Finding a carbon steel weld in stainless

By hogan

Date 08-26-2008 14:21

no. can you give a little more info? perhaps how this question came about.

By johnnyh (***)

Date 08-26-2008 14:33

ooooops

By vagabond (***)

Date 08-26-2008 14:54

I don't see how RT would indicate type of metal, I would guess you'd need to do a PMI. Of course you could probably tell visually if it was carbon or stainless. Although I had a guy weld on a flange the other day that was carbon and it was shiny enough to be SS. I only caught it by checking the numbers. If I went by looks alone I would have swore it was stainless too.

By Mikeqc1 (****)

Date 08-26-2008 15:45

i was thinking minor changes in density but looking at some numbers i see that the difference is not all that great.
MDK

By Mikeqc1 (****)

Date 08-26-2008 16:51

so if the contamination was exposed to the surface a hand help PMI should do the trick?
MDK

By hogan

Date 08-26-2008 17:11

if contamination was exposed to the surface than copper sulfate would work, and is much cheaper than pmi. both would work.

By michael kniolek (***)

Date 08-27-2008 02:03

dosent a PMI use x-rays to produce secondary x-rays on the material in question?

By Mikeqc1 (****)

Date 08-26-2008 15:35

This is actually a Question I have seen elsewhere, I found it interesting, and was wondering.

By rodofgod (**)

Date 08-26-2008 16:08

Hi All!

Been away from this forum for a while now, glad I re-found it!

Anyhow, whilst I'm no rad expert, the large engineering company that I used to work for spent a lot of time, money and effort trying to answer the same question. The problem was at a nuclear power station and it was suspected that 'rouge' weld metal had been deposited in some heavy wall stainless headers.

We had welders welding big stainless 3" thick 'J' prep'd plates with the correct S/S consumable and then depositing carbon steel weld runs in the middle so to speak which were recorded for position etc. These were then sent to the in-house NDT team who had to try and find the artificially created 'rouge' material! Can't remember to many details but after much trail and error and several weeks of work, the project was deemed a success and the company went on to find, excavate and re-weld several areas of the Headers.

So, yes it can be done!

Regards

By hogan

Date 08-26-2008 17:13

that sounds more like eddy current

By rodofgod (**)

Date 08-26-2008 17:28

Hi All!

hogan, No was Radiography.

Regards

By hogan

Date 08-26-2008 17:52

this would be a good one for CWI555

By RANDER

Date 08-26-2008 17:54

Haven't you heard? He doesn't know what he is talking about!!!

:) :) :)

By raptor34 (**)

Date 08-27-2008 00:37

I dont think that any typical tech could decern the difference, i know in the film interpritation classes i went to that issue was never covered so if i was asked to x-ray something and tell if there is carbon steel in the stainless i would tell you you were retarded and to get a pmi. although if there is a way to tell the difference someone please let me know.

By Root Pass (***)

Date 08-27-2008 02:39

What about using a magnent?

By Kix

Date 08-26-2008 18:05

Yeah, I saw a guy put a 6010 root in on a 304 stainless pipe.. ooops

By js55

Date 08-27-2008 13:39

Yes, Geralds would be a very valuable input for this question.
If I may put in my input however, you could do it with UT but it seems to me (and I will leave this clarification to the actual UT guys) it would take a great deal of calibration determine specific TOF for the two materials and a great deal of accuracy to measure the variance, or am I off here?
RT can't do it.
And PMI is based generally upon X-Ray flourescence. Makin the atoms glow essentially and reading the light. Again, I'll bet Gerald, hogan, or NDTIII (and others) can do a much better job of explaining this one.

By Stephan (***)

Date 08-29-2008 16:25

Jeff,

don't want to line-jump here before Gerald and the other great ones in NDT as you have listed them below may clarify this finally.

But forgive me when I admit to be (again) confused - hopefully this won't get to be regular - by reading the post coming from rodofgod - in my eyes an excellent one by the way, since based upon own practical experience - who said:

/quote/

"So, yes it can be done!"

/unquote/

and then reading your post - even as well excellent - saying:

/quote/

"RT can't do it."

/unquote/

Hmmm...

You know what I mean?

Even though I know that it's hard sometimes by knowing that asking two experts may lead to three opinions :-) I nonetheless would like to ask:

Is it... or is it not?

Thanks and best regards,
Stephan

By raptor34 (**)

Date 08-29-2008 17:03

i had a welded try welding a carbon pipe with a stainless hot pass to see what i could tell and i could not tell that it was in there, now i know it is the opposite of what we are asking but i figured it would help. I shot it with a D4 film and ir-192.

By Mikeqc1 (****)

Date 08-29-2008 17:10

CANT WAIT FOR THE RESULT!

By ctacker (****)

Date 08-29-2008 23:57

you might have to read it twice as I have, the result is in there! :)

By Stephan (***)

Date 08-29-2008 17:51

raptor,

great!

There's nothing like the trial!

Best regards,
Stephan

By rodofgod (**)

Date 08-31-2008 16:08

Hi All!

raptor, nice try but that was really a non starter, one pass of Stainless weld deposit as the 'Hot Pass' would be diluted by the root weld deposit and any further fill passes. Making any differential between the materials radiographical density impossible to detect. The tests that I was involved in called for 'rouge' material weld deposits of many cubic inches! Imagine forming a nugget of carbon steel inside a block Stainless, or visa versa.

Regards