Good filler metal for working with AR235??

Date 01-08-2014 20:59 Edited 01-09-2014 02:26

Hello everyone! I hope all is well in the new year.
So I get to play with a bunch of .25" AR 235 plate jigsaw puzzle pieces that have to resemble a small box with a smaller slanted box on top of it. I'm not allowed to get pictures of it, sorry... This is the first one of a bunch to be done so we are still proving the part out before we cut a whole stack of bad parts. That also means I have to tack it lightly to check and see if all the jigsaw pieces fit. The issue I'm having with it is getting it to tack together and stay together long enough to adjust the fit and weld it. The fitting is tricky enough that I can only get small tacks while its clamped to makeshift fixtures and when I let the parts free they distort (of course...). In trying to shift them back to where they have to be they fall apart. I have tried 309, 70-s and 110-s with about the same results, pieces hitting the floor and me swearing at them.
We have worked with this stuff before on similar parts and have always had this issue with tacking and fitting, but never with welding. We have used both 70-s and 110-s to fill it all in with no issues.
These are all pulsed GTAW welds somewhere around 150 to 180 amps, .035 to 1/8th filler wire of above mentioned flavors depending on which part of the box is getting welded.
Anyone know of any other filler metals I can try? The tacks can be ground out and totally cleaned later after we know if they fit right or not so strange combinations are not out of the question (hastealloy x?)
Any tricks or magic that might convince the parts to stay together long enough to figure out if they are good or not? (Super glue and duct tape don't work..... don't ask how I know.... :roll:

)
I'll fill in any more details as needed, but I will add that these parts are nothing too super critical. They have to clamp together, slowly rotate and be abused by 2000 something degrees F and then sandblasted by black beauty or something just as savage. Repeatedly. Until they fall apart because the .25" plate is about .03 thick and all of the weld is gone. :lol:

Thank you all and have a good new year!
*edit AR 235 not 234...

By 46.00

Date 01-08-2014 21:59

pardon my ignorance, but what is AR 234 plate? I'm guessing abrasion resistant?

By PlasmaHead2 (***)

Date 01-09-2014 02:08

Yep, its a less alloyed version of ar500 I believe...
Chemical Composition (ladle analysis, wt. % max.)
C Mn P S Si
0.50 0.90 0.020 0.010 0.35
http://www.ssab.com/documents/north%20america%20products/ar235%20product%20data%20sheet%202012%2004%2001.pdf

By A_DAB_will_do (*)

Date 01-09-2014 15:59

If I'm reading your post correctly, and the Carbon content of that alloy really is 0.50 wt%, then I'll second Lawrence's suggestion. Something with a whole lot of nickel might tolerate all the carbon dissolving in the welds. You might also look at a 99% nickel TIG rod, intended for repairing cast iron. I'm not sure which would be less expensive or more readily available. You may or may not wind up grinding out those high nickel tacks, but you indicated that wouldn't be a problem.

If you're making small tacks, it seems possible to me that they are cracking due to the rapid quench with high carbon content. I know that warping is probably a concern, but a slow(er) ramp down on the TIG footpedal, to slow the cooling of the tackweld, might help reduce the chances of any cracking.

By aevald

Date 01-09-2014 00:17

Hello PlasmaHead2, if my memory serves me remotely correct I believe that some of the Nickle-alloyed 80 series gas-shielded flux-cored wires for steel might fit the bill for your tacking issues on that material. From my understandings of the metallurgical characteristics of those fillers they are pretty tolerant of stress and contraction issues and likely to accommodate your fitting challenges without coming apart. If this doesn't pan out for you I'll be interested to hear what others have to say and what you finally end up with. Good luck and best regards, Allan

By PlasmaHead2 (***)

Date 01-09-2014 02:24

Hello Aevald,
If I could find something like that in a TIG filler I'd give it a go but these parts are a little small for flux core. It would work for some of the joints on these parts but not all of them and having to switch processes around in the middle of welding would kill the time on the job. GMAW has worked in the past on plain steel with similar parts, but even then we had to GTAW some parts of it and it slowed the job down too much. And the usual gripes about spatter and "it doesn't look as good as the tig welds"...
I will look around at work and see if we have any 80 series filler wires stashed some where and see if it helps.

By aevald

Date 01-09-2014 05:28

Hello again PlasmaHead2, then possibly look into some tig filler for welding cast iron, you might find one that has a bit of nickel in it and will help with keeping things together for your fitting process. Is it possible to use a light preheat on these parts? say, something in the neighborhood of 250F or so, this might also help a bit.

