The irreversible changes of magnetization in zones of stress concentration are appearing inside the steel components of machines and structures when they are working under variable loads (cyclic or vibration). As is well known, the existence of such zones causes and accelerates the processes of parts destruction, such as corrosion, cracking, fatigue or creep.
Owned measuring system enables the evaluation of the state of stress of structures and machine parts. It is possible by the use of passive, magnetic, non-destructive diagnostic method by the measurement of stress-strain state of the material, based on the record and analysis of the distribution of the magnetic fields. This allows a precise location of stress concentration areas, which are potential sources of fatigue damage. It is also possible to determine the actual state of fatigue of the part and the detection of existing cracks and other defects in the structure of the material. This is a diagnostic method, which allows to relatively quickly determine the areas of metal defects in new products and also to detect with high accuracy a failure in the operating devices. That allows to take appropriate preventive actions.
The examination of the devices by the metal magnetic memory method shortens the diagnosis and repairs time. It is possible the fast location of the areas that should be further tested by other methods (eg. with ultrasonic method). The method does not require the magnetization of the element or special preparation of the surface of the test, which predisposes it to welds testing.