Dear all

1. For P.NO.5 A, 5B Gr.No.1 (thickness is 5 inches), minimum hold time during final PWHT of actual job at 675 deg C is 5 h as per Table UCS:56.

2. We are carrying out intermittent treatments during rolling etc - Totally 4 cycles at 650 deg C for 2 hours in each cycle

3. We are interested in simulating all the above ( more than 480 deg C as per UCS-85) in the test specimens.

4. Test specimen : Table UCS:56 note 3 indicates at 650 deg C , the specified holding times shall be multiplied by 4. This means 8 hours of intermittant treatment at 650 deg C is equivalent to 2 hours at 675 deg C. Thus net hold time for test specimen is 7 hours ( 5 hours for final treatment as specified in step 1 and 2 hours equivalence for intermittent treatment)

Comments are requested from experts on this interpretation or procedure of arriving at hold time for heat treatment simulation considering intermittant and final heat treatments for the job.

_________________
R.SRINIVASAN
Sr. VICE PRESIDENT
Head, Design and Engineering
PED,ISGEC,
YAMUNANAGAR
HARYANA -135001
INDIA

Dear Mr. Srinivasan

We can't mix two different issues here
Simulation is what we do to know the condition of material after HT, and it has be exact replica of the HT cycle. in your case the test coupons must simulate with 650 °C x 2 hours with 4 seperate cycles + final PWHT + atleast one PWHT cycle for possible repair.

Note 3 is only for alternate PWHT when it is not practcal to do at 675 °C and not for simualting the test coupons (for e,g when u have P8#P5 weld we may use this note for final PWHT)

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Raghuram