Page 92 - Quick Guide to Welding and Weld Inspection by S.E. Hughes, Clifford Matthews

Non-destructive and Destructive Testing

Figure 6.6 Tensile specimen: reduced section transverse
test

Tension tests
The main objective of a tension test on a welded joint is to
measure the yield and tensile strengths of the sample under
test. A pulling force (load) is applied to the sample and the
yield and ultimate tensile strength (UTS) are measured and
recorded on the test form along with the material type,
specimen type, specimen size and location of the fracture.
Weldments are normally subjected to a reduced transverse
tensile test (see Fig. 6.6).
Manufacturers of welding consumables carry out a long-
itudinal ‘all weld metal’ tensile test to measure the tensile
strength, yield point and percentage elongation (E%) of the
deposited weld metal. The sample is taken from the centre of
the weld and consists of weld metal only.
Bend tests
Bend tests give an indication of weld quality and a rough
indication of ductility by putting the weld and HAZ under
tension. The weld and HAZ must be included within the bent
portion and a limit given to the size of linear openings
permitted on the surface under test. Bend tests are normally
transverse tests taken across the weld and include the weld,
HAZ and base material. Longitudinal tests are more unusual
but can be used where dissimilar base materials with widely
differing properties are welded or where the weld metal is of
greatly differing properties to the base metal. Guided bend
tests are those that have the sample bent into a guide (see Fig.
6.7).

77

Woodhead Publishing Ltd – A Quick Guide to Welding and Weld Inspection
Data Standards Ltd, Frome, Somerset – 17/9/200906QG Welding chap6.3d Page 77 of 87