CVN For E71T-11

Date 09-28-2005 01:46

E71T-11 was used on a job that I inspected. The WPS was for E71T-8. I called this to the foreman's attention and he said he would use it anyway. Now I want to educate the engineer (EOR) as to the improper application of E71T-11 as a structural filler metal. The Weld was a 2G flair. 3/8" A36 horizontal embed plate with 6" X 8" X 3/8" HSS A500 Gr B. on top. The flair bevel was filled to the surface in some cases and others were 5/16 depth of fill. This weld condition holds a modular building to the top of a CMU wall.

Where can I find documentation? Please tell me if I am barking up the wrong tree.

By swnorris (****)

Date 09-28-2005 11:30

I have not seen any CVN values indicated on wire certs for E71T-11. The wire manufacturers all basically say that this wire can be used on applications where CVN toughness is not of prime concern.

By waynekoe (**)

Date 09-28-2005 15:59

I think before trying to re educate the engineer, the first place you should go is to the project specs and see what was called out for filler metal requirements. If there are CVN requirements, then you have both legs to stand on. SWNORRIS is correct in that the 71-11 wires have no CVN values. The 71-8s' all have values starting at 20 ftlb @-20 and offer superb low hydrogen characteristics. Other than that, they both operate under approximately the same perameters, with the exception that the -11 cannot be used on materials thicker than 1/2". If the EOR doesn't have a problem with it, then you shouldn't either. Just have the welders fill out the bevels (or grind them out if it comes to that)and write it all up.

By swnorris (****)

Date 09-28-2005 17:32

waynekoe,

This posting by dschlotz is a a follow up to his previous post where he stated that there are no specs.:

http://www.aws.org/cgi-bin/mwf/topic_show.pl?id=7757#36331

The only thing I know is that since there are no specs., good documentation is critical. Even with no specs I would not use a wire that has no CVN properties on a structural project. In the other post dschlotz stated that the E71T-11 was being used because the welder liked it. As you said, they have the same parameters. Go figure.

By waynekoe (**)

Date 09-28-2005 18:11

Thanks for the clarification. I myself wouldn't use or recommend a 71T-11 wire for anything, but at the same time, I've had this same situation where the project specs had called for -8, the contractor used a -11 for a T1 truss splice (ran out of the good stuff) and the Engineer had no problem with them using a wire with no impact values for the splice connection.

By Shane Feder (****)

Date 09-28-2005 22:29

dschlotz,
What size wire were they welding with?
If I read the post correctly you are welding on 3/8" (9.5 mm) plate.
Lincolns website under Frequently Asked Questions states maximum plate thickness to be welded with E71T-11 wires .035"/ .045" is 5/1'6"
(8 mm).
I realise that CVN's , tensile strength, elongation etc are the most critical points but if you are looking at something basic to show the engineer then manufacturers recommendations are pretty black and white.
Regards,
Shane

By swnorris (****)

Date 09-28-2005 22:35

Shane Feder,

I saw that maximum 5/16 thickness too. Other manufacturers show up to 1/2" in thickness.

By Shane Feder (****)

Date 09-28-2005 23:14

swnorris,
My manufacturers handbook for an Australian made E71T-11 states "Applications include the general purpose fabrication or repair of mild and galvanised steel fixtures and structures including gates, fences, steel frames, galvanised tanks and ornamental iron work etc."
Doesn't sound like something you would use to hold a building up!!
Regards,
Shane

By swnorris (****)

Date 09-29-2005 10:05

I agree with you 200 percent!!