ultrasonic testing

By 803056

Date 02-15-2008 04:59

What we have here is a failure to communicate!

I have no idea of what you are trying to describe.

Al

By fbrieden (***)

Date 02-15-2008 06:04

Ditto!

By fbrieden (***)

Date 02-15-2008 06:03

Your wrong for posting your question here at this time. Please rephrase your question and spell properly! Also, to be more professional in your postings(s), do not allow your interest to sound as though you're speaking with another person; you should also keep the system of measurement the same, either all in inches or all in millimeters.

By EVWELDER (**)

Date 02-15-2008 06:42

Forgive me for my post I did not me to to be wrong in asking a question I know it did not come out right I was rushing to post it and did not proof read it especially to a welding Instructor. OK what the question is there is a 2" plate welded vertically to a 1" thick base the 1" base is at a slight angle the the 2" plate needs to be level and not go with the angle of the 1" base what is happening when the welder levels the 2" plate there is about a 3/32" gap on one side the weld will be tested by UT the welder has a concern that the weld will not pass because of the 3/32" gap and does not want to weld it. My question is should he be ok or will the UT not pass. The pieces already have some weld I just need to know if its ok for him to weld?

By Joey

Date 02-15-2008 08:50

You must find out first if you have the approved WPS suitable for the actual joint to be welded and also qualified welders.

Regards

Joey

By ssbn727 (*****)

Date 02-15-2008 13:26

Gotcha fbrieden!!!

"Your wrong for posting your question here at this time." Quote from fbrieden... I seem to remember as if it were yesterday when fbrieden got on my case for complaining about another poster's lack of spelling skills while not placing an apostrophe at the correct location in my own reply... Well fbrieden, here's my turn to correct you!!! the correct spelling should be "You're" instead of "Your!!!" Do you agree??? I thought so!!! This just shows proof that NOBODY IS PERFECT!!! Not even you fbrieden!!!

An old friend of mine once told me that the closest anyone will get to becoming perfect is two minutes after they throw all of the dirt over ones casket in ones grave!!! I asked him in response "Well, what about if the person prefers to be cremated???" He replied " In that case, it's when they put the cover over the urn filled with the ashes of the deceased."

The man was a genius!!! He was also one of the best counterfeiters the ATF had to put up with before the days of digital duplication!!! A tool and Die maker like Dave Boyer and yet, even he wasn't perfect because after all, he got caught being imperfect!!! Therefore, I propose that we all stop being so hypersensitive when someone makes a spelling or grammatical error or two when they're posting!!! At the very least until there is a more thorough spell check function for this forum. ;) Besides, where does it stipulate in the forum's rules and regulations that any person posting MUST be grammatically correct, or at the very least, have perfect spelling???

One can use the option of correcting grammatical or spelling errors by typing their query or response first in a MS Word .doc, and then correct any realistic errors... Once that's performed, one simply needs to copy & paste the .doc over to the text box here... Most of the time it works for me but on some occasions, some mistakes are overlooked by either the person typing or the feature itself... However, some folks aren't "up to speed" in using this option so, if anyone wants to know how the spell check function works in this forum, just look underneath each word after one finishes spelling it... If it's incorrect, one will find a line of tiny red dots evenly spaced underneath the misspelled word. :) :) ;)

Well then, now that everyone is better informed regarding the virtues of being imperfect, let's get back to concentrating on how we can best help out EVWELDER in his query which does indeed lack some very important information required from most of us to realistically provide some guidance or advice so this person can go about completing the project. ;)

EVWELDER! Is there any way you can post some pictures here showing us exactly what your (Correct use of the word!) concern is regarding the gap of approximately 2mm???
Also, we need to know what welding code or standard you folks are working from, welding process, mode of transfer, filler material & diameter, welding parameters, fit tolerances, etc. In other words as much pertinent information as possible otherwise I'm sorry but, none of us can actually read your mind from a remote distance like Tokyo, Japan or next door for that matter!!! I mean, If I or anyone else were capable of that on a consistent basis, we would certainly NOT be in here giving or seeking advice!!! We would be making a ton of money doing something completely different like cashing in on predicting the lotteries, or cleaning out casino's of their cash for a living - if you catch my drift!!!;)

So please send us some more detailed information, and we will try our best to help out if we can. :) :) :)

Respectfully,
Henry

By fbrieden (***)

Date 02-15-2008 16:13

Henry,

YOU'RE the best! I love the busting!

Fran

By ssbn727 (*****)

Date 02-15-2008 20:25

Hi Fran!
You keep me on my toes my friend, and I appreciate it :) :) ;) Thanks!!! ;)

Respectfully,
Henry

By ctacker (****)

Date 02-16-2008 02:30

Henry,
you can go to www.iespell.com and download a spell checker that works on the forum!

By js55

Date 02-15-2008 14:10

The issue for UT is not the gap, but any discontinuities that may exist in the weld when completed. There is nothing inherent in the gap that would prohibit a sound weld as examined by UT, other than the skill of the welder to accomodate the gap. Perhaps your welders concerns are not so much UT but their own skill.

By jwright650 (*****)

Date 02-15-2008 14:27

Does this welder have access to both sides of the joint? Will they be backgouging the root back out? or will all of this be welded from one side only?

By 803056

Date 02-15-2008 15:46 Edited 02-15-2008 15:59

Well we may not have a complete picture as to what the exact situation is, but it sounds like we have a T-joint that is to be welded and then examined with UT.

The joint sounds like it has a tight fit-up on one end and a root opening on the opposite end of 1/8 inch. That is something we encounter frequently in the field.

