Temperature range for carbon steel, stainless steel 2

[JediInTraining]

At my current workplace I have been tasked with reviewing some piping specs and had some questions with regards to temperature ranges.

1) For standard temp carbon steel specs it is listed as -29 to 427 deg C (-20 to 800 deg F). The upper limit seems quite high, and I know a couple of other organizations I have dealt with only go as high as 300 deg F and 650 deg F. I had heard that creep is a concern for carbon steel for temperatures over ~700 deg F. Is there anything else I would need to consider in selecting the maximum temperature limit?

2) For stainless steel specs there is a range of -120 to 350 deg C (-184 to 662 deg F) for 304L. Other specs I have seen have temperature ranges of -103 to 302 deg F with 304L, and -50 to 300 deg F with 316L. I could not find anything in B31.3 that would suggest how these temperature ranges were originally selected

Any assistance would be greatly appreciated

 

[metengr]

JediInTraining;
Well my young Jedi apprentice, before you can become a Jedi, one needs to use the force to find the answers to your questions below;

1) For standard temp carbon steel specs it is listed as -29 to 427 deg C (-20 to 800 deg F). The upper limit seems quite high, and I know a couple of other organizations I have dealt with only go as high as 300 deg F and 650 deg F. I had heard that creep is a concern for carbon steel for temperatures over ~700 deg F. Is there anything else I would need to consider in selecting the maximum temperature limit?

Besides creep deformation (time dependent damage mechanism) at or above 650 deg F, one needs to be concerned with another time dependent damage mechanism called graphitization. You can perform an Internet search to discover this damage mechanism.

) For stainless steel specs there is a range of -120 to 350 deg C (-184 to 662 deg F) for 304L. Other specs I have seen have temperature ranges of -103 to 302 deg F with 304L, and -50 to 300 deg F with 316L. I could not find anything in B31.3 that would suggest how these temperature ranges were originally selected[/quote]

The maximum temperature limitation is based on tests conducted and reviewed by ASME B&PV Code, Section II. For the L grade of stainless steels, these are lower carbon content, and as such, are limited in elevated temperature service because of creep deformation concerns. You would be wise to follow the above specification requirements.

 

[SJones]

Since you show 'Petroleum' as your discipline, you may wish to review API RP 571 to ascertain the degradation mechanisms and their temperature limits which may apply in operation at the 'workplace'. This will help to establish a 'service index' for the piping specifications.

Steve Jones
Materials & Corrosion Engineer

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