17 / 40
June 2017
AFRICAN FUSION
15
The Phoenix welding system provides
the GMAW process with up to 550 A in
spray or pulsed mode, while the Tig-
speed unit provides thewire preheating
with a hot wire current of up to 180 A.
The GMAW hot wire configuration
described above is being
used for the cladding of al-
loy 625 on valves, fittings
and accessories for the
oil and gas industry. The
individual components
have diameters of up to
2.0 m and weights of sev-
eral tons. The area of the
surfaces, which are being
clad to improvement their
corrosion resistance, are
also large.
Productivity andqual-
ity of the clad layers must
be optimised to give the
best possible outcomes for the com-
pany. Wire feed speeds of 10 to 12 m/
minwith 1.2mmwire diameters for both
wire feeding systems result indeposition
rates of over 13 kg/h. At the same time
the dilution is comparable with previ-
ously used TIGhot wirewelding process.
Figure 8 shows the process being used.
Conclusions
The application of the GMAW welding
with hot wire support offers a realistic
alternative to traditional cladding pro-
cesses. It combines high deposition rate
Figure 8: The GMAW hot wire welding system in use.
andhigher productivitywith lowdilution
and lowpercentages of Fe in the surface
layer, which results in better corrosion
resistance properties for the clad layers.
The required equipment is available
as standard in today’s welding technol-
ogymarket. All components have digital
and analogue interfaces, giving the user
easy tools to configure, setup and use
the system with minimal investments
in time and money.
Copyright
©
2016 International Institute of Welding:
Originally published in the proceedings of the
IIW International Conference of 2016, Melbourne,
Australia.
References
1 TWI global. (n.d.). Retrieved 04 21,
2016. fromhttp://www.twi- global.com/
capabilities/materials-and-corrosion-
management/surface-engineering-and-
advanced- coatings/cladding/.
2
www.specialmetals.com. INCONEL data
sheet. Special Metals Corporation. 2013
(Aug 13).
3 J Slania; R Krawczyk; S. Wojcik: “Quality
requirements put on the Inconel 625
austenite layer used on the sheet pile
walls of the boiler‘s evaporator to utilize
waste thermally”; Archivesofmetallurgy
and materials – Vol. 60, 201,5 Issue 2.
DOI: 10.1515/amm-2015-0192.
4 J Norrish: “Advancedwelding processes
– technologies and process control;
Woodhead publishing in materials.
2006.
5 BerndRutzinger: “Influence of theweld-
ing process to the dilution rate of weld
overlays on unalloyed steel using the
weld consumable ERNiCrMo-3 (Alloy
625)”; Biuletyn instytutu spawalnictwa
Nr.5/2015.
Figure 6:
The Phoenix 551
Progress Puls GMAW welding system.
Figure 7:
The Tigspeed
drive 45 hot wire system with its integrated
power source.
GMAW cladding using hot wire