8/22/2019 Non Destructive Examination
1/23
Non Destructive Examination
(NDE)
8/22/2019 Non Destructive Examination
2/23
Non Destructive Examination
(NDE)
Non Destructive Examination is the act of
evaluating a welded component (or material to
be welded) without affecting the serviceability
of the part or material.
8/22/2019 Non Destructive Examination
3/23
NDE
All Welds have flaws.
Another name for a flaw is a discontinuity
Discontinuities are interruptions in the
normal crystalline structure (or grain) of
the metal.
Discontinuities are NOT always defects
8/22/2019 Non Destructive Examination
4/23
NDE
The purpose of welding inspections is to
locate and determine the size of any
discontinuities
Discontinuities that are to large or repeat
too often within the weld become defects
Defects will compromise the welds overall
strength
8/22/2019 Non Destructive Examination
5/23
What are some common defects?
Porosity
Undercutting
Rollover or Cold Lap
Slag inclusion
Poor penetration Voids
Hydrogen Embrittlement
8/22/2019 Non Destructive Examination
6/23
Typical faults in a finished weld.
8/22/2019 Non Destructive Examination
7/23
How would you find these faults ?
Non Destructive Examination
NDE
8/22/2019 Non Destructive Examination
8/23
Common methods used in NDE
Visual Inspection (VT)
Magnetic Particle Inspection (MT)
Liquid (Dye) Penetrant Inspection (PT)
X-Ray inspection (RT)
Ultrasonic testing (UT) Air or water pressure testing (LT)
8/22/2019 Non Destructive Examination
9/23
Visual Inspection (VT)
Visual is the most common inspection
method
VT reveals spatter, excessive buildup,
incomplete slag removal, cracks, heat
distortion, undercutting, & poor penetration
Typical tools for VT consist of Fillet gauges
Magnifying glasses, Flashlights, & Tape
measures or calipers.
8/22/2019 Non Destructive Examination
10/23
Visual Inspection (VT)
Fillet gauges measure
The Legsof the weld
Convexity (weld rounded outward)
Concavity
(weld rounded inward)
Flatness
8/22/2019 Non Destructive Examination
11/23
Magnetic Particle Inspection
(MT)
Magnetic Particle Inspection (commonly referred
to as Magnaflux testing) is only effective at
checking for flaws located at or near thesurface.
MT uses a metallic power or liquid along
with strong magnetic field probes to locateflaws. (Particles will align along voids)
MT can only be used on materials that can
be magnetized
8/22/2019 Non Destructive Examination
12/23
Liquid (Dye) Penetrant
Inspection (PT)
Liquid penetrant inspection uses colored or
fluorescent dye to check for surface flaws.
PT will not show sub-surface flaws.
PT can be used on both metallic and non
metallic surfaces such as ceramic, glass,
plastic, and metal.
PT dose not require the part to be
Magnetized.
8/22/2019 Non Destructive Examination
13/23
X-Ray inspection (RT)
Welds may be checked for internal discontinuities
my means ofX- Rays
AnX-Ray is a wave of energy that will passthrough most materials and develop the negative
image of what it passes through on film.
A Radiograph ( X-Ray picture) is a permanent
record of a weld used for quality inspectionpurposes
RT inspections can reveal flaws deep within a
component
8/22/2019 Non Destructive Examination
14/23
Ultrasonic testing (UT)
Ultrasonic testing (UT) is a method of
determining the size and location of
discontinuities within a component usinghigh frequency sound waves.
Sound waves are sent through a transducer
intothe material and the shift in timerequire for their return or echo is plotted.
Ultrasonic waves will not travel through air
therefore flaws will alter the echo pattern.
8/22/2019 Non Destructive Examination
15/23
Air or water pressure testing
(LT)
Pressure testing or leak testing can be
performed with either gasses or liquids.
Voids that allow gasses or liquids to escape
from the component can be classified as
gross (large) or fine leaks.
Extremely small gas leaks measured in
PPM (parts per million) require a Mass
Spectrometer to Sniff for tracer gases
8/22/2019 Non Destructive Examination
16/23
Quiz time
True or False ?
Dye penetrate inspections can only be used
on non magnetic material.
Answer: False
8/22/2019 Non Destructive Examination
17/23
Quiz time
True or False ?
X-Rays can only be used to locate flaws at
or near the surface of a weld.
Answer: False
8/22/2019 Non Destructive Examination
18/23
Quiz time
True or False ?
Virtually all welds have flaws.
Answer: True
8/22/2019 Non Destructive Examination
19/23
Quiz time
True or False ?
Magnetic particle testing can only detect
flaws at or near the surface.
Answer: True
8/22/2019 Non Destructive Examination
20/23
Quiz time
True or False ?
Magnet particle testing can only be done on
materials that can be magnetized.
Answer: True
8/22/2019 Non Destructive Examination
21/23
Quiz time
The letters NDE Mean ___________ ?
A: nondestructive inspection
B: nondestructive evaluation
C: nondisruptive evaluation
D: nondestructive examination
8/22/2019 Non Destructive Examination
22/23
Quiz time
The method most often used to check for leaks as
small as one part per million (PPM) from a gas
line or cylinder is the _________ Method ?A: hydrostatic
B: mass spectrometer
C: soap suds bubbleD: scleroscope
8/22/2019 Non Destructive Examination
23/23
Modern WeldingYork County School of Technology
Top Related