3- welding destructive tests
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Hardness:*
Toughness:* The ability of a material to absorb impact energy
Tensile strength:* The ability to resist the action of a pulling force
Ductility:* The ability to deform plastically under tension*
The ability of a material to resist indentation
Mechanical Properties
We test welds to establish minimum levelsof mechanical properties, and soundness ofthe welded joint*
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The specimen below has been polished and isready to be hardnesstested
= Hardness Survey
Further hardness surveys may be taken as the thicknessof the specimen increases*
Thickness
Hardness Testing
Base metal HAZ Fusion boundary Weld metal
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Generally we use a diamond or steel ball to form an indentation
We measure the width of the indentation to gauge the hardness*
Hardness Testing
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1) Vickers Diamond Pyramid: Always uses a diamond*
2) Brinell hardness test: Always uses a steel ball*
3) Rockwell hardness test: Uses a ball, or diamonddepending on the scale*
Hardness Testing
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10 x 10 mmMachined notch
Pendulum Hammer
Location of specimen
The specimen may be tested from different areas of the weld.*
Graduated scale
of absorbedenergy in Joules*
Charpy Toughness Testing
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Transverse reduced test piece*
A Section of weld is cut, or machined out across the test pieceand tested in tension to failure. The units are usually in N/mm
Transverse Tensile Test
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Bend tests are used to establish fusion in the area under test
Former
Test Piece
Lack of root fusion shown here*
Force
A Guided root bend test*Guide
Bend Tests
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Bend Tests
Specimen prior to test* Specimen after test*
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Saw cutHammer blow
Full fracture
Any strait line indicates aLack of root fusion*
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3
1
Fracture line
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2
3
Inspect both surfaces
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2 3
Line of fusion
Fillet Weld Fracture Tests
X
Y
X
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A
B
Inclusions on fracture line*
C
Lack of root penetrationor fusion
Hammer blowSaw Cuts
Fracture line
Inspect both surfaces
Butt Nick Break Tests