Monitoring of corrosion rate in oil and gas pipes :
Corrosion of pipes and industrial installations always impose a huge cost on the infrastructure of the world today, so the rate of destruction of these infrastructures and installations must always be monitored, monitored and tested. Non-destructive testing plays an important role in the testing and inspection of industrial components and installations. The Eddy Carnet method has always been considered and researched. The feasibility of using this method in fluid transfer tubes is due to its ability to measure different properties of the coating and no need for physical contact with the pipe wall. They are a very important advantage that has made this method more popular. On the other hand, this method does not just end up being tested on the tube and not on the cover, and this method is also used to troubleshoot inside the tubes.
The basis of the eddy current method is that if we pass an alternating current through an electrical conductor, the magnetic field is created inside and around the conductor. The field created in this case will be related to the frequency of current and potential passed through the coil and the magnetic field will change accordingly. If another conductor cuts off the field, an alternating current is called the eddy current. This current generates a secondary magnetic field that counteracts the primary field generating the eddy current. This process is the basis of Eddie Carnet’s postcard. The amount of field contact generated by the primary winding is directly related to the impedance and inductance of the secondary winding, in fact to any changes in the component such as microstructure change, thickness, chemical composition, stress in the component, etc., impedance and inductance characteristics of the wire. The secondary screw changes and therefore the amount of secondary induction changes. By examining and analyzing this induction obtained by the secondary coil, one can infer the particularities of the segment in question.
In Eddie Carnet’s method, the voltage is used as a wave and enters the segment by the primary winding, so the shape of the wave is very important. The use of the sine wave in the Eddy-Carnet method is very common and many researchers have tested their samples using this wave. It is very efficient to use, but its depth of penetration is low within the subsurface testing range. But the latest research in the world has been done with Eddy Carnet with a square pulse. The use of a square wave because of its higher penetration power enables the Edicarnet method to test and test more depths in the components. For example, in the corrosion measurement of sheets, Alamin et al., Used this method to corrode simple carbon steel sheets with different coatings to investigate the amount of coating degradation and the amount of corrosion in uncoated samples.