2. Contents
Terms & Definition
Types of Welds
Types of Joints
Weld Preparations
Types of Single Butt Preparation
Butt Welded Joint
Fillet Weld Profile
Effect of a Poor Toe Blend Angle
Summary of Terms
Duties of Welding Inspector
Responsibilities of Welding Inspector
Imperfections in Welded Joints
Mechanical Testing
Macro Inspection
3. A Weld:* A union between materials caused by heat,
and or pressure
A Joint:* A configuration of members
Text Page Ref 1:1
9. A butt welded butt joint*
A fillet welded butt joint*
A compound welded butt joint*
10. A fillet welded T joint*
A butt welded T joint*
A compound welded T joint*
11. A fillet welded Lap joint*
A spot welded Lap joint*
A compound welded Lap joint*
12. A fillet welded Closed Corner joint*
A butt welded Closed Corner joint*
A compound welded Closed Corner joint*
13. An inside fillet welded Open Corner joint*
C
An outside fillet welded Open Corner joint*
A double fillet welded Open Corner joint*
14. Weld Face*
Actual Throat Thickness*
Weld Width*
1.2.3.4. Weld Toes* Design Throat Thickness*
1 2
A
B 3 4
HAZ*
Weld Root*
A + B = Excess Weld Metal**
15. Vertical Leg Length*
Weld face*
Horizontal Leg Length*
Excess weld metal **
Design throat*
Actual throat*
16.
17. 6 mm
80°
Very Poor Weld Toe Blend Angle
3 mm*
20°
Improved Weld Toe Blend Angle
18. 90° 3 mm
Extremely poor toe blend, but excess weld metal is within limits*
19. Weld: A Union of materials
Joint: A Configuration of members
Weld Preparation: Preparing a joint to allow access and fusion.
Types of Weld: Butt. Fillet. Spot. Seam Plug. Slot. Edge.
Types of Joint: Butt. T. Lap. Corner (Open & Closed)
Types of Preparation: Bevel’s. V’s. J’s. U’s. Single & Double Sided.
Preparation Terms: Bevel/included angle. Root face/gap. Land/Radius
Weldment Terms: Weld face & root. HAZ. Weld toes.Weld width
Weld Sizing (Butts): DTT. ATT. Excess weld metal.
Weld Sizing (Fillets): DTT. ATT. Excess weld metal. Leg length *
20.
21. It is the duty of all welding inspectors:
To ensure that welding operations are carried out in
accordance with written, or agreed practices or
specifications
Before
*
During
After
22. Discuss the following
Before Welding:
1) Safety:
Rules.
2) Documentation:
Spec. Drawings. Procedures. Welder approvals. Certificates. Mill sheets
3) Welding Process and accessories:
Equipment,Cables, Regulators, Ovens etc
4) Incoming Consumables:
Materials/welding consumables (Size. Condition. Specification. Storage)
5) Marking out preparation & set up:
Method. Angles/Root face/gap values. Distortion control. Pre-heat prior to
tack welding if applicable*
23. During Welding:
1) Pre-Heating (Min 15 C as per UW-30 ASME Section VIII Div-I)
2) In process distortion control (Balance or sequence welding)
3) Consumable control. (Correct baking for E-7018 260-425 C and
storage 30-140 C prior to use)
4) Welding process (Related parameters i.e. volts/amps. gas flow rate)
5) Welding run sequence and inter-pass cleaning
6) Minimum/maximum Inter-pass temperatures (150 C for SS, 250 C
for CS.
