A "16" electrode has a titania or rutile based coating and can be used
with both DC and AC polarity. Electrode sizes of 5/32 in. (4.0 mm)
and smaller are often used for all welding positions.
A "17" electrode has a silica-titania type coating and is a
modification of a 16 coating, in that some of the titania is replaced
with silica. They also can be used with both DC and AC polarity.
Additional silicon in the coating acts as a wetting agent, having the
effect of increasing puddle fluidity. This is particularly helpful
with stainless steels, as they tend to have more of a sluggish weld
bead than carbon steel.
L-17 type electrodes produce a flatter bead profile than the other two
types and are often used for flat and horizontal position welding.
However, electrode sizes of 4.0 mm and smaller can be used for all
position welding. Note that with a vertical up progression, the
slower freezing slag will require more of a weave technique than with
a 16 type electrode.
There is no need for requalification since F-Number and A-Number are the same.
Ramin Kondori
QA/QC Manager
IRAN-LNG project
(IWE AT 0070)
On 3/1/12, Peyman Hafezi <peymanhafezi@gmail.com> wrote:
> Dear friends
> We have a WPS for welding 321-SS base metal with ER 308h+E 308h-16 which
> is approved by PQR but the matter is non-availability of E308H-16 and we
> would like to use E308H-17 instead.
> There is no mechanical and chemical difference between these two according
> to ASME Sec II Part C, the only difference is in cover composition that
> makes -17 better for fillet welds in comparison with -16. But the question
> remains because our joint is groove and not fillet. What's your opinion?
> Could -17 be used for groove welding instead of -16 ( without need of a new
> WPS and PQR) ?
>
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The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
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