PQR Qualification

[mariocalvo]

Dear all,

I have a question about a qualification of a PQR.
The thickness of the coupon is 48 mm, material is P No3. Our supplier had PWHTed at 610ºC for 1 hour and 30 min instead of 1 hour and 55 min (required for that thickness as per ASME VIII)a second cycle plus 6 hours. The mechanical test are OK (for 1.30 and 6 hours).

Our supplier argues that due to in producction the thickness is 31mm (1 hour and 30min of PWHT), the PQR is acceptalbe.

Knows anyone if the PQR is acceptable?

thanks in advance

 

[stanweld]

Does the vessel and thus the PQR require impact testing? If not, time at PWJHT hold temperature is not an essential variable.

 

[DVWE]

You are talking about 2 separate PQRs, correct?

1 PQR PWHT for 2 hrs (or should have been 2 hrs)
1 PQR PWHT for 6 hrs

 

[mariocalvo]

Thanks for yours responses.

Dear stanweld, at this part it is not requiered impact test.

Dear DVWE, there is only one PQR, with two PWHT cycles, one for 1 hour and 30 min. and then another PWHT of 6 hours for the same coupon.

 

[DVWE]

PQR is acceptable.

 

[Marsart]

Dear all,
I have a question about material ASTM(AISI)1018 low carbon steel, I do not have the code books so I can not verified the C1018. I am not sure what is the letter "C" ? could you someone explain to me what is the letter "c" and what is different c1018 and 1018 please
CF 1018- Cold Forming
HR 1018- Hot Roll

 

[metman]

Marsart,

If memory serves I think C means basic open hearth furnace steel or C for commercial grade but I could be wrong.

If you really need to know the difference of with C designation or without it, I suggest that you start a new thread because your question strays from the subject of this thread.
FAQ731-376: Eng-Tips.com Forum Policies

Cold Forming would usually be taken to mean forming at room temperature. Whereas Cold Finished as used in CF 1018 means Finished rolling is performed below the recrystalization temperature which is "colder" than Hot Finishing or Hot Rolled (HR) which is done above the recrystalization temperature. Some of what I have noted above is merely semantics but I am just being very specific from my understanding of the jargon.