It would be easier if you had been a little more specific, but I will assume you are referring to EXXT-11 self shielded flux cored wire. This is an all position electrode that operates on DC electrode negative, has a smooth spray type arc and is good for single or multiple pass welding. One procedure example I have: E71T-11, 3/32" electrode, 130 ipm, 25 - 26 volts for 5/16" + steel. I would not hesitate to write a WPS and qualify it with this wire. I hope this helps.
Respectfully,
Mike Sherman
Shermans Welding
I apologize for my last post, I just realized that you did specify E70T-11 in your heading. It changes the usability of the electrode. 0 instead of a 1 tells you that it is not an all position electrode. EX0T = horizontal and flat position, EX1T = all position.
Mike Sherman
Shermans Welding
I am not aware of any code restriction per AWS D1.1 however I believe their are some issues with that classification that sometimes restrict its use. I worked at a manufacturer that had used it succesfully for years. Here are some possible reasons for its restriction.
1) There is a deposited weld metal limit. I think this was due to a buildup of elements in weld metal during welding. Check with the manufacturer and see what they recommend.
2) I have not seen the weld deposited with this filler metal repaired or welded over with FCAW, GMAW, and GTAW. I didn't beleive it was a problem at first, when I tried it myself, I believed.
Many customer prepared specifications prohibit the use of self shielded FCAW with no regard for the electrode classification. Again, I'm not aware of any restrictions for structural use by any AWS Code.
Gerald Austin
http://www.weldinginspectionsvcs.com
The restriction for the EXXT-11 stems from building code recommendations and requirements from FEMA and AISC which prohibits the use of any electrode without impact (Charpy V-Notch) requirements to be used in seismic zones 3 or 4. Examples of other electrodes (regardless of the process) not permitted for use in these areas include: E7024, E7XT-7, ER70S-5
It should be noted what requirements are deemed acceptable for use as far as impact properties (20 ft-lbf @ 20 degrees below zero or 20 ft-lbf @ 0 degrees, etc.) has yet to be decided by the powers that be.
i ran into this question from a customer who i supply his weld supplies
an engineer told him he could not weld structual steel over half inch
with this wire. i checked aws book and it says not to be used over 3/4
but check with the different mfg.
so hobart and lincoln both cover thier behinds by putting in thier spec sheet for this wire not to exceed 1/2''
so i got with mfg. hobart and got them fabshiel 7018 wire no thickness limit, self shielding wire.
this customer is in the fab of large buildings parking decks etc.
they are happy now as far as i know the person who shut the job down is to.
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