Welding process introduction
Prepared by: DSc PhD Dževad Hadžihafizović (DEng)
Sarajevo 2024
Basic welding knowledge
Abbreviation
Abbreviation Full Name
AW Arc Welding
FCAW Flux cored arc welding
GMAW =(MIGW/MAGW) Gas Metal Arc Welding
MIGW Metal inert gas welding
MAGW Metal Active Gas Welding
GTAW=TIGW Gas Tungsten Arc Welding
TIGW Tungsten Inert Gas Welding
SMAW Shielded Metal Arc Welding
SAW Submerged Arc Welding
FW Flash Welding
PAW Plasma Arc Welding
Welding Processes
Arc Welding MIGW：（Ar& Pulse
Helium & mixed MIG
gases）Metal
Inert Gas
Welding Non Pulse MIG
GMAW Solid Wire
Pulse MAG
MAGW：
Active gas
(CO2) Non Pulse MAG
FCAW: CO2
Flux cored
FCAW Ar+CO2 mixed
wire gases
GTAW(TIGW) Solid wire Argon gas
-Solid wire
SAW -Flux cored Flux
wire
Arc welding- including SMAW, GMAW,MIG,MAG
SMAW: Shielded Metal Arc
Welding
GMAW: Gas Metal Arc Welding
MIGW (Metal Inert Gas Welding):
Ar or He
MAGW (Metal Active Gas
Welding): Ar or He+ O2or CO2
Example of product welding type
GMAW: Gas Metal Arc Welding
Gas Metal Arc Welding: Ar(80%) + CO2(20%) (This is almost nearly MAGW) 12
Double V welding- Stamped wheel
Example of product welding type
Single V welding- Stamped wheel
13
Example of product welding type
Lap joint fillet welding- Stamped wheel
Product validation requirement
1. Dimension: welding size(weld leg length, Z; weld throat thickness, a)
2. Section check: welding size, macro etching, penetration, crack,
tensile, bend test
3. welding quality- internal: porosity, slag inclusion, lack of fusion
4. welding quality- appearance: porosity, welding slag, underfill, crack,
undercut, overlap, crater
Standards on welded product validation
Camso Spec for welding :
9S-1019：This specification covers the engineering requirements of welds, welding materials, and welders. It also defines welding
imperfections and sets minimum weld quality requirements for joining metals using arc welding processes.
9S-1018：This material is used in the manufacturing of welding of an ATV/UTV products. specifies the quality criteria for welded joints and
explains what is not acceptable and what is anticipated as quality on a welded product.
International spec:
AWS D1.1 / D1.1M : 2008: Structural Welding Code – Steel
AWS D14.3/D14.3M:Specification for Welding Earthmoving, Construction and Agricultural Equipment.
Construction & Material Handling BUs: ISO 3834-2 (under that ISO 15614-1, 15614-13 etc)
Dimension- welding size
Groove welds in butt joints: The height of weld reinforcement shall not exceed 3mm for a joint
or weld sizes up to and including 50mm. The weld reinforcement of weld size over 50mm shall
not exceed 5mm, as shown in figure below.
In case of wheels with groove welds exposed to rubberizing (default), a maximum of 1mm
reinforcement is allowed. Groove welds on wheels not exposed to rubber will be indicated as
Dimension- welding size
Construction & Material Handling BUs cover this under, ISO 6520-1 & ISO
6520-2
Quality level – As per ISO 5817-B
Acceptance criteria – As per ISO 5817-B
FILLET WELDS::
Dimension- welding size
Fillet weld leg size shall conform to the following tolerances based on a measurement of fused
leg length:
Weld size under 10mm: +3mm, -1mm.
Weld size 10mm and over: +3mm, -1.6mm.:
Welding quality- internal
Three dimensional-type discontinuities. Permissible in discontinuous
distribution, provided the largest dimension of any single discontinuity does
not exceed the following:
-20% of the weld size or joint penetration for weld size of 10mm and under.
-15% of the weld size or joint penetration for weld size over 10mm.
The sum total of the porosities greater dimension shall not exceed 10mm
in any 25mm of linear length of weld, nor 10% of the weld length.
Welding quality- internal
Underbead Cracks: Not permissible.
Welding quality- internal
Planar-type discontinuities (lack of fusion, slag inclusions, or fissures)
Permissible to 25% of specified weld size, or less than 25% of the joint penetration in height or width. The length of an
individual discontinuity, or the sum of discontinuities, shall not exceed 10% of the weld length for up to 180mm of weld.
Welding quality- internal
Lack of fusion
Slag inclusion
Crack/fissue in weld bead
Welding quality- Appearance
Porosity: The sum of diameters of visual or surface porosity, including piping porosity, shall not exceed 10mm in
any 250 mm length of weld, with no single void exceeding 1.0mm in diameter, regardless of the fillet size.
Welding quality- Appearance
underfill:
Groove welds underfill in butt joint: For material thickness above 9mm: Shall not exceed 1mm. For material
thickness of 9mm or less;
Double groove weld: Weld section shall not have combined weld underfill exceeding 10% of total section thickness.
Shall not exceed 10% of material thickness.
In all cases, the length of the underfill allowed shall not exceed 50% of the total weld length.
Welding quality- Appearance
Weld overlap: Shall not exceed 1.6mm beyond the fusion line of the weld.
Welding quality- Appearance
Craters: Not permissible. Shall be filled to at least 85% of the full
cross section of the welds..
Welding quality- Appearance
Cracks: No cracks in the welds or in adjacent base metal surfaces
are allowed.
Undercut:
For material thickness to and including 6mm: Shall not exceed 10% of material thickness.
For material thickness greater than 6mm: shall not exceed 1mm. In addition, 1.6mm undercut depth up to
25mm continuous length in any 300mm weld length is permissible; the accumulative length is not to exceed
38mm in the same 300mm length.
Welding requirement list
WPS and WPQR
• Preliminary Welding Procedure Specification: set up the welding parameter.
PWPS
• Welding Procedure Quality Record: make the penetration, tensile,bending
WPQR test and record it.
• Welding Procedure Specification: finalize the parameter again based on
WPS WPQR
Example for WPS and WPQR:
Example for RT report
Micro Tech report – weld size test report, Penetration
Micro Tech report – tension test report size
Supplier Expectations
Review each “note” and “dimensions” from drawing for concerns
Prepare Measurement Agreement before DPAR
Set up welding requirement list before DPAR
Make PWPS after DPAR
Define which WPQR need to be done by 3rd party.
Ensure welder and welding engineer be certified
Define inspection method, facility and frequency
Make the WPQR after P3 samples completed
Finalize WPS after WPQR be approved by CAMSO
Assist CAMSO to do self audit based on Welding check list
