Heat treatment of TMCP pipe bends
Heat treatment of TMCP pipe bends
(OP)
Hi all,
I have a doubt regarding post bending heat treatment. Is it necessary to go heat treatment eventhough bend made from TMCP pipes.
Thank you very much for all. Quick response appreciated.
I have a doubt regarding post bending heat treatment. Is it necessary to go heat treatment eventhough bend made from TMCP pipes.
Thank you very much for all. Quick response appreciated.





RE: Heat treatment of TMCP pipe bends
RE: Heat treatment of TMCP pipe bends
In many cases you will significantly change the properties if the bends are tight enough.
You will need a stress relief to restore the material.
Go back to the original process information and see how the alloy needs to be processed.
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Plymouth Tube
RE: Heat treatment of TMCP pipe bends
RE: Heat treatment of TMCP pipe bends
Steve Jones
Corrosion Management Consultant
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.
RE: Heat treatment of TMCP pipe bends
If you want to keep TMCP properties then the max temperature in the bending needs to be consistent with the final HT temp.
If you go any hotter you will just have mild steel.
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Plymouth Tube
RE: Heat treatment of TMCP pipe bends
Yes, this is induction bend only. Bends will be heated up to temperature 900-1050 deg C and Quench at 550-650 deg C.
But according to API 5L cautionary temperature is 550 deg C for thermomechanical controlled or rolled process pipes.
Thanks
RE: Heat treatment of TMCP pipe bends
A star for your comment re induction bend. Tensile properties and toughness properties will be affected. Original TMCP mechanical properties are no longer applicable.
RE: Heat treatment of TMCP pipe bends
This caution is applicable to sress relief PWHT. Once heated to induction bending temperature, the pipe condition is no longer TMCP, the API caution is no longer pertinent, and it's down to the subsequent heat treatment operation to regain the required properties. This should all be demonstrated by destructive testing for the bending procedure qualification. I believe that you are expecting to temper at 550 - 650 deg C, rather than 'quench.' Anyway, whatever you plan to do, those temperature ranges are far too wide for confidence in repeatable compliance with subsequent property requirements. You might like to discuss narrower temperature ranges with the bend manufacturer for more reliable quality control.
Steve Jones
Corrosion Management Consultant
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.
RE: Heat treatment of TMCP pipe bends
Once you go over that you no longer meet the steel specification and you would need to re-qualify the properties that you will have.
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Plymouth Tube