Page 109 - SSAB Welding Handbook Edition 2

©2009-2019 by SSAB Group of companies (SSAB). All rights reserved. Only digital PDF file. No distribution. No printing allowed!
No part of this handbook may be reproduced in any form or by any means without permission in writing from SSAB.
Welding handbook 18.0 Non destructive evaluations

At conventional inspections the probe is first moved A development of the conventional ultrasonic
transverse to the direction of the joint in order to technique is the phased array technique. With this
©SSAB
inspect its complete cross section. This procedure is technique the probe can sweep the inspected area
repeated along the entire joint. Detection of rounded with different search angles continuously, according
and oval shaped discontinuities is, in general terms, to fig. 18.9, which means that the inspection is more
relatively easy since these shapes are favorable for efficient.
ultrasonic waves to strike. Linear discontinuities need
more arrangement to identify. This is because the
closer to a right angle the ultrasonic wave is when it
strikes the discontinuity, the easier it is for an echo
to be established. A complete evaluation of a joint,
therefore, involves inspections with different search
angles. Frequent search angles are in the range of 20° D
35º-70º as well as 90º.

The UT inspection is finalized by removing the
couplant from the work piece. Fig. 18.9: Inspection with a phased array technique. The transmitted
ultrasound is illustrated.

This handbook contains general suggestions and information without any expressed or implied warranty of any kind. SSAB hereby expressly disclaims
all liability of any kind, including any damages, in connection with the use of the information and for their suitability for individual applications. 109
It is the responsibility of the user of this brochure to adapt the recommendations contained therein to the requirements of individual applications.