Since it sounds as if you're experimenting here a bit I take it that there is not a hard and fast welding procedure in place that covers these parts. Or, are you simply fitting and then welding with another type of filler and thoroughly grinding and removing these tacks before the part is finish welded? You've sparked my curiosity and likely that of a lot of others. Good luck, Allan

By PlasmaHead2 (***)

Date 01-09-2014 23:24

Greetings once again everyone :grin:

We have victory! At least for now...
I ended up using a Ni-60 filler because that was the only filler we had in the right size range. We have a Ni-99 but it was 1/8th thick wire and way too awkward to tack with. Too much filler for too little area. I am going to see about getting an 80 series wire or something more compatible so I don't have to grind so much, but the Ni-60 is working for now.
I would try preheat but with the one I'm working on now we have a plastic part very close to what needs to be welded. A very expensive plastic part that happens to be the only one in existance at the moment... So I can imagine the screaming that would happen if I even hinted at bringing a torch near this thing...
You are correct in there is no written procedure for these parts, and more than likely never will be given the nature of what they do... The most important part of building these things is that they end up really close to where they have to be, with the welding being of almost secondary concern. The original versions from way back in these things history were created from parts plucked from the scrap bin and slapped together with what ever was laying around with very little care or regard... All we have really done is standardize them and make them as uniform as possible and much more professional looking. We also do a lot of development work so we see quite a few 1's and 2's of these things in various forms, and may not see the same one again ever. We developed the ones we make in house and I get to work directly with the engineer who came up with most of these things on top of getting plenty of feedback from the customers... so if something was going wrong with the welding I would have herd about it. Most of the time the welding issues stem from not welding parts full and trying to use stitch welds to help prevent distortion.
I will keep pestering to see if I can get some pictures of these things to show you guys...
Thank you all for the ideas and assistance!

By aevald

Date 01-10-2014 05:59

well, glad to hear that you are having some success and yes, if they let you it would be really neat to see what this thing looks like. Best regards, Allan

By PlasmaHead2 (***)

Date 01-11-2014 18:24

Well, I pestered but to no avail... No one wants to risk ticking off the customer. So no direct pictures, but I might be able to get some close up shots of the welds. Might. Turns out a couple of the features on the thing are kinda sight critical...
I did however search youtube and came up with some videos that ALMOST resemble what I'm working on....
http://www.youtube.com/watch?v=fqaEAMnf_Uc&list=PLE27DF4CC393114F0 : This is a bigger part of a very similar critter to what I'm working on.... Not the blades but the bits on the top and bottom of it.
http://www.youtube.com/watch?v=ah9kLdUFDQY This video has some annoying music, but at about 2:50 they show a part that's a lot closer to what I'm working on, Yet still not even close to the right shape (or company) so that no one gets in trouble... Again, not the blade but the things clamped to the bottom of it.

That's about the best I can do for a description at the moment...

By aevald

Date 01-11-2014 18:50

Thanks PlasmaHead2, when I get a moment or more to myself I'll give those a look. Best regards, Allan

By Lawrence (*****)

Date 01-09-2014 12:42

My fall back choice for *unqualified* dissimiliar metals tacking is Hastelloy W (AMS 5786)

It is a GTAW filler designed for exactly this purpose...

I have used myself and have watched others do some pretty amazing stuff with it.

http://www.haynesintl.com/pdf/h3017.pdf

.

By PlasmaHead2 (***)

Date 01-09-2014 23:26

I've been asking for a pound or so of that wire for a bit now... We get lots of fun unqualified stuff to do along those lines. Lots of favors for the bosses friends and whatever silly ideas they come up with.... :eek:

By Lawrence (*****)

Date 01-10-2014 12:59

When I was a lad working in a Jet shop, we would often make one off, or custom jigs and fixtures out of old scrap engine parts which might be anything from single crystal blades to precipitation hardenable, to Rene 41... Just anything the right shape that was in the bin.

The Has-W really never failed....

Hastelloy W was also selected quite often for Engineering Variance (EVA) work on wing, where an engine needed a bracket or lug repaired by welding but the base metal typically required an annealing prior to welding, which was impossible. Inco 718 being one example.

But in a pinch I have used 347 (AMS 5680) with good results also.

By PlasmaHead2 (***)

Date 01-11-2014 17:30

In my searching of the shop I managed to find a bunch of what I think is 1/8th" AMS 5798(its old and the numbers are hard to read)... which from what the internets has told me is hastelloy X. Any chance that the hast x will play like the hast w?