Qualification of Dissimilar Base Metal Thickness with Impacts 1

[DonRoss]

Hi, I'm looking for some insight and or clarification on what the qualified base metal thickness would be with impacts if welding a 0.24" P6-Group 1 plate to a .375" P6-Group 4 plate, single sided butt-weld, beveled accordingly with no taper.

QW-202.4 Dissimilar Base Metal Thicknesses
WPS qualified on groove welds shall be applicable for production welds between dissimilar base metal thicknesses provided:
(a) the thickness of the thinner member shall be within the range permitted by QW-451
(b) the thickness of the thicker member shall be as follows:
(1) For P-No. 8, P-No. 41, P-No. 42, P-No. 43, P-No. 44, P-No. 45, P-No. 46, P-No. 49, P-No. 51, P-No. 52, P-No. 53, P-No. 61, and P-No. 62 metal, there shall be
no limitation on the maximum thickness of the thicker production member in joints of similar P-Number materials provided qualification was made on base metal
having a thickness of 1/4 in. (6 mm) or greater.
(2) For all other metal, the thickness of the thicker member shall be within the range permitted by QW-451, except there need be no limitation on the maximum
thickness of the thicker production member provided qualification was made on base metal having a thickness of 1-1/2 in.(38 mm) or more.

More than one procedure qualification may be required
to qualify for some dissimilar thickness combinations.

QW-403.6 states:
The minimum base metal thickness qualified is the thickness of the test coupon T or 5/8 in.(16 mm), whichever is less. However, where T is less than 1/4 in. (6 mm), the minimum thickness qualified is 1/2T. This variable does not apply when a WPS is qualified with a PWHT above the upper transformation temperature or when an austenitic or P-No. 10H material is solution annealed after welding.

As clarification, Interpretation: IX-04-11 Question 2 reads
Background: A procedure qualification test coupon using the same or different P-Number materials and consisting of two plates of different thicknesses, T2 = 1-1/2” thick and T1 = 1” thick welded with a single process. The thicknesses meet on the same plane with neither plate being tapered.

Does this test coupon qualify the WPS for both base metals for a thickness range of 3/16" to 8" on both sides of the weld joint.

Reply: Yes

As such, if the same rationale is applied to what I intend to qualify, then would it be correct to establish base metal thickness qualification range to be 0.120" to 3/4" as it relates to QW-403.6?

OR

Base metal thickness range for P6-Group 1 is 0.120" to 0.480" and for P6-Group 4 is 0.375" to 0.75"?

Thanks in advance.

Don

 

[aburafdi]

Interpretation: IX-04-11 -- in question 3: when the material are from different P-numbers, then the answer is "No".

Thus, in your case : as you have same P-No, then your qualified thk range is 0.120" to 0.75"

Regards

 

[DonRoss]

aburafdi, I appreciate the response; however, I would think that, because impacts is an essential variable, the qualified thickness would then apply to the Group number and its individual thickness.

My thoughts are, if the HAZ and base of P6 Group 1 is impact tested differently at -20°F and the P6 Group 4 at -50°F, then as I would understand it, the qualified thickness would only pertain to its Group number.

OR

Would it be sufficient to say that, the qualified thickness in combination of the two Group numbers is .120" to .75"; however, the temps qualified to, pertain only to its Group number.

Thanks,

 

[jwhit]

Treat the Group No. as if it were a separate P No. when impacts apply. I'll stay out of the thickness part of this as my head is spinning from other issues this morning.

 

[DonRoss]

Thanks jwhit, this would be easier for my purposes; however, we're not certain about how to treat the thicknesses.

I've requested clarification from ASME, but it's going to be a while to get a reply.

 

[weldtek]

As clarification, Interpretation: IX-04-11 Question 2 reads
Background: A procedure qualification test coupon using the same or different P-Number materials and consisting of two plates of different thicknesses, T2 = 1-1/2” thick and T1 = 1” thick welded with a single process. The thicknesses meet on the same plane with neither plate being tapered.

Does this test coupon qualify the WPS for both base metals for a thickness range of 3/16" to 8" on both sides of the weld joint.

Reply: Yes

It appears that you didn't include all of the interpretation.

Q 3 Does this test coupon qualify the WPS for both base metals of different P #'s for a thickness range of 3/16" - 8"?

Ans: No

 

[DonRoss]

weldtek, thanks for the input.
I didn't include Q3 because I would not be using Different P No's, I would be using the same P-No but different group No's.
The interpretation does not account for impacts as a requirement.
I tried to search for other interpretations similar to IX-04-11 with impacts without success.

 

[weldtek]

As was noted in an earlier response, when it comes to impacts, Group number is an essential variable.
How would you approach this if you were using different P nos?

 

[DonRoss]

I would treat them as being separate, the qualified thickness would be relative to its P No., as clarified by the interpretation in Q3.

 

[weldtek]

Agreed. I look at it this way, in the first case P number is an essential variable and in the second case, where impacts apply, Group number is also an essential variable.

 

[DonRoss]

Gents,

I wanted to follow-up with my response from ASME.
It hasn't been given an Interpretation number yet.

Subject: ASME Section IX-2013; QW-403.6 - Qualified Base Metal Thickness with
File No: 14-1618

Background: A SMAW procedure qualification test coupon consisting of two plates with the same P-Number
but different Group numbers, and of different base metal thicknesses is groove welded. The
thinner plate, T1 = 0.24 in. thick, and the thicker plate, T2 = 3/8 in. thick. Impact testing is required.

Question (1): Does this test coupon qualify the WPS for a base metal thickness range of 0.120 in. to
0.75 in.?

Reply (1): No.

Question (2): Does this test coupon qualify the WPS for a base metal thickness range of 0.120 in. to
0.480 in. for the T1 Group Number, and 0.375 in. to 0.75 in. for the T2 Group Number?

Reply (2): Yes.

Thanks,

Don