Repair of Base metal

Date 02-03-2023 19:39

I would use a repair WPS and depending on what shape the gouge is as what prep it might need. If the gouge is really narrow, you would want to widen it to make sure the electrode will get to the bottom, if it's wide, you might not need to do anything but fill it up. I would weld it back up and grind it flush, then use some NDT on it to make sure it is a sound repair. Sounds like MT would be a good choice given the depth of the gouge. Keep a report of the NDT in the project file. D1.1:2015 5.14.8.4 may help.

By 803056

Date 02-04-2023 20:26

Whether a repair is necessary and how it should be accomplished is the purvey of the Engineer representing the Owner.

If you represent the Owner as the Verification Inspector, do not offer advice on the means or methods of accomplishing the work.

Yes, you want to be a nice guy and help where you can, but to interject your opinion to the contractor or to offer advice on how to do a proper repair will incur unexpected legal liability if they follow your advice and the result is not as expected.

As a Verification Inspector, to inspect work that you played an active roll in deciding the means and method would be considered a conflict of interest.

I'm not saying the advice offered by my good friend John is wrong, it is just bad practice to get involved if you represent the Owner. If you work for the contractor, by all means offer a solution to rectify the nonconforming material. John's recommendation is sound advice.

Al

By ididntdoit89 (*)

Date 02-06-2023 14:17

I am the QC manager of the shop that sent this to the field. Everything i could find points to that the EOR is responsible for determining if the base material needs to be repaired and how it should be repaired. Honestly, its so minute that the shop personnel would have simply placed a tack at the site of defect, ground flush, and not tell anyone. Thank you for your advice.

By jwright650 (*****)

Date 02-06-2023 14:40

I was a QC at my former employer, I understand how the shop environment is and the issues that can come up and my advice was based on such. D1.1 also gives details for restoring mill materials or field repairs, restore the piece to be fit for service, keep your inspection records of the repair prior to sending it out to the field.
As for fault if something fails, it came from your shop, so you own it. I feel like if you really were worried about it, you would have replaced the piece. I say restore it back to be fit for service and keep records on it.

By Jovi Zhu (**)

Date 02-18-2023 16:28

By searching the key words “base metal repair" in D1.1 2020 I got the following FYI:

(Stud Welding)
9.7.5 Removal Area Repair. If an unacceptable stud has been removed from a component subjected to tensile
stresses, the area from which the stud was removed shall be made smooth and flush. Where in such areas the base metal
has been pulled out in the course of stud removal, SMAW with low-hydrogen electrodes in conformance with the
requirements of this code shall be used to fill the pockets, and the weld surface shall be flush.

C-7.14.2 Mill-Induced Surface Defects. The base metal to which welds are attached must be sufficiently sound so
as to not affect the strength of the connection. Base metal defects may be repaired prior to the deposition of the prescribed
weld. This subclause does not limit base metal repairs by welding. Defects that may be exposed on cut edges are governed
by 1.14.5.

These are clues that D1.1 Code dose not limit the use of weld repair (buildup) to restore base metal thickness.

Hope this will help.

By ididntdoit89 (*)

Date 02-06-2023 14:17

Thank you sir.

By 803056

Date 02-06-2023 20:27 Edited 02-06-2023 21:03

As the fabricator's inspector, you are in a good position to determine the best approach to repair the member in question. Keep in mind there are minimum weld size requirements to ensure sufficient heat input is used to mitigate the formation of an undesirable microstructure. It is a smart decision not to allow the welder to simply deposit a small weld to fill the void. I would consider using a grinder to remove the defect to sound metal. The excavation should be long enough to put on heat into the base metal to ensure slow cooling. D1.1 calls for a minimum of fillet of 1 1/2-inches, or the weld size is limited to 1/4 the weld length. I would lean heavily toward a minimum weld length of 1 1/2-inches. The weld size resulting from the excavation, lean on the minimum size stipulated for a partial joint penetration groove weld based on the base metal thickness. That would be my recommendation for the minimum depth of the excavation, even if the defect depth was less. Deposit weld to fill the excavation and then grind the weld flush with the adjacent surfaces. The marks left from the grinding should be parallel to the direction of roll unless you know that the primary tensile stress in transverse to the length of the excavation.

The EOR may make the decision to require a repair or replacement, but the contractor is still responsible for the method and means. As such, the contractor must propose the method of repair. The EOR would review the proposed repair submitted by the contractor.

I hope this is helpful.

Best regards - Al

By ididntdoit89 (*)

Date 02-07-2023 19:24

Thank you sir

By SWN1158 (***)

Date 02-16-2023 20:38

If you’re working to D1.1 criteria, you’re most likely working to AISC 360-22 Specification for Structural Steel Buildings criteria as well, so I thought what they have to say might be useful….

“Thermally cut edges shall meet the requirements of Structural Welding Code—Steel (AWS D1.1/D1.1M) clauses 7.14.5.2, 7.14.8.3, and 7.14.8.4, hereafter referred to as AWS D1.1/D1.1M, with the exception that thermally cut free edges that will not be subject to fatigue shall be free of round-bottom gouges greater than 3/16 in. (5 mm) deep and sharp V-shaped notches. Gouges deeper than 3/16 in. (5 mm) and notches shall be removed by grinding or repaired by welding.”

360-22 defines fatigue as the “Limit state of crack initiation and growth resulting from repeated application of live loads.”

The D1.1 references used in the AISC criteria….

7.14.5.2 addresses mill induced discontinuities, 7.14.8.3 addresses roughness, while 7.14.8.4 addresses Gouge or Notch Limitations……

“Roughness exceeding these values and notches or gouges not more than 3/16 in [5 mm] deep on otherwise satisfactory surfaces shall be removed by machining or grinding. Notches or gouges exceeding 3/16 in [5 mm] deep may be repaired by grinding if the nominal cross-sectional area is not reduced by more than 2%. Ground or machined surfaces shall be faired to the original surface with a slope not exceeding one in ten. Cut surfaces and adjacent edges shall be left free of slag. In thermal cut surfaces, occasional notches or gouges may, with approval of the Engineer, be repaired by welding.”