QW 407.2 Temp & Time range

qaqcmpm · **Joined:** Wed Sep 24, 2008 11:45 am **Posts:** 64

Code:

QW-407.2 A change in the postweld heat treatment (see QW-407.1) temperature and time range
The procedure qualification test shall be subjected to PWHT essentially equivalent to that encountered in the fabrication of production welds, including at least 80% of the aggregate times at temperature(s). The PWHT total time(s) at temperature(s) may be applied in one heating cycle.

In our PQR (45mm thk Plate)
Temperature (range)- 620 Deg C; Time Range - 1Hr/inch

Hence holding time for 45mm is 108 minutes. But in production 38mm to 60 mm for stress relieving- how to establish the time range and can anybody explain what is 80% of the aggragate times at temperature(s) given in QW 407.2. What is the +/- tolerance allowable in temp & time when used in production welds?

raghurambathula · **Joined:** Tue Jan 29, 2008 5:00 pm **Posts:** 103

QW407.2 is applicable if you require HAZ impact tests on PQR.

Time at teperature 80% in my understandung is

if you have PWHT 2 hours on the job. your PQR must have been qualified with PWHT time at least 86 minutes

QW 407.2 Temp & Time range

Who is online