Fabrication and Quality Control of structural steel

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2. Fabrication definition
Fabrication is the second main process in steel lifecycle
after production from mills.
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3. Difference bet. Q.C & Q.A
Quality control: activities used to fulfill requirements
for quality. (ex: calibration)
“Quality control is a process for maintaining standards
and not for creating them.”
Quality assurance: activities that do not control quality
but establish the extent to which quality will be.(ex:
statistical control)
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4. Main raw materials
 Standard sections
 Plates
 Fasteners
 Weld electrodes
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5. Main procedures
• Receiving ,
storage,
identification and
traceability of raw
materials.
• Preparation of
material.
• Production.
• Surface
preparation &
protection.
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6. 1.Receiving , storage, identification
and traceability of raw materials
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7. 1.Receiving , storage, identification
and traceability of raw materials
Color Coding Printed Heat
No.
Hard Stamp
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8. 2.Preparation of material
Material is prepared for bolting (in site) or welding (in
next stage) by:
 Cutting of steel elements.
 Edge preparation.
 Holes drilling or punching.
 Rolling of plates.
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9. 2.Preparation of material
Hole Punching Hole Drilling
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10. 3.Production
 Cold forming: using bend machine
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11. Welding (main process)
Factors affecting quality of weld:
1-Proper electrode
2-Welding apparatus
3-Welding method
4-Welding position
5-Edge preparation
6-Control of distortion
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12. Welding (main process)
Possible defects in weld:
1-Lack or incomplete fusion.
2-Inadequate edge preparation.
3-Porosity and gas pockets.
4-Undercut.
5-Slag inclusion.
6-Cracks.
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13. Non-destructive tests
Radiography test(RT): used for small thicknesses to show the defects
inside weld .It uses x-rays and gamma rays.
Ultrasonic test (UT): using ultrasonic waves, used for large thicknesses,
it’s faster and easier for judgment and need one technician to be carried
out but it needs a certified and qualified technician.
Magnetic Test (MT): using magnet to identify subsurface defect up to 6
mm below surface for A.C current or up to 4 mm below surface for D.C
current.
It must be used with materials that have magnetic properties.
Dye penetrant test (PT): used for identifying surface defects or
subsurface but open to surface.
As red spot gots wider as defect is deeper.
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14. MT device Plan of weld
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15. 4.Surface preparation &
protection
Methods of preparation:
-Wire brush (manual or automatic)
-Blasting using : - Sand
- Marble
Methods of protection:
-Painting: primer layer followed by another epoxy layer
-Galvanization: for higher protection requirements
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16. Refrences
 Egyptian code of practice for steel construction and
bridges.
 AISC structural steel building specifications.
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