Hard Spots are localised areas where the hardness exceeds the designated value.
Hard spots occur on the plate surface being caused by variations in the casting and TMCP processes of plates manufacture.
Being invisible to the conventional UT or X-ray techniques, Hard Spots may result in microcracks in the pipe production process. Those microcracks, developing in the pipelines, destroy them, resulting in incidents or even explosions.
Since there have been several pipeline incidents related to hard spots in recent years, the issue has drawn a lot of attention and new regulations for plates/pipes makers have appeared.
It is well known, that even the conventional EC-sensors based technique can be sensitive to hard spots. However, the conventional EC-technique is also extremely sensitive to variations of lift-off, rolling scale on the plate surface, residual magnetization, etc. – the industrial factors that substantially reduce the efficiency of the conventional EC-technique or even make its application impossible.
NORDINKRAFT has developed and patented a unique method and respective hard-and-software, that allows one to perform an extremely reliable automatic examination of plates for hard spots in severe industrial environment.
This method is based on a very sophisticated multifrequency analysis of signals, provided by so called “PEC probes”, specially designed by Nordinkraft for the above task.
NORDISCAN-HS can detect hard spots of 10mm x 10mm and bigger on steel plates, with almost no untested zones at edges. The automatic test can be carried out on-line and off-line. A special trolley controlled by operator will be available soon as well.
It is not necessary to demagnetize the plates prior to their examination. NORDISCAN-HS effectively supresses the influence of the magnetic crain transporting the plates to the test area. Residual magnetization does not affect test results. It means, demagnetization of plates prior to the test is not required.
The best reference is a satisfied customer who is going to present the use of the new technology based on NORDISCAN-HS at the international exhibition ADIPEC 2023 (10/2-5) in Abu Dhabi. AL GHARBIA PIPE COMPANY’s booth is at Hall 10, stand number 10860.