NS-40 Manual
Page 4
729-110-036
Revision 1.14
August 2013
WELD INSPECTION
Steel
Visual Inspection
Visual inspection is dependent upon the interpretation
of the appearance of the welded end of the stud. To
assist you, Figure 4 shows examples of various welds
with proper interpretation.
Physical Inspection
If, after visually inspecting the welds, a questionable
weld is evident, the weld should be physically tested.
Initial weld setups should also be physically tested.
Suggested physical tests are as follows:
1.
Bend Test - Stud to be tested shall be bent away
from its vertical axis 90º or until failure. Failure
should occur in the stud proper, or, on thin plate, a
full stud diameter plug of base metal should be torn
out.
2.
Torque Test - Stud shall be torqued until a pre-
specified loading is attained or until the stud fails
or, on thin plate, a plug of the base material should
tear out.
Normal Stud Weld
Stud hangup.
Check
setup of gun. Refer to
page 2.
Hot weld.
Check weld
setup. Refer to page 2.
Cold weld.
Check weld
setup. Refer to page 2.
Figure 4
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Aluminum
Visual Inspection
Visual inspection of aluminum stud welds is not
conclusive since the appearance of the weld fillet is not
necessarily an indication of a good or bad weld.
Visual inspection of aluminum stud welds is
recommended only to determine complete fusion and
absence of undercut around the periphery of the weld.
Physical Inspection
Physical test procedures for inspecting (magnesium-)
aluminum alloy studs are:
1.
Bend Test -The stud to be tested shall be bent, using
a bending tool as shown in Figure 5, approximately
15° away from its vertical axis before the stud
breaks in the weld shank or the base material fails.
Note:
Do not bend aluminum studs by striking with a
hammer; always use a bending tool as shown.
2.
Torque Test -The stud to be tested shall be torqued
in the conventional manner by applying torque until
the stud fails or a predetermined torque load is
reached.
Figure 5
Recommendations
Before starting any stud welding operation, or after
the equipment has remained idle for a period of
time, trial or test studs should be welded to a plate
for testing. Testing should continue until there is
no failure of a test stud.
