Mechanical characteristics for pipeline material at elevated temperatures

[nikolastrojman]

Hi!

Does anybody know how to determine the minimum yield strength for pipeline materials like e.g. L360 (or API 5L X52) above 60°C.
As per EN 1594, above 60°C min. yield strength should be corrected taking the temperature into consideration.

 

[LittleInch]

The only graph I can remember is in I think DNV OS F101 for high chrome steels.

Most pipeline codes use 120C as the limit and e.g. BS PD 801 includes the statement
"NOTE The effect of temperature de-rating on the SMYS of carbon steel is included
in the design factors for temperatures up to 120 °C."

If you really wanted to do something I think you would need to ask your specific vendor on his data and / or do some specific tests when you buy the line pipe, not expecting any variance for 5L BELOW SMYS or maybe 1-2% max.

Everything /I can see says 5L doesn't de-rate below 120C, but higher chrome ones, like Cr13 or Duplex do.