My next question is "It the weld a complete joint penetration groove weld or a fillet weld, either on one side or is it fillet welded on both sides?

If it is a complete joint penetration groove weld and if there is access on both sides, it is reasonable to weld the joint from one side and back gouge the second side to sound metal and then complete the joint by welding the second side. It would be advantageous to test the back gouge with either magnetic particle or dye penetrant to ensure all unfused portions of the root are excavated before welding the second side.

I have attached a sketch of how I understand the joint is configured. Tight on one end, with a root opening on the opposite end.

If the joint is fillet welded on one side or both sides, any UT will provided very limited information. My UT experience is very limited when it comes to fillet welds. Unless the fillets are very large, I stay away from testing them with UT.

As for the grammar and spelling, big deal! My only concern is that I understand what information the writer is trying to convey so that I have a clear understanding of the problem. We have an increasing number of people from foreign countries participating in the forum. I don't expect them to have a mastery of our language any more than I would have a mastery of theirs. I compliment them on the language skills they do have. My high school Spanish teacher told me to give up Spanish because I would never be able to speak it. So, for you gentlemen oversea that take the time to write to us and ask for our opinions, please don't hesitate to write. There are those of us that participate in the forum that are happy to try to help you, but we may have to ask for clarification so we better understand the nature of your problem. The old adage that "a picture is worth a thousand words" is so true when there is a difference in language and terminology. Include a sketch with your inquiry if possible. It will help us to better understand the nature of your problem.

We can request AWS to list a separate category for those folks that only want to reply to the questions that are grammatically correct. It will be a small but elite group. At least they will be a happy group.:)

Best regards - Al

Attachment: Toyko15-Feb-08.wmf (4k)

Attachment: Toyko15-Feb-08.dwg (25k)

By EVWELDER (**)

Date 02-15-2008 23:36

Thank you 803056 for being professional in trying to answer my question I like to read this forum but what I see a lot of is people getting bashed just trying to get more information and that is not right I understand that my first post for this topic was not clear and I apologize for that. OK going on yes your sketch is pretty much correct the weld is a partial penetration single bevel weld welded all the way around I don't know why it is chosen to ut these welds but I am not from Tokyo I am from Mexico but the code I believe is D1.1. I am sorry for the lack of information let me know if this is enough information or if I just go some where else but thank you once again for trying to help me I really appreciate how you took the time to draw up a sketch. Also everyboby who responded thank you too!

By jwright650 (*****)

Date 02-16-2008 11:48

Fillet welds and partial pens are tricky rascals to UT...you have to have your calibration dead on and you have to have a good understanding of where your sound is going to be able to evaluate what you will see on the screen. Plotting out the sound path on graph paper can help. If the UT machine has the colored legs that is a great help too. I have a USN 58L that has that feature and I have fallen in love with it.

Ignore any of the derogatory posts and keep asking your questions...there are lots of knowledgeable folks here who like to try to help(and the consultation fees can't be beat (read "free" ;-) ))...LOL

By CWI555

Date 02-16-2008 03:24

Better just shoot me now if grammar is a capital crime. I can't swear to this, but my personal experience with JSNDI techs are that their not to swift when it comes to D1.1 UT. Most of them believe the AWS sensitivity setting is to high, and that is reflected in their procedures. If it's a full pen weld with no gap, then no problem, it will come down to did your welders do a good job, and given the information on their procedures, It would usually have to be a fairly gross problem before they would reject it. IF it's a fillet weld on one or both sides, it can be done. However; it takes detailed experience in mapping the joint with ultrasound and detailed experience with the various waveforms and their mode conversions. If I've a choice I would stay away from it, but if it had to be done, I'd want someone with experience in tubular TKY connections. Putting a general asme type or general D1.1 type on it and they will likely reject it when that signal comes back from the root edge thinking it's a crack as on the free edge next to the weld metal at the root (using the angles necessary to bounce it in there) will likely mode convert and show a phase reversal with the echodynamics of a crack. This will further be aggravated by the inconsistency of the root edge, it will be there one second gone the next which typically doesn't make a happy UT tech who then will toss it to be safe half the time. It is this kind of thing that makes most UT types stay away from fillets.
I'd say try to stay away from it if possible, but if it must be done, be sure to get someone familiar with it.

Regards,
Gerald

By Joey

Date 02-16-2008 16:31

EVWELDER

You may want to get advice from your engineering dept to redesign the groove weld design. The weld joint must be accessible to the welder for quality improvement. The redesign should also help to eliminate the difficulties of doing NDT.

Regards
Joey

By 803056

Date 02-17-2008 19:25

It appears that it is unanimous that using UT to examine a fillet welds or partial penetration groove welds is at best difficult to interpret and offers the opportunity to misinterpret the signals on the UT screen.

That being said, there is useful information to be gained by ultrasonic testing as long as all the parties agree to recognize the limitations involved. Using a straight beam from the undersize of the nonbutting member, the bottom member in my sketch, can determine the depth of joint penetration of the weld in the bevel groove to ensure the proper weld size is achieved. Other discontinuities such as incomplete fusion, slag inclusions (if the welding process employs a flux system, and cracks that are perpendicular to the sound path should be easy to interpret. The problems that can be anticipated will be at the root of the partial penetration groove weld and determining where the joint penetration ends. It is in that area that a root crack can be interpreted as the terminal point of the joint penetration.

Again, as long as all parties understand the difficulties and the limitation of ultrasonic examination, there is useful information to be acquired. Some information is better than no information. "It is better than a sharp stick in the eye!"

Best regards - Al