PWHT Cycle Of P335-P5B (P9)

[Mostafa Kamel Hussein]

Dear Sir

Really now we are in critical situation regarding PWHT of A335 - P5B (Grade P9). The cycle in brief as attached. first preheat at 200°C then cooling to ambient temperature (20-80°C) for minimum 30 minutes as holding time. after that PWHT cycle starts by heating rate of maximum 100°C /hr till reaching to soaking temperature (704-760°C) for 2hrs. finally, cooling rate of maximum 100°C /hr.

My question is: it this PWHT cycle for P335-P9 true specially cooling to ambient temperature (20-80°C) as i know it's may cause delay crack?

and if this cycle wrong, can you provide me with the correct one which i can built PQR on it?

Your quick reply is highly appreciated.

Regards,

Mostafa K

• 
  

[dilintas]

You have to allow martensite to formally and at the same time avoid cold cracking. Therefor keep the 200 degC for 2 hours and then proceed as you propose

Sent from my Samsung Galaxy smartphone.

[Kannayeram Gnanapandithan]

u have to keep below Mf temp for sufficient time to form tempered martensite say below 120 degree celsius

THANKS & BEST REGARDS,

KG.PANDITHAN, IWE,  AWS-CWI, CSWIP 3.1,

CONSULTANT-WELDING & QUALITY

Mobile no: +919940739349

On Tue, Jan 17, 2017 at 8:18 PM, dilintas <dili...@gmail.com> wrote:

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