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Up Topic Welding Industry / General Welding Discussion / Filler rod size for 1/32 to 3/32 stainless
- - By andrewsullivan9 (*) Date 09-26-2010 19:22
On a job we are doing at the minute we are doing a lot of stainless thin guage plate material, im mainly used to welding large bore stainless pipe backpurged with argon, i was just wanting to know what filler rod size you guys prefer to use on this sort of material when its not possible to weld without filler. Im managing to get my fillet welds the correct colour and size although im having problems getting colour on my butt welds, at the minute im using a 3/32 tungsten and a 90 degree torch angle with a large stickout any advice?
Parent - - By Tommyjoking (****) Date 09-26-2010 20:02
you are not clear on the size, grade, filler, gas, machine used or what have you of your process,  if you want good answers you need to provide details of material grade, thickness, joint configuration, filler grade, machine used, process used (including gas mixture).......what I gather your welding is .30 approx  SS material.  ASSUMING GTAW

So given the info/GUess I got I will say this: .040 tungsten (thoriated is fine, #6 cup, 15 cfh for fillet/20cfh for butt (#15 gas lens would be way better), 100%argon......use a thick tight fitting (1/8") copper plate for backup on either joint or use a steel/copper fixture with a prodigious gas backup.  For this I would be using a .25-.20 filler for first choice, .030 filler second choice.

Your tungsten is LARGE for the job unless you are really sharpening it to a needle, bout a 3/8 length of grinding.  A negative torch angle is not a bad idea, in other words push your gas back over the hot puddle....thats where the grey is coming from...inadequate gas coverage because the puddle is long to cool...SS is notorious for this...a pretty good size lens cup will solve this issue.  Make sure your stickout allows for your tungsten to end up shiney and maybe blued......if your tungsten is turning dark at all you have way too much stickout.

Give the above info and you will get specific parameters to make it go well.
Parent - - By andrewsullivan9 (*) Date 09-26-2010 20:51
Tommyjoking were using approxiamately 0.04 316 stainless steel mostly up to 0.1, pureshield argon 99.9 percent argon size 6 cup with a butt tight connection wih argon backing,around 30 ish amps for the thin stuff up to about 75 amps walk the cup for the thicker grade, yes i appreciate the tungsten is too big at the minute although i intend to change to the smaller size as soon as possible gas flow around the 13 cfh mark
Parent - - By Tommyjoking (****) Date 09-27-2010 18:18
You might want to try a gas trailer if you can rig one up.....I use to use them lots where there is room to use them.  They help quite a bit.  I have built little gas dams around joints as well and just let argon trickle in there and make sure there was no fans on nearby.  Your amperage and everything sound fine to me.
Parent - By welder5354 (**) Date 10-03-2010 02:24 Edited 10-03-2010 02:29
If your having problems with discoloration and what to get all that blue off; Then you have two choices.
1: Use a stainless steel brush; After you stop welding, let it cool for about 3-5 minutes.
Then brush lightly, but keep brushing lightly until all the blue is gone.  I just welding a bunch of
nipples into a 3/4 in stainless steel tubing.  After it was all finished, then was not a peck of discoloration to be seen.
2: If you don't have time to wire brush your material during welding, then do it this way.  After it cools down, get some pickle
paste, put it on with a paint brush, leave it for about 2 hours and then water wash it off.  It will be as shiny as the base material.
Even with a 3/4 inch gas lens, you will still get discoloration.  Don't wire brush when the weld  it is red hot or when it has cool down completly.
It is very hard to get off when cool down completly.
Parent - - By Lawrence (*****) Date 10-03-2010 15:26
I hear this question pretty regularly.

I guess it's time to answer the question with a question.

What code or final inspection criteria are you attempting to comply with that has regulations about the color of post weld oxide on the weld face?

There is lot's of talk about "correct" color and there are for sure many techniques to reduce oxides on the weld face of stainless welds.

