Base Metal Thickness Range 1

[5pointslow]

I am preparing a new WPS and PQR for P1 materials using GMAW with impact testing. These are prepared in accordance with ASME Sec.IX.
My question concerns the base metal thickness range qualified. I would like to use the same procedure and PQR to qualify material that is 0.154" thick up to 1" thick or more.
From what i have read, this will not be possible.
If I am correct in this conclusion, can I use two PQRs to increase the range qualified on the WPS?
How do I determine if I use the minimum thickness values of QW-403.6 or QW-451.1?

 

[DVWE]

The first thing you should do when evaluating P-No. 1 materials is see if you can take impact testing exemptions. Review UG-20(f), UCS-67, and UCS-68(c).

If any of those cannot apply, then yes, you are correct, two PQRs will be required for your required range of thickness - see QW-200.2(f). QW-403.6 only affects the minimum range of thickness, not the maximum. You still have to use QW-451 to determine your maximum.

UG-84(c)(5)(b) will guide you for your subsize specimens. Probably not a bad idea to read UG-84 too.

 

[5pointslow]

Does QW-403.6 determine the minimum thickness value due to the requirement of impact testing? If impact tests are not required, do I use QW-451.1 for both the minimum and maximum thickness values?

 

[DVWE]

Does QW-403.6 determine the minimum thickness value due to the requirement of impact testing?

Yes.

If impact tests are not required, do I use QW-451.1 for both the minimum and maximum thickness values?

Yes.

 

[5pointslow]

Thank you for your responses.
For this procedure, we are looking to qualify P.1 Grp.1 material to P.1 Grp.2 material.
SA-516 Gr.70 is the P.1 Grp.2 material we will most likely use.
Can we use SA36/CSA G40.21 Gr.44W as the P.1 Grp.1 material even though it is not impact tested and we will be doing impact testing on the welds?

 

[DVWE]

Can we use SA36/CSA G40.21 Gr.44W as the P.1 Grp.1 material even though it is not impact tested and we will be doing impact testing on the welds?

I'm not so sure I understand that question. Doing a P-No.1 Grp. 1 to P-No.1 Grp. 2 is quite common. But that includes impact testing of both HAZs and the Weld Metal. So you should impact test the P-No.1 Grp. 1 also. As you may know, this will qualify welding to themselves as well as each other (QW-403.5).

 

[5pointslow]

Thats my reasoning for using a P-No.1 Grp. 1 to P-No.1 Grp. 2, to qualify the various combinations.
I understand that the HAZs and the weld metal will be impact tested. SA516 Gr.70N is an impacted tested material. SA36/CSA G40.21 Gr.44W is not.
I would like to know if this matters or not for the qualification.
But i just realized that i could also use SA-516 Gr.55, 60 or 65 for the P-No.1 Grp. 1 material. I am able to get that with impact tests if required.
Does this make sense?

 

[DVWE]

I would like to know if this matters or not for the qualification.

For the qualification it doesn't. But read through UG-84(h)(2).

But i just realized that i could also use SA-516 Gr.55, 60 or 65 for the P-No.1 Grp. 1 material. I am able to get that with impact tests if required.

SA-36 can be ordered with impact testing as an option with the supplementary requirement, similar to SA-516.

 

[5pointslow]

UG-84(h)(2)(c) states that the test plate material must meet the minimum notch toughness requirements of UG-84(c)(4). The only way to verify this is to purchase impact tested materials or have impact testing performed on the material after it is purchased?

 

[DVWE]

Yes. And Fig. UG-84.1 gives your minimum required ft-lb.

 

[5pointslow]

thanks alot for your help.

 

[WeldingPartner]

Hello,
If you like to know more about this topic, you can download an article called "The Impact Testing Enigma AB-511" from

http://www.absa.ca.

The full story....


Good Luck,
Hugo

 

[weldtek]

5pointslow,
Since the ASME Code recognizes that heat input can be deleterious to notch toughness, and those negative effects are greater on thinner materials, many fabricators qualify a procedure with two test assemblies as follows;
1. a thick plate with bends and tensiles only
2. a thin plate with impacts only.
Eg. a 1" plate with bends and tensiles gets you covered up to 2". Combined with a test assembly that is 3/16" thick tested for impacts only, will give you a qualified range of 3/32" - 2".
All essential and supplementary essentail variables must be identical. Heat input is key. Amongst other paragraphs review QW403.6

 

[5pointslow]

Weldtek,

The thinner plate is impact tested because it has the greater chance of not qualifying? If it meets the requirements, it is assumed the thicker plate will also meet the requirements?

The maximum thickness qualified by the 3/16" thick plate would be 3/8". The minimum thickness qualified by the 1" thick plate would be 5/8". Using two test assemblies with these thicknesses, is the range inbetween the maximum qualified thickness of the thinner plates and the minimum qualified thickness of the thicker plates also qualified?

 

[DVWE]

The maximum thickness qualified by the 3/16" thick plate would be 3/8".

No, because you have impact tested only.

The minimum thickness qualified by the 1" thick plate would be 5/8".

No, because you have not impact tested.

QW-401.3 addresses this way of doing it as weldtek has suggested.

 

[5pointslow]

We are having trouble locating 3/16" thick plate material in SA516 Gr.60. Can we purchase 1/4" thick material and machine it down to 3/16" thick? Impact test requirements are the same for both thicknesses, material properties are the same. I see no reason why not, but am I missing something?

 

[metengr]

Can we purchase 1/4" thick material and machine it down to 3/16" thick?

Yes.