7) Full compliance with all elements given on the WPS*
24. After Welding:
1) Visual Inspection
2) Non Destructive testing
3) Repairs*
4) Repair procedures (NDT/Welding/Welder approval)
5) PWHT
6) Hydro-static testing
7) Submission of all inspection reports to QC departments*
25. To Observe Activities &
Imperfections*
To Record Activities &
Imperfections*
Activities &
To Compare
Imperfections*
26. A Welding Inspectors toolbox should contain*
A welding gauge (Cambridge style, or high low gauges etc)
A tape measure and scale
A wire brush
A magnifying glass
A torch and mirror
A specification, pen and report, or note paper
27. Welding imperfections can be categorized into groups:
1) Cracks
2) Gas Pores & Porosity
3) Solid Inclusions
4) Lack of fusion
5) Profile & Lack of Filling
6) Mechanical or Surface damage
7) Misalignment*
28. A HAZ hydrogen crack, initiated at the weld toe
Most cracks are initiated from stress concentrations *
29. Surface breaking porosity
Shrinkage cavity*
Coarse cluster porosity
Fine cluster porosity
Blow hole > 1.6 mm Ø
Hollow root bead An isolated internal porosity
30. Surface breaking solid inclusion
Internal solid inclusion causing
a lack of inter-run fusion* Internal solid inclusion causing
a lack of sidewall fusion
Internal solid inclusion Solid inclusions caused by
undercut in the previous weld
run
31. Lack of sidewall fusion &
incompletely filled grove*
Overlap (Causing cold laps)
Lack of inter-run fusion Lack of sidewall fusion
Lack of root fusion
32. Spatter An Incompletely filled groove
A
Lack of root fusion
Bulbous, or irregular contour
Arc Strikes
Poor toe blend
B
Incomplete root penetration
*
33. Root Run or “Hot pass” undercut
Parent metal, surface undercut
Weld metal, surface undercut*
35. Any surface damage caused by:
Grinding
Hammering/chisel marks
Slag chipping hammer marks
Arc strikes
36. Linear
Excess weld metal height
Lowest plate to highest point
3 mm
Linear misalignment measured in mm (over 13mm to 19mm
as per UW 33 of ASME Sec VIII Div-I)
Angular
15°
Angular misalignment measured in degrees*
37. Why ?* To establish the level of mechanical properties*
properties
Which properties ?*
1) Hardness*
2) Toughness (Impact Test)*
3) Tensile strength*
4) Ductility*
38. We test welds to establish minimum levels of mechanical
properties, and soundness of the welded joint*
We divide tests into Quantitative & Qualitative methods:*
1) Quantitative tests:
1) Quantitative tests: (Have units)*
(Have units)*
2) Qualitative tests:
2) Qualitative tests: (Have no units)*
(Have no units)*
40. The specimen below has been polished and is
ready to be hardness tested
= Hardness Survey
Thickness
Base metal HAZ Fusion boundary Weld metal
41. Generally we use a diamond or steel ball to form an indentation
We measure the width of the indentation to gauge the hardness*
42. 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 diamond
depending on the scale*
43. Machined notch 10 x 10 mm
The specimen may be tested from different areas of the weld.*
Graduated scale Pendulum Hammer
of absorbed
energy in Joules*
Location of specimen
44. 1) Charpy V test: 10 x 10 (Specimen horizontal) Joules*
2) Izod test: 10 x 10 (Specimen vertical) Ft.lbs*
45. Radius
(For radius reduced test specimens only)
Weld
Test gripping area HAZ
Direction of test
Plate material Reduced Section
Used to assess the tensile strength of the weld metal
46. All Weld Metal Tensile Testing
Direction of the test *
Tensile test piece cut
along weld specimen.
47. Firstly, before the tensile test 2 marks are made 50mm
50 mm
During the test, Yield point & Tensile strength are measured
The specimen is put together and the marks are re-measured
75 mm
A new measurement of 75mm will indicate Elongation E50 %*
48. 1) Excess Weld Metal Height 7) Poor Toe Blend*
6)Porosity
2) Lack of Sidewall Fusion
5) Root Penetration
3) Lack of Root Fusion
4) Slag inclusion & Lack of inter-run fusion
49. Bend tests are used to establish fusion in the area under test
Guide A Guided root bend test*
Lack of root fusion shown here*
Former
Test Piece
Force
Further tests include face, side and longitudinal bend tests*
For material over 12 mm thickness, side bend test may be
used*
51. The main difference between Macro & Micro is that Micro is
the study of the micro-structure at much higher magnification
The limit of Macro inspection is magnification < X 10
The specimen is usually cut from a stop/start in the test piece
52. Remember! The process of inspection is to first:
Observe, then Report, then Compare!*