But there are actually very few applications where stainless oxide color on a weld face, has any affect at all on mechaicals, or finished componant performace if it is simply brushed off or passivated.  Nor are there many codes that have inspection criteria that evaluate oxide colors on stainless.
Parent - - By Superflux (****) Date 10-03-2010 15:59
When testing welders on S/S GTAW all passes, I like to see the final weld cap in it's as welded colors. Much can be interpreted of their expertise from those colors. I dont throw a hissy fit if they do "accidently" brush it off. It simply gives me a visual reference to the consistency of their technique, and often the field supervisors ask me to recommend them to certain assignments.
The old school "industry standard" was to not brush off the color. Welders took great pride in leaving the cap that gold or pink color. Can't say as I've ever seen any contract docs that required any particular color. It also was once common practice to ring file the toes of pipe weld caps to even out the width and improve overall appearance. Most places do not want you to waste the time and too many welders are trying to blend out unacceptable undercut. Oops! rambling
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Parent - - By Lawrence (*****) Date 10-03-2010 19:56
Not to be too critical here Superflux ..

but really... Who cares what an inspector "likes" to see?

... Unless all the inspector likes to see code compliance.

If it's a training session... Sure,, I don't let my students brush their stainless welds before visual...  But if it's a code job.. Thats just not what the inspector is looking for in most cases.

But in 99% of austinetic stainless welds..  a pretty gold color, or red, or blue or even possibly grey may not make a spec of difference if the weld is brushed or passivated.
Parent - - By Superflux (****) Date 10-04-2010 03:17
Lawrence,
As I stated, often times I am asked who is the better welder by the field supervisors. Weld tests for employment may not be a training session, but they are an open book to a welders' skill level and or fudging/cheating abilities. I can usually tell by the oxidation colors whether that cap is welded with filler metal or autogenous. Grey can be an indication of excessive heat input beyond procedural allowances. I don't reject ugly. Personally, I'd just soon let the "Evil eyed Unemployment Truck" or one armed Johnny (the bend jig) sort them out.
I've had instances where test welds were ugly yet passed visual criteria only to have the superintendent come by and refuse to allow the test to be bent or RT'd and send the poor soul packing. When that happens, it's their call and they can do the dirty work of passing the message. Sure wish it were a perfect world out here in the trenches...
And as always, I welcome criticism from any here in the forum. Keeps my thinking in, and outside the box.
Parent - - By andrewsullivan9 (*) Date 10-04-2010 03:34
Yea really just for the visual test i have no problem achieving gold and silver root runs when welding stainless steel pipe which i normally do although im finding it difficult getting consistent gold colour on thin sheet mainly because of the setup i have been using the larger tungsten etc for my pipe my smaller size tungstens are in the post and i now have an argon backing which is helping on the very thin stuff i will try to get some pictures up when i get my new setup working
Parent - By Superflux (****) Date 10-04-2010 04:11
andrewsullivan9,
Walking the cup is probably too slow for this thin of material if you are tryin to maintain any color that we are used to seeing on sch 40 pipe. "Color" is all about keeping it cool and complete gas coverage until the air hits it.
Parent - - By 46.00 (****) Date 10-30-2010 22:26
Hi!

I realise this is a pretty old post, but have to agree with superflux on this one! Color of finished weld can tell an inspector or tester so much about how it was welded and also point out problem areas with individual welders!
I always like to see a S/S butt weld as welded, so to speak! And No, it's not code requirement, but can be client requirement!
Parent - - By Blaster (***) Date 10-30-2010 22:41
I believe Boeing uses a set of color comparison pictures as part of the their go / no-go criteria.
Parent - - By Lawrence (*****) Date 10-31-2010 13:58
Not on stainless they don't.
Parent - By Blaster (***) Date 10-31-2010 19:52
My mistake, I believe you are right, not on stainless.
Up Topic Welding Industry / General Welding Discussion / Filler rod size for 1/32 to 3/32 stainless

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