INFORMATION ON ASTM A350LF2 MATERIAL 2

[kkdesai]

DEAR SIR/MADAM,
HELLO! UNDERSTAND THAT UNDER ASTM A350LF2 CLASS MATERIAL, THERE ARE TWO SUB-CLASSES HAVING DIFFERENT OPERATING TEMPERATURE RANGES. I WOULD LIKE TO HAVE MORE DETAILED INFORMATION ON THIS ASTM A350LF2 SUB-CLASSES IN PARTICULAR TO TMEPERATURE RANGES. WITH BEST REGARDS.
YOURS TRULY,
K.K.DESAI, kdesai_@hotmail.com

 

[metengr]

These are Classes not subclasses. The differences between Class 1 and Class 2 of Grade LF2 deals with minimum Charpy impact energy requirements for the applicable test temperature (see Table 4 of ASME SA 350).

For Class 1 material, the minimum Charpy impact energy is 15 ft-lbs (for an average of 3 specimens) versus 20 ft-lbs (average of 3 specimens) for Class 2 material. The standard impact test temperature for Class 1 material is -50 deg F and for Class 2 is 0 deg F.

 

[kenvlach]

Operating temperature limits are specified according to use, e.g., by ASME for pressure vessels or API for oil pipeline, etc. ASTM A350/A350M-04a Standard Specification for Carbon and Low-Alloy Steel Forgings, Requiring Notch Toughness Testing for Piping Components details many test requirements, but the Charpy V-Notch test temperatures may answer your question. Per Table 5,
LF2 Class 1 is impact tested at -50^oF (-45.6^oC), and
LF2 Class 2 is tested at 0^oF (-18^oC).
Thus, forgings passing Class 1 tests are more suitable for low temperatures. Note that adjustments in absorbed energy and in test temperature apply if necessary to use reduced size impact specimens (smaller than 10x10 mm). Variations from specified test temperature must be noted.

ASTM A350/A350M-04a is a rather long, specification with many detailed requirements. A user would certainly be interested in those relating to workmanship, depth of imperfections, limits on repairs by welding,and product marking, to name just a few. In addition, changes were made in 2004 of which I am unaware. Best that you buy it at

http://www.astm.org/cgi-bin/SoftCar...EDLINE_PAGES/A350A350M.htm?L+mystore+xwmz3989