WELDING PROCEDURE QUALIFICATION FOR WELDING WEAR REPAIRS 4

[falco]

Hi everyone
I'd like to know your opinion for the following case:
I'm quite familiar with the elaboration of documents such as WPS or PQR and WPQR when using for example ASME code SEC IX or AWS D1.1 concerning pressure vessel or steel structure erection. I have a collegue that consult me what happens with weld related to wear repair, this company has some shaft that normally are reconstructed using submerged arc welding and they are having some troubles because it does not last what his supplier is saying. I haven't found yet a specification that suggest me which would be the appropriate test to perform (Tensile bending etc...) and what kind of coupon should be used in order to perform a welding procedure qualification for this type of repairs..
Anyone can give me an advice on which specification or document should I use to elaborate WPS, WPQR and PQR for this procedure and ensure good welding quality
I will really appreciate your assistance
BEst regards

 

[DVWE]

ASME IX, QW-216 and QW-453 give the guidelines for testing required for hardfacing. A hardness test is required, so I would believe that is the important information to know. The customer should provide minimum hardness values to be met.

 

[metengr]

The key with application of hardfacing is to assure complete fusion between the hardfacing overlay and substrate. Hardness test is one method but so is examination of the fusion zone. This should be done by ultrasonic testing of a completed coupon along with cross section of the coupon to perform hardness and liquid penetrant testing.

 

[Metalmeister]

ASME Section IX, QW-453 details requirements for qualifying hardfacing overlays. Surface hardness tests at the minimum qualified overlay thickness is a more useful measure since that is the surface that will see the wearing service. Also, you need to do a chemical analysis from the same location. The code does not require UT but does specify LP. Bend tests are not required and I doubt if you would pass them.

 

[metengr]

Metalmeister;
The requirement for UT is what I normally specify for rotating equipment shaft restoration including the application of hardfacing on a shaft.

The qualification of weld procedures is proper but when it comes to execution, you need some form of NDT to assure adequate fusion with the substrate. This is why I singled out UT in addition to sectioning the coupon and performing all required tests as part of the procedure qualification in accordance with Section IX.

 

[Metalmeister]

Metengr,

Thank you for your explanation. My thought is that if the LP is good on the edges, it is probably good underneath, especially if you examine the cross-section sample of the PQR. Trying to distinguish the fusion line reflection from a small lack of fusion would require much experience and special UT setup, espcially if the overlay is only 100 mils. But you make a good point.

 

[SJones]

AWS D14.6

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[falco]

I'd like to thanks all of you for this valuable information, we will proceed with hardness and UT, PT for the edges to ensure good quality, and also we wil get AWS D14.6 seems to have additional requirements.
Thanks again for your assistance

 

[hogan666]

Additionally, I have seen the use of UT in conjunction with magnetic lift off (MLO). The UT will help determine if there is an adequate bond and the MLO will give you an idea of the thickness of overlay. This is common in tube cladding.