There are many types of materials used to produce welds. These welding
materials are generally categorized under the term filler metals, defined
as "the metal to be added in making a welded, brazed, or soldered joint."
The filler metals are used or consumed and become a part of the finished
weld. The definition has been expanded and now includes electrodes
normally considered non-consumable such as tungsten and carbon electrodes,
fluxes for brazing, submerged arc welding, electroslag welding, etc.
The term filler metal does not include electrodes used for resistance
welding, nor does it include the studs involved in stud welding.
The American Welding Society has issued 26 specifications covering filler
materials. This table also shows the welding process for which each
specification is intended. These specifications are periodically updated
and a two-digit suffix indicating the year issued is added to the
specification number. Additional specifications are added from time to time.
| Table 1. AWS filter metal specification and welding processes. |
| AWS Specification |
Specifications Title |
for process shown bellow |
|
OAW
|
SMAW
|
GTAW
|
GMAW
|
SAW
|
Other
|
|
A 5.1
|
Carbon steel covered arc-welding electrodes
|
|
X
|
|
|
|
|
|
A 5.2
|
Iron & steel gas welding rods
|
X
|
|
|
|
|
|
|
A 5.3
|
Aluminum & aluminum alloy arc welding electrodes
|
|
X
|
|
|
|
|
|
A 5.4
|
Corrosion-resisting chromium & chromium-nickel steel covered welding electrodes
|
|
X
|
|
|
|
|
|
A 5.5
|
Low-alloy steel covered arc welding electrodes
|
|
X
|
|
|
|
|
|
A 5.6
|
Copper & copper alloy covered electrodes
|
|
|
|
X
|
|
|
|
A 5.7
|
Copper & copper alloy welding rods
|
X
|
|
X
|
|
|
PAW
|
|
A 5.8
|
Brazing filler metal
|
|
|
|
|
|
BR
|
|
A 5.9
|
Corrosion -resisting chromium & chromium- nickel steel bare & composite metal cored & standard arc welding electrodes & rods
|
|
|
X
|
X
|
X
|
PAW
|
|
A 5.10
|
Aluminum & aluminum alloy welding rods & bare electrodes
|
X
|
|
X
|
X
|
|
PAW
|
|
A 5.11
|
Nickel & nickel alloy covered welding electrodes
|
|
X
|
|
|
|
|
|
A 5.12
|
Tungsten arc welding electrodes
|
|
|
X
|
|
|
PAW
|
|
A 5.13
|
Surfacing welding rods & electrodes
|
X
|
|
X
|
|
|
CAW
|
|
A 5.14
|
Nickel & nickel alloy bare welding rods and electrodes
|
X
|
|
X
|
X
|
X
|
PAW
|
|
A 5.15
|
Welding rods & covered electrodes for welding cast iron
|
X
|
X
|
|
|
|
CAW
|
|
A 5.16
|
Titanium & titanium alloy bare welding rods & electrodes
|
|
|
X
|
X
|
|
PAW
|
|
A 5.17
|
Bare carbon steel electrodes & fluxes for submerged-arc welding
|
|
|
|
|
X
|
|
|
A 5.18
|
Carbon steel filler metals for gas shielded arc welding
|
|
|
X
|
X
|
|
PAW
|
|
A 5.19
|
Magnesium alloy welding rods & bare electrodes
|
X
|
|
X
|
X
|
|
PAW
|
|
A 5.20
|
Carbon steel electrodes for flux cored arc welding
|
|
|
|
|
|
FCAW
|
|
A 5.21
|
Composite surfacing welding rods & electrodes
|
X
|
X
|
X
|
|
|
|
|
A 5.22
|
Flux cored corrosion-resisting chromium & chromium-nickel steel electrodes
|
|
|
|
|
|
FCAW
|
|
A 5.23
|
Bare low-alloy steel electrodes and fluxes for submerged arc welding
|
X
|
|
|
|
|
|
|
A 5.24
|
Zirconium & zirconium alloy bare welding rods and electrodes
|
|
|
X
|
X
|
|
PAW
|
|
A 5.25
|
Consumables used for electro-slag welding of carbon & high strength low alloy steels
|
|
|
|
|
|
ES
|
|
A 5.26
|
Consumables used for electrogas welding of carbon and high strength low-alloy steels
|
|
|
|
X
|
|
FCAW
|
|
A 5.27
|
Copper and copper alloy gas welding rods
|
X
|
|
|
|
|
|
|
A 5.28
|
Low-alloy steel filler metals for gas shielded arc welding
|
|
|
X
|
X
|
|
PAW
|
|
Fluxes for welding
There is a number of different types of fluxes used in welding, brazing,
and soldering. These include fluxes for oxyfuel gas welding, fluxes for
brazing, fluxes for soldering, fluxes for oxygen cutting of certain
hard-to-cut metals, fluxes for electroslag welding, and fluxes for
submerged arc welding.
There are no specifications written for any of these fluxes. The
American Welding Society provides a specification for weld metal
deposited by different combinations of steel electrodes and fluxes
for submerged arc welding.
The major function of the submerged arc flux is to produce a slag
which will protect the molten metal from the atmosphere by providing
a mechanical barrier. When it is molten, this slag should provide
ionization to permit a stable arc. It should be fluid and of relatively
low density so that it will float and cover the top of the deposited
weld metal.
The melting temperature should be related to that of the molten weld
metal and it should have a different coefficient of expansion, providing
that it can easily be removed after cooling. The slag should provide
deoxidizers to help cleanse and purify the weld metal. It should also
help reduce phosphorous and sulphur that might be present in the base
metal. It should not introduce hydrogen into the weld. Finally, the
flux should be granular and convenient to handle, should not provide
noxious fumes, but should provide for a smooth weld surface.