Not logged inAmerican Welding Society Forum
Forum AWS Website Help Search Login
Up Topic American Welding Society Services / Certifications / Guided Bend test specimens and the passage of time
- - By A_DAB_will_do (*) Date 01-10-2014 20:58
There's a question that's been nagging in the back of my mind for several years now.  It's come up again as I recently passed the CWI exam. 

I have seen on a couple occasions the following.  A welder(like me) completes an AWS welder qualification test, prepares and bends the guided bend test coupons under proper supervision.  There a some discontinuities(one or two small cracks at the fusion line or between layers), each slightly less than 1/8" in length, observed in the bend test coupons. They are small enough that they are not considered defects.  Looking at the same samples a day or two later, the discontinuities originally seen appear to have grown in length.  They are now greater than 1/8" in length and are considered defects.  For the sake of argument let's say this test was done with low alloy steel plate(stronger than A36, say with a yield strength in the 50ksi range, and a suitably matched SMAW or FCAW-G filler metal)

What is a reasonable CWI to do in this unlikely circumstance?  How about in a legal confrontation where those same hypothetical bend test specimens are available and become evidence in a trial?  Your report says they passed, but now they do not.

I've not come across anything in the API1104 code that states when guided bend test specimens should be evaluated or how long they need to be retained.  Are their any guidelines in the D1.1 code or ASME codes that touch on this hypothetical scenario?  Has anyone else seen this, and found an fair and ethical response? 

Or am I paranoid, and need to have the doc adjust my meds?
Parent - - By 803056 (*****) Date 01-10-2014 21:28
The evaluation is performed at the time the specimens are bent. The samples are what they are when evaluated. I do not go back a day or two later to see if there has been any crack propagation.

Al
Parent - - By welderbrent (*****) Date 01-11-2014 14:35
Al,

Would this be somewhat the cause of hydrogen and just cooling of the plates if done too soon after the test?  I generally wait until sometime later and often the next day before doing the test on the coupons.  I have not witnessed this type of condition where the dimensions of the discontinuities changes.

Have a Great Day,  Brent
Parent - - By Milton Gravitt (***) Date 01-11-2014 15:21
When I took the CWI exam the question came up there to and it was said not to keep test samples because someone else  might make a diferent call .

                                    M.G.
Parent - - By SCOTTN (***) Date 01-11-2014 17:38
Milton,

I keep all the ones I test because I'm not a CWI and just in case someone questions my experience and whether I'm properly interpreting the results.  I haven't had any issues with any delayed cracking in a coupon so far.

A_DAB_will_do,

You might want to consider having your doctor adjust your meds.  I recently got mine adjusted.  I'm now taking it every 8 hrs. instead of every 4 hrs., so that gives me 4 extra hrs. to get the childproof lid off.
Parent - By A_DAB_will_do (*) Date 01-13-2014 14:20 Edited 01-13-2014 21:06
Will do. thanks.:wink:
Parent - By welderbrent (*****) Date 01-11-2014 20:50
I've heard arguments, discussions really, both ways.  I would think a good photo would be proof enough and then future critical evaluation would be based upon the same thing you saw when the test coupons were bent.

I don't keep mine or any of the ones I do for others.  The paper and my word should be good enough.  Any welder can have a bad day and any customer can request a re-test to work their job especially if the welder's work is questionable.  The question is mostly centered around current work quality to the specifications at hand.  If a welder had a good continuity record (? here we go again) so was easily still current on his certs but after 20 yrs skills have changed, eye sight has changed, ability to keep up with technology is critical, and many other things can mean the welder just can't cut it.  What difference does it make if he, or you, can produce his original test coupons?  He either can or can't right now. 

As to the coupon that comes up with rejectable indications a few days later, was the original lighting sufficient?  Was magnification needed?  Were your glasses placed at the correct distance from your retina to clearly focus on the coupon?  Or, as I suggested earlier, is it possible it did change?  So what.  When it was originally evaluated it was acceptable.  Did hydrogen cause it?  Would it have been discovered if it had been allowed to cool for one or two days before testing? 

Don't know.  Doesn't matter.  Except for personal curiosity to be satisfied.  Information is king.  I want to know.  But, it isn't critical.

Have a Great Day,  Brent
Parent - - By dbigkahunna (****) Date 01-11-2014 22:43
Unless there is a company or contract requirement the specimens are evaluated then scraped. As a inspector, if you wrote it down, it happened. You have the test papers that said you evaluated the specimens and they passed or failed. You have your daily bound journal that has your notes. Besides, if you have the coupons and it is a trial 2-3 years later, can you prove that set of coupons is for that welder?
How?
In my career I have tested hundreds of welders. Both 1104 and Section IX. I have never had anyone ask to see a bent coupon after the test.
Parent - By JTMcC (***) Date 01-12-2014 01:01
Most gas companies keep all of the straps. You stack them in the particular fashion they like, tack them all together and then sometimes tack them to the inside of the test nipples. The whole shebang has the welders stencile on it.

J
- - By A_DAB_will_do (*) Date 01-13-2014 14:19
Thanks all for the insightful replies. 

The question arose when one of the instructors for my CWI prep course mentioned retaining guided bend test straps for 3 years.  When I asked him about this question, the reply was something along the lines of, "Yes, I've observed this when digging though the pile of retained test straps", and "No, it hasn't been an issue (yet)".

I see the logic and sense behind the position that the results are those observed at the time the pieces are bent and evaluated.  However, something tells me that logic and sense won't matter if the issue arises in a legal case.
Parent - - By js55 (*****) Date 01-16-2014 16:28
A Dab,
Bullshyt!!! Toss the F'n things.
Parent - By welderbrent (*****) Date 01-16-2014 16:40
Now JS, tell us what you really think.

:lol:

Have a Great Day,  Brent
Parent - - By A_DAB_will_do (*) Date 01-16-2014 17:52
:lol:  Will do.
Parent - By welderbrent (*****) Date 01-16-2014 19:02
There are very limited applications where it may indeed be prudent to keep test straps.  There is no code guidelines for this.  It would be within company policies and possibly certain government involved situations such as nuclear, NASA, military, etc.  As most work is done to construction trades, either structural, equipment, etc, or pipelines it is really not worth taking up space and documenting for recordkeeping. 

Keeping a copy of a welder's qualification papers (I prefer with a picture to verity id) is sufficient most of the time.

Have a Great Day,  Brent
Up Topic American Welding Society Services / Certifications / Guided Bend test specimens and the passage of time

Powered by mwForum 2.29.2 © 1999-2013 Markus Wichitill