) is best done using magnetic flaw detection.
Typical defects detected using this method:
- cracks;
- voids;
- Porosity;
- Lack of fusion, inclusions;
- Tears resulting from metal fatigue or due to mechanical stress;
- Corrosion.
The inspection process itself consists of three stages:
- magnetization of the object;
- Application of an indicator containing magnetic particles;
- Evaluation of the result.
Magnetization is usually carried out using portable or stationary flaw detectors using direct or alternating current, depending on the task. The current creates a magnetic field that penetrates deep into the metal, so that defects located 3-5 mm below the test surface can be detected. If there is a defect in the area under study, the thickening of the powder is easily traced. The pattern formed during the check is the structure of the defect. From the drawing, you can determine the exact location and size of the defect in the metal.
The final stage is the evaluation of the results, which make it possible to determine the size of the defect and its depth. The assessment should be carried out by a highly qualified specialist, since the identification of a defect depends on various factors such as shape, direction, orientation, etc.