New PQRT for 17-4PH: Charpy Required?

[tc7]

I will be working on two new WPS's soon, something we have not done for quite a few years. One is for GTAW of 17-4PH to itself and the other will be for GTAW of 4130 to itself. Applicable codes will be AWS D1.1 as well as Navy requirements for both.

When must PQRT include CVN? There is a lot of discussion in Eng-Tips archives regarding impact testing (CVN)when applying ASME codes, but very little discussion (none that I could find)in regard to AWS requirements.

AWS D1.1 seems to have a casual approach to CVN, relegating it to the customers responsibility: paragrtaph 4.1.1.3 stipulates, "when required by contract documents"; paragraph 4.7 states, "when CVN is specified"; paragraph 4.33 again states, "when specified in the contract documents".

The Navy requirement for Charpy testing seems to be based on if the material is over 1/2-inch thk AND if the specific material specification AND if the filler metal specification both have impact requirements.

In the case of my 17-4PH spec (ASTM A564) it also has the blurb, "impact requirements shall apply when specified in the purchase order". For my typical 4130 spec (AMS 6350, also Mil-S-6758) I find no mention of impact or CVN.

Now for the ER70S rods, the AWS A5.28 has all manner of mention for impact requirements (I don't know what filler we'll be using for the 17-4PH weldments yet) but it would seem to me the requirements in AWS A5.28 are there to qualify the filler to AWS A5.28, not for me to qualify my new WPS!!!

All this background to ask one simple question-
What guidance is standard when deciding if PQRT's shall include CVN?

Thankyou in advance.

 

[metengr]

tc7;
My answer below is not meant to be a smart a## response to your question. It really boils down to the customer or client's engineering specification (unless of course, the applicable Code or Standard provides a basis or rationale for CVN testing).