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Up Topic Welding Industry / Technical Discussions / Wed Prep Surface Finish
- - By Jarhead1 (**) Date 01-25-2016 15:00
Good Morning All,
Is there a spec for a 45° bevel weld edge preparation surface finish. The material is 1/2" thk carbon steel.
We are shearing 10' long x 2 edges on 1 pc and getting some tearing that appear to be cracks and spending a lot of time hand grinding, two 10' long edges. Also what is the concavity spec on this as well. If I remember it is .060 d1.1 cant seem to find it.
Quantity's are high.

Thanks in advance.
Attachment: 011.jpg (30k)
Attachment: blades042.jpg (827k)
Parent - - By Lawrence (*****) Date 01-25-2016 15:33
Having a hard time getting my brain around a 10 foot 45 degree sheared beveled edge.

Can you show a pic of the discontinuities ?
Parent - - By Jarhead1 (**) Date 01-25-2016 16:52
see attached
Parent - - By Lawrence (*****) Date 01-25-2016 17:25 Edited 01-25-2016 17:27
Fins!

5.14.2 Mill-Induced Surface Defects. Welds shall not
be placed on surfaces that contain fins, tears, cracks,
slag, or other base metal defects as defined in the base
metal specifications.

I have felt you pain!   A cautionary tale :)
https://app.aws.org/forum/topic_show.pl?pid=267240;hl=Joining%20Flanges%20CJP%20groove%20degree%20included%20angle%20%5c(hand%20cut%20PAC%5c)
Parent - - By 803056 (*****) Date 01-25-2016 18:47
Interesting, very interesting. That would be an interesting photograph to include in AWS B1.10 and B1.11. It is the first photograph of a fin I've seen.

Al
Parent - - By Lawrence (*****) Date 01-25-2016 19:35 Edited 01-25-2016 19:41
Pffft.

Want more?

The Code quote includes fins as "Mill induced defects"  But they can happen during any shearing operation.
Parent - - By 803056 (*****) Date 01-25-2016 20:12
I could use a good photograph for B1.11 Guide to VT of Welds and for the CWI presentation if you don' mind donating them.

I will appreciate the photo as will AWS.

Best regards - Al
Parent - - By Lawrence (*****) Date 01-25-2016 21:26
Those are cell phone pix... But I'm in that very plant next week, so I'll bring my real camera and get you some images.... 

The weld defects are gone... The fins are not  :)
Parent - - By Lawrence (*****) Date 02-05-2016 14:52
Here are some more clear images.

Al, I sent the high resolution images to your email.
Parent - By 803056 (*****) Date 02-05-2016 20:28
I'll take a look. Thanks - Al
Parent - By kcd616 (***) Date 02-06-2016 00:03
Lawrence,
looking at the pics
using an ironworker? for the shearing and punching?
the shear and punch marks to me look like not enough power or tonnage on the machine
might be wrong, but not the first time :red::eek::wink:
sincerely,
Kent
Parent - - By Jarhead1 (**) Date 02-06-2016 17:07
If this is a weld surface., how are you getting rid of these fins or tears machining ,grinding, sanding, etc. What material is this.

We are finding out that different heats from the Mill will effect the shearing of our parts as well. Speeds of our press, lubricant,
strangely duller blade we get a better cut edge for weld prep surface.

Thanks
Parent - By Lawrence (*****) Date 02-06-2016 23:16
I would like to see the shear adjusted to eliminate them... But this particular unit does a wide range of thickness and does not stay where we want it long enough :(

The welders grind off the fins if they are weld surfaces... So like a CJP single pass SAW joint would get ground flush.   Really if the joint face is exposed and will be welded.. That fin is a *defect* and needs to come off.   I learned the hard way about what happens when the welders don't remove them.
Parent - - By jwright650 (*****) Date 01-25-2016 20:35
I remember that thread where you had all that grief with those "fins"
Parent - - By 803056 (*****) Date 01-25-2016 21:29
so many threads, so little memory.

I will put the photos to good use.

Al
Parent - - By fschweighardt (***) Date 01-26-2016 18:55
That shear may need a tuneup
Parent - By mwmw (**) Date 01-26-2016 22:53
That was my thought...time to replace the blades. Or it was pushing the limits of the shear
Parent - - By Jarhead1 (**) Date 02-06-2016 17:16
Gentleman,
Need some opinion(s) on this line on the 45° beveled edge these parts will be going out in the field for welding I did a dye penetrant test and results were this was nor a crack. If you seen this out in the field would this be cause for rejection?

See my original post on top of page.

You help is appreciated.
Attachment: angle3010.jpg (30k)
Attachment: lines027.jpg (631k)
Parent - - By Lawrence (*****) Date 02-06-2016 23:24
I really have no idea what you are talking about.

One image is tiny, the other is gigantic,, There is no arrow or description of what it is you want us to judge and comment on.

But here is a shot in the dark:::     There is what looks like a couple of lines that appear to be from repair welds and have left a lap line after blending.

You are telling us that they did not hold die....  

Ok, they didn't hold die... Why not just blend another 0.010 and make the discontinuity go away... Nominal dimensions are unchanged and whoever looks at it next has nothing to snivel about.

Or you can wait for the complaints to come and tell them that "they didn't hold die" and see how far that gets ya  :)
Parent - - By Jarhead1 (**) Date 02-08-2016 19:41
Lawrence,
Sorry for the bland photos.
Yes, the lines are the issue they are from grinding/sanding down fins or galling from a shearing operation. I did a dye penetrant test and they are not cracks. The problem is we have 4 guys grinding days/nights some remove this line completely and some do not. The edge surface is 10' long on both legs of the angle 20' of sanding away.

The question is are lap lines on a 45° angle surface preparation before weld a cause for rejection not in D1.1 - remember these are not cracks. The problem with removing these lines 100% is they are hard to see and we are double and triple handling 10' long angles 90 lbs each 1000+ per week. All the tedious grinding is non-value added if this lap line/line is acceptable

Thank You -
Parent - By Lawrence (*****) Date 02-08-2016 21:29
That's a really great question.

I suppose the snarky response is... Let's get the upstream processing (shear) working in such a way that the fins go away.

Next would be, if they don't hold die, the discontinuities prolly won't hold contamination.

That being said..  If they somehow do hold contamination they can cause defects (porosity and linear) that can be completely undetectable by visual, but quickly spotted by UT...

More Snark:  4 guys grinding Day and Night  let's say $30 for manpower overhead and 2 eight hour shifts
64 hours a day = $1,920 daily for removing fins.
6 day week = $11,500 per week for removing fins

How much would it cost to get a manufacturer rep in to make that shear do it's thing ?

I doubt anybody is going to notice surface conditions like you showed in the last images  (except guys like Al). 

Just talking about this has my carpel tunnel acting up...... Dat's a lotto grinding friend.
Up Topic Welding Industry / Technical Discussions / Wed Prep Surface Finish

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