ASTM A572 welded with E71T-1m FCAW

Date 12-03-2009 16:23

Mikeqc1
AWS: A5.20-95 which I don't have but,
Yes sir we use it. daily for both A572 and A992 Beams.
We use a 75/25 Argon/CO2 mix.
When we were welding from AWS D1.5 Bridge Code I had to Qualify the Procedure but with AWS D1.1 it can be prequalified with the right variables inputed.
We are running Kobelco wire these days and it is ok we do run the mix gas as it gives more versatility in weld position http://www.kobelcowelding.com/prod_frontp1.htm
Marshall

By swnorris (****)

Date 12-03-2009 17:58

Mikeqc1,

E71T-1M. It's definitely A5.20 as Marshall said. The M indicates that it's for mixed gases. E71T-XM is a prequalified filler metal (Table 3.1) for A36 and A572 Grade 50 base metals, as long as the 572 is Grade 42, 50, or 55. I assume that you have Grade 50, which is the most common in structural applications. If it were Grade 60 or 65, that would complicate things a little.

By Mikeqc1 (****)

Date 12-03-2009 19:03

Thanks guys.
Always a big help.
MDK

By eekpod

Date 12-04-2009 17:43 Edited 12-04-2009 17:46

A little late but we use it also, only Lincoln E71T-1. Mixed gas w/ A36, A572, A992, A500 w/ out any problems.
I re- read your original post. If its a W shape, you won't find A36 in W shapes. they changed the spec. to A992. then go to D1.1 and look up filler wire vs base material and you'll find A992 listed there along w/ A36 in different thicknesses.
But anyway they changed it about 8 yrs ago I think, go to AISC FAQ and its posted on there.
Chris

By HgTX

Date 12-04-2009 18:44

Stupid question, but did you verify that the A572 instead of A36 is okay? (Or was that covered in another thread?) (Or am I misunderstanding the situation?)

Hg

By eekpod

Date 12-07-2009 11:12

it's ok per D1.1 if thats what your asking.

By HgTX

Date 12-07-2009 15:56

No, I mean ok with the designer. ASTM A 36 has an upper limit on tensile strength that some designs count on (like if you're relying on one component to fail before another). It's usually not an issue, but it could be.

Hg

By eekpod

Date 12-08-2009 11:40

MikeQC sisnce it's not my original thread I can't answer that.
My bill of material states the different grades of material, and we don't swap grades of material back and forth w/out approval.

I was coming from a bigger code perspective. I thought the original post was asking if its ok to use a certain wire w/ a certain base material, and my response was geared from the code will tell him what combinations will be ok.
Chris

By Mikeqc1 (****)

Date 12-08-2009 22:40

i rejected the material wrote it up as po calls for xxxxxx (no longer available) and we recieved yyyyy. the engineers sent back documentation stating they are ok with what was recieved.
so im ok on that end.
I was just concerned with the wire.
for ASTM A572 grades 42,50,55 E71T-1m is ok but if i was given ASTM A572 grades 60,65 that wire would not be acceptable.
I do have that correct?
Thanks
MDK

By eekpod

Date 12-09-2009 11:34

MikeQC1, I went and pulled out D1.1.
Table 3.1 Pre-qual Base Metal FIller Metal Combinations for Matching Strength pg 67
A572- gr 60,and 65 is group III. That would require FCAW per A5.29 E8XTX-X filler metal.
This is different than if it were grade 50 then it would be a group II and E7XT-X.
Hope this helps.
Our purchasing dept knows not to change out the grade w/ out checking first, then when I tell them no, they don't buy it. This way I won't have what you had. SOmetimes they just hear the A572 from the supplier, not the grade, and then when I get the cert. and its wrong a big issue comes up.