Lamination in structural steel 5

[Weldinspect]

Can any one tell me if lamination in steel columns can be repaired?

We had las year a case where about 30% of the material for a project had a few less than 1 mm deepth laminations. There was a lot of discusion and it was decided that they could not be repaired, my personal opinion was that it could be done but a lot of heads ahd the final desition.

Any one had this experience? do AISC allow the reparation of this imperfection?

http://www.luisalbanes.com

 

[Weldinspect]

Here is one picture and the material was ASTM A992

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[mfgenggear]

Op
That appears as Crack, now the entire ru may have
Internal defects. So now can't be trusted.
Return to the supplier for waranty.

 

[Weldinspect]

We done ultrasound and dye penetrant and they didn´t go all the way the thickness, let me show another picture

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[mfgenggear]

Weld
Do you mean ultrasonic inspect. ?
Penetrant is only surface defects.
If it's ultrasonic inspect a ruff surface would be difficult to test.

 

[MintJulep]

Sure, anything can be repaired.

But if cost and risk are considered then repair isn't always the best choice.

Seems like that's what the lot of heads figured out.

 

[weldstan]

The first photo of the flaw is not a lamination; however, it is a rolling flaw which could be repaired. Whether it needs to be is another matter. Futher exploration of the second flaw is needed for evaluation. Could be a seam and may not be deep. Try grinding a portion to determine depth.

 

[Weldinspect]

1. We returned the hole lot
2. Yes ultrasound inspect
3. That was a year ago and my opinion was to repair but the rest of the team did not agree and this delayed the project for more than a month
4. Sorry grinding is not possible any more
5. The factory supervisor came to the project and measured the deepth with and instrument that has a needle and not one had up to one milimeter

Thank you all for your opinions, for me repairing was cheaper than changing the material

http://www.luisalbanes.com

 

[jessieleo99]

While AISC does not provide specific lamination repair rules, the repair is generally possible under certain conditions. However, the final decision should be made based on a detailed assessment by a structural engineer and in line with the project's safety and performance requirements.

https://powder.samaterials.com/

 

[Weldinspect]

Thank you Jessieleo, in this case my opinion was that the repari was possible due to the low deeph of the flaws but unfortunately the rest of the team didn´t agree

http://www.luisalbanes.com

 

[gtaw]

The discontinuity depicted by the first photograph is not a lamination nor is it a delamination. A lamination is a planar rolling discontinuity that lies parallel to the direction of roll and is typically about mid-thickness. It looks like a "hairline crack" that isn't open. If the "hairline crack" opens up such that a piece of paper can be slipped into the crack opening, it is called a delamination. They are usually seen of the face of a cut surface.

AWS D1.1 has criteria for evaluating a lamination/delamination. If it is small, it might be accepted "as is", if it is larger, it can be gouged and repaired by welding.

If the applied load is parallel to the lamination, no harm, no foul. However, if the applied load is perpendicular to the lamination, i.e., in the through thickness direction, you could have a problem.

Best regards - Al

 

[Weldinspect]

Thanks gtaw, actually ourse were not deeper than 0.5 mm so I believe we could have use the structures as they were

http://www.luisalbanes.com

 

[mfgenggear]

OP
I can say that indications can be not visible to the eye. But non the less are there. And can be difficult to find.
If this is a commercial product and the is no safety concerns. Yes use it.

 

[Weldinspect]

Thank you megenggear, as always Eng-Tips is very useful with a great team helping. This case happened one year ago so I should have asked before

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