33 صفحه pdf
EN ISO 5817:2014
Welding - Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded) - Quality levels for imperfections
{تخصصی بازرسی فنی}--12 صفحه--محصول 2012--لینک دانلود رایگان-->>
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Abstract
A reliable Non-Destructive Testing approach is required for the inspection of polyethylene (PE) butt fusion
joints in various material grades and pipe sizes. The nature of butt fusion joints is that the fusion zone is
relatively small and the inspection solutions are often restricted by the existence of an external weld bead. This
weld bead restricts the probe placement and the probe needs to be positioned in a non-optimal position for the
weld inspection. The PE material grades have low velocity and high frequency dependent attenuation, which will
complicate the inspection of thicker pipes. In this paper, phased array ultrasonic techniques are presented and
their capabilities are evaluated. The techniques utilise customised water wedges to be able to generate forward
angle beams to cover the weld within the PE pipe. Techniques have been developed for pipes with outer
diameters between 220-710mm and thicknesses between 14-45mm. Probe and wedge parameters have been
optimised for this range of pipes. The capability of detecting circular defects with diameters between 1.5-8mm
on pipes with an outer diameter between 220-710mm using a phased array ultrasonic inspection solution, and the
challenges overcome when working with this type of material, are presented.