Visual Inspection tooling for titanium weld discoloraution

[Alessandro Lavista]

Hi to everyone!

The following are the reference document for my question

[1] Design and construction rules for mechanical components of PWR Nuclear Island RCC-M Ed. 2007 + Addenda 2010
[2] Approvals testing of welders – Fusion welding – Part 5: titanium and titanium alloys, zirconium and zirconium alloys EN-ISO 9606-5:2000
[3] EWI Titanium Discoloraution card (

https://ewi.org/services/production...ducts/ewi-titanium-weld-color-inspection-kit)

[4] Non-destructive examination of fusion welds - Visual examination EN 970:1997
[5] Non-destructive testing of welds — Visual testing of fusion-welded joints EN ISO 17637:2011
[6] Non-destructive testing of welds - Visual testing of fusion-welded joints (ISO 17637:2016) EN ISO 17637:2016
[7]

http://www.metalspiping.com/how-to-evaluate-titanium-welding-visually.html

I’m following the welding qualification of titanium welding fillet weld in a project governed by RCC-M code [1] and EN standard [2] for welders qualification.

[1] does not provide requirement for acceptance criteria for titanium welds discoloration (section S 7120 for class 1 welds, S 7720 for class 2 welds and S 7730 for class 3 welds)

[2] does provide acceptance criteria in terms of text description as follow

Quote
“Colouration:
accepted colours on weld ,metal surface: silver and straw;
A narrow band of intensive colours close to the limits of the gas shielding is acceptable.
Darker brown, purple and blue colours and grey or flaky white are not acceptable."
End of quote

Without specifying if some tooling (e.g. a set of discoloraution welded coupon and/or high resolution chart as [3]) shall be used.

[2] refer to the EN ISO Visual inspection standard [4] for the method of examination; [4] does not provide requirement nor for weld colour inspection nor for specific tool to be used; even in the standard [5 and [6] that substitute standard [4] there is no requirement for specific tool to be used.

Knowing all the background above, do you know if there are requirement to have a physical set of samples as [3] or I could simply put the pictures of the different discolouration of titanium weld (e.g. pictures that could be found at [7]) in the acceptance critieria section of the visual procedure to be used by the inspector?

Many thanks in advance for all your feedback!

Also some reference about this topic (e.g ASTM, MIL or aerospace standards) for my knowledge are greatly appreciated as well!

 

[SJones]

Is [7] not the same as AWS G2.4? Generally, it's a visual call against good reproductions of the AWS/EWI pictures.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[Alessandro Lavista]

Dear Mr Jones,

many thanks for the answer!

Unluckily I don't possess the AWS G2.4, but your reference allowed me to make further search and updating the Question Reference Document (QRD) as per list below (revion traced with underlined text)

[1] Design and construction rules for mechanical components of PWR Nuclear Island RCC-M Ed. 2007 + Addenda 2010
[2] Approvals testing of welders – Fusion welding – Part 5: titanium and titanium alloys, zirconium and zirconium alloys EN-ISO 9606-5:2000
[3] EWI Titanium Discoloraution card (

https://ewi.org/services/production-services/conso...)

[4] Non-destructive examination of fusion welds - Visual examination EN 970:1997
[5] Non-destructive testing of welds — Visual testing of fusion-welded joints EN ISO 17637:2011
[6] Non-destructive testing of welds - Visual testing of fusion-welded joints (ISO 17637:2016) EN ISO 17637:2016
[7]

http://www.metalspiping.com/how-to-evaluate-titani...

[8] Guide for the Fusion Welding of Titanium and Titanium Alloys AWS G2.4/G2.4M:2014
[9] NASA Process Specification for the Manual Arc Welding of Titanium Alloy Hardware PRC-0002 Rev. D (

https://www.nasa.gov/sites/default/files/atoms/files/prc-0002_current.pdf)

In particular, in [9] Appendix A - WELD ACCEPTANCE CRITERIA, in relation to "DISCOLORATION", there is the following note

QUOTE
Refer to AWS G2.4, Figure 7, for weld color examples.
END OF QUOTE

So I imagine that if the inspector has this figure in place during the inspection in paper or digital format on tablet or smartphone, everything should be fine.

At this point I believe that the best things to do is expose the topic to the customer and obtain a written agreement that the above approach could be used, maybe by the approval of procedure.

Many thanks for the feedback and the reference, it open to me a new path on the subject!