welder qualification ASME-IX 3

[dursosono]

A welder have 3 qualifications as follow (all as per ASME-IX)
1. 6G Uphill, GTAW full, DCSP, pipe 2" Sch. 80 SA312-TP304L, Filler ER70S-G, single V butt weld
2. 6G uphill, GTAW (root 3.0 mm thk) & SMAW (fill-cap 4.11 mm thk), pipe SA106-B Sch 40, filler ER70S-G & E7016, single V butt weld
3. 6G Uphill, GTAW (root 3.0 mm thk) & SMAW (fill-cap 8.13 mm thk), ASTM A200-T9, filler ER505 & E505

My question is this welder qualified for welding P-No. 1 to P-No. 1
1. Pipe SA106-B 2" Sch. 80 GTAW full using filler metal ER70S-G?
2. Pipe SA106-B 2" Sch. 80 SMAW full using E7016 (root) & E7018 (fill-cap)?
3. Pipe SA106-B 6" Sch. 80 GTAW full?
4. Pipe SA106-B 6" Sch. 80 SMAW full?

Thanks for any help

 

[metengr]

dursosono;
First, it is poor practice to mix US customary units with SI units. You must stick with one - so it will be SI.

Now to answer your question - please have a copy of Section IX otherwise you will be lost.

1. Yes
2. No, the SMAW process was qualified with backing after the GTAW weld root. Look at QW-433.
3. Yes
4. No, same rationale as for (2).

Please verify the above, I did not spend time because that is your job to check information.

 

[billMcL]

Re: your #1 qualification:
I am curious what is the application to weld a 300 series stainless steel pipe to pipe weld with an ER70S carbon steel welding rod.

 

[metengr]

billMcL;
Welder performance qualification under ASME Section IX is about a welder demonstrating they can deposit a sound weld. The choice of filler metal on base metal is for base metal and weld metal grouping, and not about actual production welds. So, filler metal selection on various base metals can seem odd combinations but it is only for performance qualifications.

 

[billMcL]

True enough,

But didn't the welder had to follow a qualified welding procedure to weld the stainless pipe to stainles pipe with carbon steel electrode for the qualification test coupon listed?

And since changing "A" numbers are esential procedure variables for GTAW, wouldn't one have to specifically qualify a welding procedure using P8 to P8 with an A1 F6 carbon steel electrode?

So I assumed the welder has a qualified welding procedure to follow to take the test #1 above.

So I was just curious what application one would have that would require going thru the trouble of qualifying a welding procedure for joining stainless to stainless with carbon steel filler?

 

[gtaw]

ASME allows the contractor to substitute certain base metals for another for the purpose of performance qualification.

However, the filler metal F number is still an essential variable for the purpose of welder qualification. The same F number listed by the WPS must be used even if the base metal substitution is made.

Best regards - Al

 

[weldtek]

Notwithstanding the previous posts billMcl raises a valid point.
Welding stainless plates with cs electrodes is poor practice and can have disastrous results due to the effects of weld metal dilution.
Many years ago I witnessed such a weld break apart after being subjected to minimal stress.
Although gtaw is correct in saying that ASME allows for base metal substitution, its difficult to see any advantage in substituting an expensive alloy for carbon steel. Go figure.

 

[gtaw]

I believe the intent is to allow the contractor to substitute a less expensive alloy, i.e., carbon steel, for a more expensive alloy, i.e., nickel alloy, for the purpose of qualifying the welder.

For instance, if the welder is taking a performance test using a qualified WPS for one nickel alloy welded to another using the GTAW process with a F4X filler metal, Section IX permits the contractor to substitute a less expensive carbon steel in place of the more expensive nickel alloy. The carbon steel test coupons would still be welded with the F-4X nickel based filler metal.

The same philosophy permits the welder qualified on carbon steel to weld any combination of alloys permitted by QW-423.1 (listing the substitute base metals) provided there is a qualified WPS for the combination required for production. Keep in mind that the F-number of the filler metal generally cannot be changed when qualifying the welder because it is an essential variable.

However, since we are dealing with ASME, the welder may be qualified for lower F-numbers when the qualification is for F-1 through F-4 (and sometimes F-5).


Best regards - Al

 

[stanweld]

Agreeing with gtaw as to the intent of ASME IX regarding substitution of less expensive carbon steel base materials in lieu of expensive stainless and nickel base alloys; it is not the intent of Code to eliminate STUPIDITY regarding welder qualification on stainless steel base materials with carbon steel filler metals.

 

[billMcL]

My only point was that Section IX does state "The performance Qualification test shall be welded in accordance with a qualified WPS (except when preheat or post heat is required, as that may be omitted).

I agree that material substitutions are allowable as long as there is a Qualified WPS to support the substitution.

 

[vanci]

Substitutions are allowable (QW-423.1)but why would you want to use a more expensive base material for qualification? I have seen some shops use carbon steel plate with stainless filler for some welder quals. because carbon steel is less expensive than P8. It doesn't make sense to do the inverse.

Also check out QW-433.