Impact test excemption curve for SA-350-LF2

[mechmania]

Which impact test excemption curve SA-350-LF2 belongs to in UCS-66,2007 ASME Section VIII?The notes for the figure imply that forgings not listed would have curve B as applicable.

Is this correct for SA-350-LF2??

Thanks

Hiren

 

[metengr]

mechmania;
Yes, see Notes (2) and (3) in UCS-66. Material furnished under SA 350 is produced to a fine grain practice and is normalized or normalized and tempered or quenched and tempered.

 

[mechmania]

metengr,

Then according to Fig UCS 66(Edition 2007 page 173 Sec Viii Div 1) note (2) and Note(3)(b),Should not the SA-350 be under Curve C instead of Curve B,as SA-350 is produced to a fine grain practice and is normalized or normalized and tempered or quenched and tempered?

Thanks

 

[SnTMan]

mechmania, SA-350-LF2 is impact tested per spec at -50 deg. F., and can be exempted to -55 deg F. per UCS-66(g). If you are perhaps trying to go lower than this, its basis before applying exemptions, such as per UCS-66(b) is -55.

Regards,

Mike

 

[metengr]

First, there are two Classes of SA 350 LF-2; Class 1 is required to be impact tested at -50 deg F, and Class 2 is only tested at 0 deg F.

Second, regarding the impact curves and material, Curve B is applicable. If you read Note (2) in (b) of Figure UCS-66, there is specific reference to material product forms; "all pipe, fittings, forgings and tubing which are not listed for curves C and D below", the Note that might be confusing you is 3 (b) for Curve C material.

 

[SnTMan]

metengr, correct, I tend to forget about Cl 2.

Regards,

Mike