Together we weld stainless
80 YEARS OF EXPERIENCE IN THE DESIGN OF HIGH QUALITY
STAINLESS STEEL WELDING CONSUMABLES
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Together we weld stainless
The history of stainless steel
Stainless steel has been around almost as long as the coated welding
electrode. The latter first appearing in 1904, following the pioneering
work of Oscar Kjellberg, the founder of ESAB. Stainless steel was
developed independently in 1913, by researchers in Great Britain and
Germany, with the first true stainless melted on the 13th August 1913
in Sheffield. The first duplex stainless steels were produced in Sweden
around 1930 for applications within the paper industry. However,
commercial production of precipitation hardened stainless grades did
not take place until after the Second World War when new grades of
stainless steel with improved weight-to-strength ratios were needed
for jet aircraft.
Basic facts about stainless steel
“Stainless” was a term coined early in the development of steels used
by the cutlery industry. It became adopted as a generic name and now
covers a wide range of steel types and grades used in corrosion and
oxidation resistant applications. Stainless steels owe their corrosion
resistance to the presence of a “passive”, chromium-rich, oxide film
that forms on the surface. Although extremely thin and invisible to the
eye, this protective film adheres firmly, and is chemically stable under
conditions, which provide sufficient oxygen to the surface. Furthermore,
the protective oxide film is self healing providing there is sufficient
oxygen available.
Main types of stainless steel
Ferritic stainless steels
Ferritic stainless steels have properties similar to mild steels but with
better corrosion resistance, due to the addition of typically 11-17%
chromium. They are comparatively inexpensive due to their low Ni-content
and have good resistance to chloride stress corrosion cracking.
Consumables for the welding of ferritic stainless steels can be ferritic
with a composition matching the parent metal or austenitic. Ferritic
stainless steels are resistant to corrosion in sulphur containing
atmospheres. The use of austenitic consumables is not recommended
for this type of application.
Stainless steel type
Some commonly used variants are those which contain Mo to provide
improved pitting corrosion resistance, those with Nb or Ti to stabilise
against Cr-carbide precipitation and higher strength N-alloyed grades.
Corrosion resistance is very good to excellent, depending on alloying
content and environment.
Austenitic stainless steels are welded with consumables with a similar
or over-alloyed chemical composition. Over-alloying is required for
the more highly alloyed grades to optimise corrosion resistance by
compensating for segregation effects in the weld metal. Highly alloyed
nickel-based consumables are generally used for superaustenitic steels.
Duplex (austenitic-ferritic)
Duplex stainless steels have a mixed structure with approximately
equal proportions of ferrite and austenite, hence the term “duplex”.
They are alloyed with a combination of nickel and nitrogen to
produce a partially austenitic lattice structure and improve mechanical
properties and corrosion resistance. There is a wide range of duplex
grades all offering an attractive combination of high strength and
good corrosion resistance. Having grown to a large family, the duplex
stainless steels now range from the lean grades, that are cost efficient
and compete with the standard austenitic grades, to the highly alloyed
superduplex grades for more demanding applications. Generally,
duplex stainless steels have good weldability and can be welded using
a wide range of welding processes.
Chemical composition (%)
Standard grades
Special grades
Ferritic
<0.08 C*
10.5-19 Cr
0-2.5 Ni
0-2.5 Mo
+ Ti, Nb
- increased Cr, Mo,
- extra low C and N (ELI)
Austenitic
<0.08 C*
(typically <0.03 C)
16-19 Cr
6-16 Ni
0-5 Mo
-
<0.03 C*
18-30 Cr
1.5-8 Ni
1-5 Mn
0-4 Mo
0.1-0.3 N
- increased Cr, Mo, N
- sometimes Cu, W
Duplex
(austenitic-ferritic)
Austenitic stainless steel
The most widely used group of stainless steels found in numerous
applications, austenitic stainless steels have a nickel content of at least
6% to stabilise the structure and provide ductility, a large range of
service temperatures, non-magnetic properties and good weldability.
A large number of steel grades have been developed starting from the
classical base composition 18%Cr/8%Ni.
increased Cr,Mo, Ni,
stabilisation with Nb, Ti,
sometimes Cu, N
improveded machinability with S
Applications
Household machines, automotive parts, chemical industry.
Equipment, vessels and pipelines within chemical,
food, power, oil, gas, pulp and paper industries.
Oil, gas, chemical industry, pulp and paper industries, heat
exchangers, chemical tankers.
* typically higher C-content in creep and heat resistant steels
ESAB have a new range of lean duplex welding consumables
see back cover for details.
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The ESAB stainless steel welding
consumables range
Covered electrodes for manual metal arc welding
Over recent decades many fabrications traditionally welded with
covered electrodes have been transferred to more productive methods
such as submerged arc and flux cored arc welding. However for
applications where flexibility is essential the covered or manual metal
arc (MMA) welding process is still the best solution. ESAB’s range
of stainless steel MMA electrodes are categorised according to their
coating composition into rutile, basic and high deposition types.
VacPac™ Packaging
All ESAB stainless steel electrodes are packed in vacuum packaging.
VacPac™ is available in various sizes, ranging from 0.7 to 2.0kg.
Solid wires for MIG welding
The most commonly used stainless grades are produced with a matt
wire surface, due to a special manufacturing process. This technique
produce wires that give a better welding quality, greater arc stability
and higher production output. The matt surface is finished with a
special feed-aid that does not accumulate within the feeding system
or welding gun.
The majority of wires are available in ESAB bulk wire system,
Marathon Pac™. This package promotes lean manufacturing through
reduced downtime, process stability and efficient consumables
handling. It saves on handling time and spool disposal costs.
