Page 94 - Quick Guide to Welding and Weld Inspection by S.E. Hughes, Clifford Matthews

Non-destructive and Destructive Testing

Figure 6.8 Types of bend test
particularly accurate test but can give a general indication of
the ability of a material to resist brittle fracture at its
minimum design material temperature. The test consists of
holding a machined specimen, of a specified size (normally
55 mm 10 mm 10 mm) containing an accurately
machined notch of specific dimension, at both ends as a
simple beam. A pendulum impacts on the specimen and the
start and finish heights of the pendulum are measured. The
difference in height equates to the energy absorbed by the
specimen before it fractures. This absorbed energy is usually
measured in joules on a scale attached to the machine.
Three Charpy specimens are tested at each specified
temperature and the final result taken as an average of the
three. Tests can be done at various temperatures and
recorded in a graph to form the Charpy curve (see

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Woodhead Publishing Ltd – A Quick Guide to Welding and Weld Inspection
Data Standards Ltd, Frome, Somerset – 17/9/200906QG Welding chap6.3d Page 79 of 87