PWHT temperature range

[adaz27]

I need to use two seperate PQR's for the welding on a P1 Low temp CS product. PWHT is req. due to the thickness. Impacts req. due to material.
PQR 1 has a pwht range of 625 - 635
PQR 2 has a pwht range of 600 - 620

As impacts are required QW407.2 states that a change in PWHT temperature and time range is a supplementary variable.
The way I see it I will have to conduct supplementary tests on PQR 2 using a PWHT range of 625 - 635? Could anybody clarify that this is the correct route to take. Or if there is any way around having to run supp. tests.

thanks.

 

[metengr]

Please review QW-407.1 (a) only

First, for the PQR, why do you have a 10 deg C temperature spread listed for PQR 1, and a 20 deg C spread listed for PQR 2? If you review Section IX, for P-No 1 base materials you can record the actual PWHT temperature, not a specific temperature range. When you generate a WPS, you can provide the minimum and maximum PWHT temperature range in accordance with the applicable construction code for the P-No material or engineering specification provided the maximum PWHT does not exceed the lower critical transformation temperature.

 

[jai2705]

QW407.2 supplementary variable applies here due to impact test, the code requires the temperature to be "essentially equivalent to that encountered in the fabrication ".

The temperature required for P-1 material is 595 Deg C(min) as per UCS 56,Normally the above clause is more relevant when you deal with Low Alloy steel with Normalized and Accelerated cooling, Q&T etc.

Given the scenario in your question, one PQR should be enough with appropriate temp e.g. 620 Deg C .