Method for checking crack defects on weld junctions of specimens, in particular on welding seams of underwater structural elements made from metal, using the magnetic powder method, and device for carrying it out

摘要

In this method, the specimen or a weld junction is both magnetised and bathed in a carrier liquid containing suspended metal particles, and the carrier liquid is circulated. In this process, a continuous circulation of the carrier liquid containing the metal particles is carried out in the feed line itself, and for this purpose the feed line has at least two independent lead elements, e.g. two lead hoses for the carrier liquid, while on the other hand the circulation itself is carried out only in a sub region of the feed line, in particular upstream of the control region.