Stainless Rod for Certification

By pipewelder_1999 (****)

Date 08-21-2001 13:54

I have used Avesta, Sandvic SS electrodes and actually thought I was a SS stick welder.

I then went back to McKay and realized it was only a dream.

Good Day

Gerald Austin

By armywelder Date 08-21-2001 15:00

Thanks for the help. I look into those brand names. Now the situation has changed. We're now certifying a welder 6G using 2" OD pipe 304 SS to 304SS.

Pretty sure the electrode we'll be using is E308L-16. Brand name is Harris Welco. Anyone used that one?

Any ideas about diameter of stick? Thinking about 1/8" for root and possibly 3/32" for cover pass.

By pipewelder_1999 (****)

Date 08-22-2001 02:26

Thats mighty big for root.

I'm more of a 5/64" and 3/32" person but that could be more related to MY skill and not the rods.

Good luck

Gerald Austin

By dasimonds (**)

Date 08-23-2001 06:04

Is this an open root test? With E308L-16? What schedule? I can't say I've ever heard of anyone rooting stainless pipe with stick rod.

By armywelder Date 08-23-2001 11:38

Yes, this is an open root test. I figure a 1/16" of an inch root opening. 2" SCH. 40 304 SS on the pipe. I know it seems a little odd not to TIG the root. But, hey, we're kinda outdated here and doing the best we can with what we have. Unfortunately, stick will have to do.

By dasimonds (**)

Date 08-24-2001 00:21

I apologize for my incredulity at welding open root Stainless pipe with SMAW, but I couldn't imagine anyone doing it. I've been a welder for more than 20 years, and that's way outside my experience. But I see from the other posts that it has been successfully done before. That must be one tough test! Does the bevel on the pipe have a land?

By - Date 08-24-2001 01:28

Hi Dasimonds,

I can't speak for armywelder because there are many different ideas as to what makes a weldable, open root joint with the alloys. We used a tight 3/32" root opening with 3/32" lands.

Some welders run a keyhole, some bury the arc. It's whatever works for each welder. The best technique I found to qualify and consistently meet the quality standards in production work was to run extermely fast (compared to welding CS roots) with a tight arc, maintain a small but uniform keyhole, and "tick" each side of the joint with the electrode. My old instructor, who has gone to the Great Welding Shop Beyond, refered to my technique as "Seldom's sprinkle-pass" because that's what it reminded him of when he watched me.

Hope I haven't over-stepped my bounds with this discussion but I figured it's Shop Talk.

By dasimonds (**)

Date 08-24-2001 09:52

Hi Seldom,
Thanks for the tip. Your description of the technique you used sounds similar to the way in which I manipulate stainless SMAW. It is a difficult process to become proficient at. We use it for testing purposes to fill and cap a 2" SCH 160 coupon, but only after it has been rooted and filled half way out with GTAW. I can't say I've ever seen the corporation I'm employed by use Stainless SMAW on pipe in a production environment, even for the filler passes. I think it is mostly related to the fact that some believe that a GTAW joint is somehow "better" than a SMAW weld. I personally believe if the process is correctly applied, according to procedure, there isn't any real difference in the final weldment, other than appearance. I'd like to run one of armywelder's coupons. just because I've never done it before. Again, thanks!
Dale Simonds

By - Date 08-23-2001 12:50

When I broke into welding in the late 60's for Dow Chemical Co., that was the second test you took in becoming a journeyman welder. 2" sch 40 SS coupons, 2G & 5G (6G if you thought you could pass) open root SMAW and radiographed to ASME Sec IX. The nickel base alloy qualifications were the same. Monel was a "toughy" for some!

This test is no longer a "company standard" as it once was but it's still used for very specific circumstances. I know at least acouple of years ago at my plant site they were testing SS SMAW using 6" sch 80 CS coupons, 2G &5G open root GTAW/SMAW. For the smaller diameter qualification they just drop down too 2" sch 80 coupons. Both tests are radiographed.

By pipewelder_1999 (****)

Date 08-23-2001 18:29

I have performed open root SMAW welds on SS on Tangent Tube Composit Waterwall tubes (Window Welds) on Black Liquor recovery boilers. The rods used were 2 MM avesta P5PW I think. Its been awhile.

I prefer the ole GTAW method for all other SS roots.

By - Date 08-23-2001 22:37

Hi Pipewelder_1999
I wholeheartly agree.
Over the years it was determined that not only was GTAW root (SS & nickel alloys) far easier to apply and meet code required quality standards in most cases, but our metallurgists determined through failure analysis that the tenacious slag (internal surface of the root) inherent to the alloy SMAW processes, lead to and promoted localized corrosion in many chemical processes. Thus leading to weld failure and unscheduled plant shutdowns.

By dasimonds (**)

Date 08-24-2001 10:13

Hi again Seldom,
I'm very curious as to root silica, say from unclean TIG wire or base metal, and if it has the same inherent deleterious effects as SMAW root slag, as far as to allow the accumulation of unwanted deposits. The reason I ask is because we predominantly use "Solar Flux" as opposed to an Argon purge(which, by the way, I personally prefer) for open root stainless pipe, which leaves a lot of residue inside the pipe. Does this also apply to carbon steel GTAW root silica as well?
Dale Simonds

By - Date 08-24-2001 12:43

Good morning Dale,

A very good question that should create interest and the intitial answer is yes.

It had been determined by our Materials Dept. that the use of compounds such as "Solar Flux" in many of the plants' chemical processes, would indeed play host to a deleterious enviorment due to the their residuals. These types of compounds were "outlawed" in our plant site. Possibly your company's chemical processes have been determined not be of a nature where corrosion is a concern or the use of the compounds can be controlled. Our plant site has a square mile footprint and enough MSDS sheets to fill a small library (only a small exaggeration) :-)

I don't have a lot of experience with CS, GTAW root silica but the chemical enviorments are going to be considerably less corrosive as a general rule. As kind of an off-hand example, in a cool brine service we would use a E7010-A1 for the root bead because of the moly and that slag would adhere to the root face and the weld/HAZ interface. But it was never proven to have a created a determental enviorment for corrosive attack.

By the way, since I retired I still have contact with most of the mechanical contractrors that service my company and I've not heard that the ban has been lifted.

Have a great day,

By DaveP66 (*)

Date 08-22-2001 21:07

I have used this rod before...not on that thick of SS. I used it on like 8th inch steel...the rod runs nice beads and is pretty easy...just use a dragging motion...the thing that i remember most is that it tends to like to stick and can be kind of stubborn...also seemed to me that this rod is kind of picky on arc lenth...use a short one...but be careful, it will stick fairly easy....and most of all....after you make a pass, and go to chip the slag off...watch out...the flux likes to pop off (literally) you dont even have to touch it sometimes...pieces will just fling into the air....make sure you have some eye protection undernieth your helmet with this rod...i learned the hard way...i useually put my safely goggles on only when im chipping..and weld with just the helmet on...but after like my 2nd bead of the 308-16...some slag popped off and got me on the lip...nice little burn... :)

David