Bend Test Results Help Needed

Date 02-10-2016 23:27

Needs a retest as the weld is not even close to being centered on the bend. And if it cracked with such reduced stress from a misplaced bend, guess how bad it would have been if performed properly.

He Is In Control, Have a Great Day, Brent

By jshot

Date 02-10-2016 23:41

This is a single bevel horizontal test. The convex surface is centered from toe to toe. Any thoughts being I've provided that information?

By Lawrence (*****)

Date 02-11-2016 00:04

I can't quote at the moment, but the aera you are to examine is the "convex" surface of the bend coupon, which appears to have less than even 1/8" cracking.

The sides of the coupon are just not within the scope of the inspection.

Pass.

By jshot

Date 02-11-2016 00:20

I'm reading the code and it's just mindboggling to me because of the convex surface and the 1/8th max vs 1/4th. I have hesitated that the 1/4 may go down the side (3/8th portion) but code does not reference that, (I beleive) only the surface..

I feel it passes as well because reading the "Acceptance Criteria for Bend Tests" multiple times. It falls in the 1/8th max range because the heading states convex surface.

By pipewelder_1999 (****)

Date 02-11-2016 18:47

That appears to a discontinuity related to fusion/penetration at the root. It is also a corner crack.

That discontinuity could possibly be observed prior to bending after backing is removed.

"The weld root for CJP groove welds shall be inspected and shall not have any cracks, incomplete fusion, or incomplete joint penetration"

I can't see I side the opening however if it revealed no tearing or stretching, the above defects mentioned would apply.

Just an opinion and subject to being wrong. That's how I would call it.

By Lawrence (*****)

Date 02-11-2016 19:50

If the crack exceeded 1/8" I would reject and base it on the visible fusion issue on the side. Not allowing the 1/4" corner crack allowance or a second sample.

But it appears to have less than 1/8" on the inspected surface... So Pass :)

But the coupon is a side bend, so both root and face are being evaluated on the "convex" surface of the guided bend sample

By pipewelder_1999 (****)

Date 02-12-2016 10:47

Hmmmm. My thought is that if incomplete fusion is visible at any stage while inspecting it would be rejectable based upon the criteria listed in my previous post.

When I have cut straps I have noticed a line at the back side of the joint . I think it's LOF however cannot verify it visually (could be undercut or a rolled edge). When I bend the strap, if I see the in fused edge of the plate I reject it. I have had some where they did not open enough to see this and accepted them provided the dimensions were acceptable.

I will ponder this more though.

Have a good day Lawrence.

By Golden Arm (*)

Date 02-13-2016 20:44

My 2 cents... if I have a strap where there is a crack on the edge such as yours I disregard it and continue to bend the remainder of the welder's straps. When that's all done I put the cracked one back in with the legs inside the jig and bend it to failure then I look at the broken surface to see if there is porosity, slag or whatever in there. I make my call after that provided the remainder of the straps bend good.

By welderbrent (*****)

Date 02-11-2016 02:32

Well, I CAN quote my reasoning and I will 100% stand by a FAIL for this coupon:

D1.1-2010; Clause 4.9.3.1

"the specimen shall be placed on the die member of the jig with the weld at midspan...The weld and HAZ shall be centered and completely within the bent portion of the specimen after testing."

The key words being 'SHALL' used twice in this context.

Don't know how one could call it anything but a retest. The crack has nothing to do with it.

Now, IF the weld and HAZ had been centered as demanded by the code and the crack had turned out as in the picture then I would agree, it would be a PASS. But, the crack has nothing to do with it and the poor welder is subject to a poorly run test by a testor who did not properly see to the required bending of the coupon.

RETEST. NO OPTION to consider the crack.

He Is In Control, Have a Great Day, Brent

By jshot

Date 02-11-2016 03:01

Hi Brent, I really do appreciate all the help with this from you and others. I am kinda second guessing myself because of the type of crack and location and understanding the code due to this being a crack that's not common in my very few WPQ's I've administered. I've got another picture if you don't mind giving me some input. I feel this is midspan and on center. If this was a Vee Groove, there would be no doubt on it being off center, but this is a thick single vee and I hope I'm ok on the centering in the pic. I do value everyone's thoughts and I'm trying to ensure myself of the outcomes.

Thanks,

Attachment: Capture.PNG (235k)

By welderbrent (*****)

Date 02-11-2016 03:40

From the earlier pics I would have said it was more to the side by a considerable distance but the current pic with your lines to indicate the weld location would put it much closer to center position than I thought. While it may still be slightly off center you could well be correct that it is not far enough off to disqualify it on that basis.

Thank you for the additional pic.

Corner/edge cracks are due some consideration but unless larger than this one are generally discarded and not of consideration.

It is hard to make these judgement calls from pics, that's why inspections are not to be done, for the most part, from pictures taken by someone else and sent to you.

But I will agree that this one does appear to be acceptable.

Brent

By jshot

Date 02-11-2016 04:00

Yes I agree my original pictures did not show that great. I am thankful for your input and quick response. Took me many times of reading the criteria but hearing from you all has helped tremendously.

Thanks

By jwright650 (*****)

Date 02-11-2016 11:48

Is the corner crack on the unprepared side of the groove weld?(straight side)

regardless of the reason for the corner crack, it appears to be less than the rejection criteria spelled out(max 1/4" or max 1/8" if due to an inclusion or lack of fusion: Clause 4.9.3.3(3). If it is questionable due to placement of the bend(looked centered to me though) or possibly something due to the preparation of the coupon, it is within the code to cut another sample from the same coupon and see if it yields better results without the corner cracking.(last paragraph in 4.9.3.3)

By jshot

Date 02-11-2016 13:28

Yes, it is on the straight side. Thanks for the information.

By 803056

Date 02-11-2016 22:37

A crack means the weld completely penetrated the joint and was properly fused. A small stress riser, i.e. slag inclusion, incomplete fusion, etc. can cause the metal to fail, i.e., crack when it is bent.

The photograph indicates the root bead did not properly fuse to the groove face. So, if you have to sign the test report you can defer to the code that says 1/8 inch is the maximum if there is evidence of slag or fusion type discontinuity.

Personally, I would make the bum retest.

Best regards - Al

By jwright650 (*****)

Date 02-12-2016 12:00

A guess it could be one of those judgment calls :razz:

....hard to tell from the pictures over the internet what the situation is/was. If I had the bend strap in hand or saw the strap being bent and watched the discontinuity open up so I could make a better decision, I may have asked the bum to retest too... :evil:

When I was a QC, I had several guys retest for less than that, I just wanted clean samples from my guys who were welding on the shop floor. Mainly so I could show them off as discussion pieces(actually bragging on my guys), when visitors were in my office...LOL