Marathon Pac has built in lifting straps and a range of accessories that
simplify on-site handling from goods-in to workstation. Once empty,
the octagonal drum packs flat to save space and ease disposal.
The Pac is also 100% recyclable. Marathon Pac are available in
100kg Mini Marathon Pac, 250kg Marathon Pac and 475kg Jumbo
Marathon Pac for high volume users.
Rods for TIG welding
The TIG welding process is particularly suitable for the welding of
lighter materials, metals as thin as 0.3mm can be welded successfully.
For heavier sections, 5 to 6mm the TIG process is often used for root
runs prior to filling using the MIG or MMA process.
Tubular cored wires for MIG/MAG welding
The ESAB range of tubular cored wires offer the fabricator a genuine
opportunity for increased productivity over solid wire and manual arc
electrodes with excellent quality. The benefits can be summarised as:
• Up to 30% increase in weld metal deposition rate over solid wire and
four times that of manual metal arc resulting in faster weld speeds
with less distortion.
• Moisture regain is minimal ensuring that start porosity is eliminated.
• Rutile types are designed for use with Ar/CO2 or CO2 shielding
gas. The latter serves to reduce gas costs and radiated heat is also
significantly lower giving greater operator comfort.
• Welder appeal, easy to use without the use of pulsed welding
equipment.
• ESAB’s individual batch testing of weld metal composition means
that the most stringent of quality standards are always met.
Fluxes for submerged arc welding and cladding
Submerged arc welding (SAW) is a method in which the heat required
to fuse the metal is generated by an arc formed by an electric current
passing between the electrode and the work piece. The arc itself
is submerged under a granulated powder or submerged arc flux
protecting the weld pool from the atmosphere.
Shield-Bright wire series
The all positional Shield-Bright wires have a fast freezing slag to
support the weld metal. This enables deposition rates in positional
welding that cannot be equalled by stick electrodes or solid wires.
Typical positional welding defects, such as lack of fusion and slag
inclusions are avoided due to the spray arc operation.
Shield-Bright X-tra wire series
The Shield-Bright X-tra range is optimised for downhand and horizontal
vertical fillet welding, having a slow freezing fluid slag to allow high
travel speeds. Shield-Bright X-tra can be used for vertical up welding,
but their more fluid slag, is optimised for downhand operation. SheildBright wires are the preffered choice for this position.
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ESAB OK Tigrod’s are packaged in round rigid fibre tubes with
hexagonal end caps to prevent rolling. The tubes are PE coated
which together with the re-usable end caps act as an effective barrier
against moisture.
Flux
ESAB submerged arc fluxes are delivered in 25kg paper bags with
some types in 20kg bags. Each bag has a polythene inlay in order to
reduce moisture pick up from the surrounding atmosphere or in
1000kg aluminium Big Bag. For the more robust environments ESAB
can also supply in steel buckets containing 25 to 30kg flux.
Wires
Stainless and Ni based submerged arc welding wires are usually
delivered on 25kg wire baskets. Wires 1.6 and 2.0mm in diameter
can also be supplied in 475kg octagonal cardboard Marathon Pacs.
In the Marathon Pacs the wire is pre twisted for straight delivery.
Cladding
Strip (or cladding) electrodes are supplied in cold rolled condition
in 25, 50, 100 and 200kg coils all with inner diameters of 300mm.
The strip thickness is 0.5mm and can be supplied in widths of 30,
60 and 90mm.
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ESAB welding consumables for
lean duplex stainless steel
The combination of high strength and comparable corrosion
resistance has made lean duplex stainless steels a cost
competitive option in numerous applications where traditionally
AISI 304 and AISI 316L materials are used. Typical applications
are desalination plants, pipes, storage tanks, floodgates and
footbridges. In certain applications such as black liquor where
Mo has been found to have a negative effect on the corrosion
resistance, lean duplex grades have replaced duplex grades.
Although most lean duplex stainless steel grades can be welded
successfully with standard duplex 2209 type consumables, lean
duplex consumables offer a more cost efficient solution while
matching mechanical properties and corrosion resistance are
guaranteed. To avoid excessive amounts of ferrite in the weld metal,
they are higher alloyed with austenite promoting elements than the
corresponding steel grades. The ESAB range of lean duplex
consumables consists of:
•
•
•
•
•
MMA/SMAW: OK 67.56
MIG/GMAW: OK Autrod 2307
FCAW: Shield-Bright 2307
TIG/ GTAW: OK Tigrod 2307
SAW: OK Autrod 2307/OK Flux 10.93
AISI/
UNS No.
EN No.
Grade
OK Autrod 2307
Shield-Bright
2307
OK Tigrod 2307
OK Autrod 2307/
OK Flux 10.93
ESAB lean duplex consumables
OK 67.56
Lean duplex stainless steel grades
The table reviews lean duplex stainless steel grades that can
be successfully welded, including some important footnotes
on exceptions.
S32001
1.4482
19D
x*
x
x
x
x
S82011
2102
x*
x
x
x
x
S32101
1.4162
LDX 2101®
x*
x
x
x
x
S32202
1.4062
2202
x*
x
x
x
x
S32304
1.4362
2304
x*
x
x
x
x
2003
1
1
1
1
1
2
2
2
2
2
S32003
1.4655
* Apply stringer beads or moderate weaving. Excess weaving causes poor slag detachability. AC/DC+ polarity.
X: Well suited for the job.
1: Lean grade can be used if slightly undermatching corrosion resistance is acceptable.
2: Suitable except when Cu-alloying is required.
ESAB AB
Box 8004. SE-402 77 Göteborg, Sweden.
Phone: +46 31 50 90 00. Fax: +46 31 50 93 90
Email: info@esab.se
www.esab.com
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