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Up Topic Welding Industry / General Welding Discussion / Surface cavities??
- - By Smokey71 (*) Date 02-01-2007 03:05
Looking for any info on "surface cavities". This is the term i've found in a standard that applies to a job i'm on but i'm not sure on what exactly it is. I would like any info i can get and/or web site where i can find pics showing said cavities. I think I know what i'm looking for but would like some documentation of this defect in the case of review or rejection of welds.  Thanks for any help i recieve!
Parent - By aevald (*****) Date 02-01-2007 03:17
Hello Smokey71, go to the search portion of the forum here and type in "worm holes.....chicken tracks.....?????" You should be able to find a thread that discusses this particular item at length. There are also some links to articles that could possibly document this information for you or at least point you in the right direction. Good luck and regards, aevald
Parent - - By darren (***) Date 02-01-2007 06:07
hey smokey there is a guy named stephan on that thread that will be able to help you for sure, he's some sorta welding consumable super genius. if the answer is not in the thread, then email him directly but be warned your gonna get an answer not a geuss so put on your thinkin beanie.
darren
Parent - - By aevald (*****) Date 02-01-2007 06:37
Good point darren, I believe that stephan can certainly help him out with his question now that you mention it. Regards, aevald
Parent - - By hogan (****) Date 02-01-2007 15:45
is the problem with 7100 ultra?
Parent - - By Smokey71 (*) Date 02-03-2007 20:59
No. Just plain old er70-s3. All parameters are to a wps. 90-10 shielding gas. All material is P&O, wiped down with acetone, sanded with 80 grit to remove any remaining scale from weld zones, wipe again with acetone, and then welded within three hours from said prep. I've noticed this only recently. All parts have heat numbers and purchase order #'s and at the last change of heat #'s is when i notice this phenom. Mill specs o.k.'s the material as required. No change in comsumables. All equipment calibrated as required. Flow rates checked and unchanged. Really stumped. Thanks for all the advice everyone! I'll keep diggin'!
Parent - - By Stephan (***) Date 02-04-2007 17:45
Smokey71,

very interesting!

After I have read what you have explained and as far as I have understood it correctly, the only issue has been changed was the base materials Heat No.(?).

May I ask if you have conducted such a kind of comparison between a piece of "older" or former base material where the phenomenon has not been observed, and the "newer" or current base material where the surface-cavities generation occurred?

For instance by welding a bead on plate under holding all surrounding parameters constant but only changing the base material?

Regards,
Stephan

P.S. A heartfelt "Thanks" for the kind and trustfully words coming from Darren and Allan!
Parent - - By Smokey71 (*) Date 02-04-2007 19:18 Edited 02-04-2007 19:39
All materials from with old heats have been used. All material must meet customer specs. This material is only extruded twice a year by the mill per request of the customer we are building this product for. material is 3/8" wall tube welded to 3/8" wall tube and 1/2" plate. I am the welder and am not involved with the inspection but have been told it meets the mill spec required, passing charpy v-notch. I am a cawi, not practicing, and since taking the week long prep class and test for cwi, have been much more leary when the Q.C. guys sign off with not so much as a comment to some of the discontinuities. The customers standard lists surface and elongated cavities with tolerances and so far the work i've done is to par, but i can't dismiss this problem without knowing the cause, even if its out of my control.  As far as the materials chemistry, i've been told that the customer won't release that info to anyone other than the mill and testing lab. Suppose to be some special material only made for this company. I'm not even suppose to disclose their name.
  A big thank you to all who have given input and direction to find my answer! It's very appreciated!!
Parent - - By aevald (*****) Date 02-04-2007 21:42
Hello again Smokey71, I know that you have looked over a number of post with regards to this problem and I know where you are coming from in regards to your position on this project. When you are the "welder" you sometimes aren't considered part of the loop, but you are definitely considered part of the problem most of the time. Proprietary materials can be a definite pain in the rear for the very reasons you listed, you have the best intentions to help out with solutions but many times you aren't given the information to effect those solutions. In looking back at some of the posts regarding this issue I didn't see shielding gas mentioned, I know that this can be a factor in many instances, you might want to look at this as a variable. Another thing would be the filler material, is there any possibility that the deoxidizers or other components of the filler are compromising the weld? This would be an example of the proprietary nature of the material that you are welding on and how you are minus some possible important information. Maybe the supplier of this material needs to step up and supply some investigation on their own to insure this is not the case. Well good luck on this and keep us informed. Regards, aevald
Parent - - By Stephan (***) Date 02-04-2007 22:25
Allan,

