GTAW process regarding change in filler metal

[Naidooru]

Hi all,

Please help with the following understanding. As per QW 404.14 and the essential variable table in section IX of ASME for GTAW process the addition and deletion of filler metal constitutes a requalification. If for example I weld a 304 pipe using a 308 electrode/filler can i then utilize the same wps to weld a 316 pipe using a 316 electrode/filler? Or do i need to requalify? please advise as the same F, A and P number remains the same but the code also says that we cannot just change as we please between base and filler metals.

Ruben
Senior inspector of pressure equipment

 

[XL83NL]

What's the Code of Constructuion youre working to? That should be a first question, as it may put extra requirements on top of those of sect IX.
F and A are essential variables, so they require requalification if they change. If they dont, youre fine in Code terms.
If the product youre making requires impact testing (which I doubt, yet still), suppl. essentials start playing a role and you may require requalification.
Other essentials may play a role;
[ul]
[li]qualified base metal thickness T[/li]
[li]depostied weld metal thickness t[/li]
[/ul]

The list goes on (see QW-256), but im pretty sure these 2 matter the most. Since the details provided are not sufficient, its impossible to answer your question 100%.
But I think youre good.

In any case, reviewing this paper by ASME is useful (for people with your title especially).

 

[SectionIX]

QW 404.14 refers to autogenous (no filler metal added) welding. Hence, the deletion or addition of filler metal.

The example of changing from one filler metal F# or A # to another (if appropriate) would be covered in QW 404.4 and QW 404.5, respectively.

 

[Naidooru]

Thanks SectionIX, that is exactly what i was looking for. I did not see a reference from 404.14 to say that autogenous welding was the actual application of this statement thus where process of elimination comes about this statement hypothetically could refer to different types of filler metal if interpreted so.
I do thank you all for your great insight.

Greetings for the New Year 2015 for everyone from us in South Africa.

 

[weldstan]

ER316 has the same F No and A-No as ER308; therefore, additional qualification is not required unless impact testing is required, at which point AWS Classification is an essential variable.

 

[SectionIX]

Naidooru,

Glad to help! Greeting to you as well.