api 5l gr. x60 maximum allowable temperature. 1

[2om]

hi,
as per b31.3 , the maximum allowable temperature for api 5l x60 pipe is 204 c.
can anyone help me to understand the reason behind it?
if we use it for higher temperatures, what are its consequences in a sour services?
regards

 

[weldstan]

It's strength is somewhat due to thermo-mechanical processing and it is lost at exposure to moderately high temperature.

 

[2om]

thanks for the answer.