Community Research and Development Information Service - CORDIS

Magnets reveal defects

To ensure continuous and secure use of metallic constructions, all defects, even the ones that are hidden, should be quickly detected and repaired. Magnetic defectoscope MKD-1 can reveal, non-destructively, defects such as cracks and corrosion, regardless of their location.
Magnets reveal defects
Big metallic constructions are utilised by almost all business sectors. These constructions are characterised by high durability and resistance to corrosion. They are often placed for long periods of time in extreme environmental conditions, being part of production or transportation activities. (Pipelines and platforms are indicative examples). Their weak points and defects, such as corrosion and cracks, should be localised and repaired in order to prevent a possible brake down of the construction.

Magnetic defectoscopy is an indirect non-destructive method, which is based on the magnetism and behaviour of metals when they interact with magnetic fields. This method can reveal the defects of metallic parts even in cases where these defects are not accessible or visible, like the inner part of a pipeline or underneath the surface of the metal.

A team at the Tomsk Polytechnic University developed a device that is based on the above method named defectoscope MKD-1. It consists of a set of parts such as articulated magnetic defectoscope, pole pieces, aerosol set for sprayed materials and reference patterns. All these parts are used to control the distribution of the magnetic field on the metallic part. In places where defects exist, magnetic leakages appear and the distribution of the magnetic field is irregular. These irregularities reveal not only the location of the defect but its nature as well (e.g corrosion, crack etc). MKD-1 has the advantage to use permanent magnets instead of electric powered ones. This characteristic makes it independent of energy supply, easily portable and able to work in aquatic conditions.

It is commonplace that prevention is better than treatment. MKD-1 provides a secure means for the early identification of defects to avoid costly brake downs and maintenance work.
Record Number: 80745 / Last updated on: 2005-09-18
Domain: Industrial Technologies