Page 7 - SD 2205

 Interpass temperature must be limited to 150°C (302°F), or better 120°C ( 248°F).

 Post weld heat treatment is not necessary, except if, in particular cases, welding
without filler metal for instance, a lower ferrite content is required. Heat
treatment will be realised at a sufficient temperature to avoid phase
transformation.

 Usual precautions including cleaning and degreasing of weld area, protection
against weld spatters must be taken to ensure corrosion resistance of the
finished product.

 Careful final mechanical or/and chemical cleaning of the weld is highly
recommended.

 Plasma + TIG welding
Typically used for thicknesses of 5 to 12 mm
If no filler metal is used for the plasma pass, Ar + (2-3)% N 2 will be used as
shielding gas.
Ferrite content will be between 30 and 60 %. Complementary TIG welding will
also be realised with a duplex or super-duplex wire. The ferrite content will also
be kept between 30 and 60 %.
Nitrogen additions (2-3%) in the protective gas improve the corrosion
behaviour and stabilize the microstructure. Technical is available for special
cases. Contamination of the shielding gas by hydrogen must be avoided.

 Manual arc welding
A standard duplex or super-duplex electrode will be used. The ferrite content is
between 20 and 40%. Avoid hydrogen pick up (moisture, hydrogen containing
gases...) which can result in cold cracking.
For further information, please contact us (choice of the electrode depending
on the application).

 Submerged arc welding
This process can be used for single pass or multipass welds for high
thicknesses (10 mm) or to complete a plasma pass. The filler metal is a
duplex wire basic fluxes should be preferred.
Ferrite content will be controlled between 20 and 40 % in order to avoid cold
cracking risks ; Use only well dryed fluxes to avoid hydrogen pick up.

DESIGN SD 2205 is particularly cost effective when its high mechanical properties of the
alloy are taken into account to design vessels.

Allowable design stress values : ASME Boiler and Pressure vessel code
Section VIII - Division 1, Stress, MPa - KSI

-30/40°C
Grade (-20/100°F) 205°C (400°F) 260°C (500°F)
MPa KSI MPa KSI MPa KSI
316L 108 15.7 74 10.8 68.9 10
904L 123 17.8 95 13.8 87 12.7
SD 2205 155 22.5 144 20.9 141 20.4

These higher design stress values allow the fabricator to reduce the weight of the
equipments which, combined with the high corrosion resistance properties, provide
additional cost savings.