great post!

It would be excellent to be kept informed about the progression of solution in this matter.

By the way, it appears interesting to me that the customer himself has defined tolerances for surface and elongated cavities within his standards.

Who knows what the reason might be for...

Regards to all of you,
Stephan
Parent - - By PhilThomas (**) Date 02-05-2007 02:03
Seems to me that we may have overlooked one important variable.  Given that this is a solid wire application, where the shielding is provided almost exclusively by the gas......are you certain you: a) don't have the gas cup tilted to far, causing air to aspirate in from the back or b) don't have a leak in your shielding gas hose?
Parent - By Smokey71 (*) Date 02-06-2007 00:36
Great input guys, Thanks! To Phil: I run my gun straight with no more than 5 degree lead in. Have done macro etch on flare bevel 1g and fillet 2g in house to same parameters with these angles to document the required penetration and fusion needed with the 90-10 shielding gas used. As far as leaks go, I've ran a flow meter on both my guns ( did i mention i'm running both .045 and .052 dual feed) and both guns are running between 29 and 32 cfh. All ceiling fans have been shut off within approx 100 feet of weld cell and no direct contact with hvac or smoke eaters. I've changed defusers (bernard centerfire set up) and all o-rings (tregaskiss tough gun) with oem parts. And yes the centerfire set up is a Bernard/Tregaskiss crossover design. The phenom occurs with both diameter electrode which makes me believe it's a material issue. I tried to track down any old material with the old heat #'s but all skeletons have been recycled. the amount of discontinuities are acceptable by a mile it's just frustrating when you know you can do better. If i figure it out i'll re post as "no more cavities". I'll check this post in the days to follow. Thanks again for all of your advice, it did not fall on deaf ears!!! Thank you!  Respectfully Smokey 71 of Iowa.
Parent - - By Smokey71 (*) Date 02-06-2007 00:41
Aevald- The customer calls out er70-3. I wish i could run 70-6 as it handles scale better (higher Si and Mn) but i gotta do what the customer says. I agree that electrode change couldn't hurt.
Parent - - By aevald (*****) Date 02-06-2007 01:22
Hello again Smokey71, actually I was thinking along the lines that maybe there was something in the base material that wasn't meshing with the ER70 S-3 filler wire and possibly that was causing you the grief. Anyways hope you are able to pin this down and definitely post any results as they become available. Regards, Allan
Parent - - By Smokey71 (*) Date 02-07-2007 01:37
[deleted]
Parent - By Smokey71 (*) Date 02-10-2007 00:08
TA-DA!!  I got it!! I think ??? New order came in and new material with diff. heat #'s arrived so i beat it to the fab. dept to grab some drops and  this stuff welds like the old heat's. Can't explain it as i'm not privy to the chemistry or tolerences of the metalurgy but was told mil specs were met for crap material so on i go! Not much left of the crap stuff left thankfully!!!! If i can find any make-up varience in material i'll get it out here, maybe one of you guys can pin point the culprit (to much this, not enough that, shoulda used this electrode, Etc), otherwise all i can do is send out a my thanks for all who pointed me in very viable directions! made my job easier and i got a real education from u guys. this was my first post and i really appreciated the help!!! Thanks again and keep your rods dry! Respectfulluy yours Smokey 71.
Up Topic Welding Industry / General Welding Discussion / Surface cavities??

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