Casting equal to P92 pipe or F92 forgings 2

[peaseman]

Does anyone know of a casting material specification which is equal to P92 pipe or the ASTM A-182 F92 forging specification?
Thanks for your help in advance.
Peaseman

 

[metengr]

The P92/T92 and F92 specifications of grade 92, which is an alloy that is a modified version of grade 91 (except the Mo was reduced from 1% to 0.5% and in its place was added 2%W,with minor amounts of V and Nb) were accepted by ASME B&PV Code as a Code case. The P92/T92 alloy was developed by Nippon steel (NF616). Based on this information, I do not believe that there is a comparable casting specification thru ASTM or ASME at this time.

 

[peaseman]

metengr,
Thanks for the info. Could you please provide me with the Code Case number?
Thanks

 

[metengr]

peaseman;
Sure, the ASME Code case number is 2179-3, with an expiration date of 10-2-05. The code case applies to seamless 9Cr-2W tubes, piping and forgings. Supplied as normalized and tempered or quenched and tempered with a maximum hardness of 250 BHN.

 

[Raaden]

metengr;
I guess that the code case you mentioned lists the max allowable stress values, if so could you give me the values at 575°C and room temp.

Thanks

 

[davefitz]

In addition to the info from Meteng, there is some concern with room temp ductility for P92, and this would be worsened for a cast form.

From P J Ennis "creep strengthening mechanisms in 9-12% chromium steels" 2004,regarding P92 after exposure to service temps above 600C, "Although not seeming to have a detrimental effect on creep rupture strength ( indeed W additions are beneficial for the long term strength) the rather large Laves phase particles are responsible for a loss of room temperature ductility and impact strength"

 

[metengr]

Here is the info you requested;

Allowable stress @ RT
25.7 Ksi, tube/pipe and forgings

@1050 deg F (566 deg C)
17.2 Ksi, tube/pipe and 16.6 Ksi for forgings

@1100 deg F (593 deg C)
13.6 Ksi, tube/pipe and 13.0 Ksi for forgings

For your specific temperature you can interpolate the value.

 

[rorschach]

Be aware, that if this is for ASME/API flanges they MUST be forged. Casting is not allowed AFAIK.

 

[GRoberts]

Rorschach,
I've seen a lot of cast flanges used, but not sure which code. Where is the ASME and API requirements to use forged flanges?

 

[metengr]

GRoberts brings up a good point, as far as I know ASME Section VIII Div 1 permits the use of cast flanges.