Yield strength for P11 at 1050F 1

[corky48]

Does anyone know where to find the yield strength for 1.25 cr .5 mo above 1000F. Table Y in ASME Sec II Part D stops at 1000F

 

[Frank1344]

hi,

I am not quite sure about the yield but you can find allowable stress in the Appendix A of ASME B31.3 Process Piping for over 1000 F.
Also your question made me think, why do you need the yield stress for over 1000 F?
Frank,
Calgary

 

[corky48]

Frank,
ASME B31.3 now allows an alternative allowable stress for occasional loads for temperatures greater than 800F. However it references the yield strength at temperature in Table Y in Sec II Part D. Unfortunately the table goes to 1000F and my line is 1050F.

 

[athomas236]

One of the problems with ASME codes is they do not publish elevated temperature properties, unlike BS, DIN and EN.

athomas236

 

[metengr]

I have several boiler OEM tube brochures back in the home office that date back about 25 years ago or so and contain actual mechanical property (tensile test and creep rupture) data for their tubing material. This was in the days when technical brochures meant something. I can check it tomorrow.

 

[metengr]

For annealed 2.25% Cr- 1%Mo alloy steel;

At 1050 deg F

UTS is 46 Ksi
YS is 22 Ksi

 

[metengr]

For annealed P11 material(estimated);

At 1050 deg F

UTS is 39 Ksi
YS is 16 Ksi

 

[athomas236]

metengr,

You have better records than I do, but may be properties certified by a standard writing body are better than a manufacturers brochure.

Sorry but if ASME wants to be the international standard it claims to be, it needs do to more than just change the words on the cover and leave the rest the same as always.

Sorry

athomas236

 

[metengr]

athomas236;
I agree. I am sure you have heard the expression that once you get an elephant to move you better get out of the way. Well, one of these days I hope the elephant will begin to move.

 

[corky48]

metengr,
Do the YS you have for 1000F and below match table Y? The YS at 1000F is 21.9ksi. The 16ksi seems to be a large drop for 50F.

corky48

 

[metengr]

corky48;
The value I picked off of the graph indicates a YS of 18 Ksi at 1000 deg F for P11 material. Keep in mind that there is variability in properties, and there is no indication if these values were averaged or minimum strength properties. However, the 1.25 Cr - 1/2 Mo steels do see a noticeable drop-off in mechanical properties above 1025 deg F versus 2.25 Cr- 1 Mo alloy steels.

 

[athomas236]

metengr,

Its good to agree.

athomas236