ASTM A350 / A350M Grade LF787 Class 2

ASTM A350 Grade LF787 Class 2 is a standard material specification for carbon and low alloy steel forgings, requiring notch toughness testing for piping components. This includes forged flanges, fittings, valves and similar forged and machined parts. This specification covers requirements such as chemical composition, mechanical properties and impact test for notch toughness. Ferrobend stocks, manufactures and supplies forgings, flanges, pipe fittings, valves and similar piping components in ASTM A350 Grade LF787 Class 2 specification.

Chemical Composition

Element	Composition
Carbon, max	0.07
Manganese	0.40–0.70
Phosphorus, max	0.025
Sulfur, max	0.025
Silicon [Note A]	0.40 max
Nickel	0.70–1.00
Chromium	0.60–0.90
Molybdenum	0.15–0.25
Copper	1.00–1.30
Columbium	0.02 min
Vanadium	0.03 max

Note:
A: When vacuum carbon-deoxidation is required by Supplementary Requirement S4, the silicon content shall be 0.12 % maximum.
B:The sum of copper, nickel, chromium, vanadium and molybdenum shall not exceed 1.00 % on heat analysis.
C:The sum of chromium and molybdenum shall not exceed 0.32 % on heat analysis.
D:By agreement, the limit for columbium may be increased up to 0.05 % on heat analysis and 0.06 % on product analysis.

Heat Treatment

1: Grade LF787 forgings shall be furnished in either the normalized-and-precipitation heat treated condition or in the quenched-and-precipitation heat treated condition. The heat treatment procedures shall be as follows:
1.1:Normalized-and-Precipitation Heat Treated—Heat to a temperature in the range from 1600 to 1725 °F [870 to 940°C], hold at the temperature for a time sufficient to attain uniform temperature throughout, soak at the temperature for not less than 1⁄2 h, and remove from the furnace and cool in air. Subsequently, heat to a temperature in the range from 1000 to 1200 °F [540 to 650 °C], soak at the temperature for not less than 1⁄2 h, and cool at any convenient rate.
1.2:Quenched-and-Precipitation Heat Treated—Heat to a temperature in the range from 1600 to 1725 °F [870 to 940°C], hold at the temperature for a time sufficient to attain uniform temperature throughout, soak at the temperature for not less than 1⁄2 h and quench in a suitable liquid medium by immersion; reheat to a temperature in the range from 1000 to 1225 °F [540 to 665 °C], hold at the temperature for not less than 1⁄2 h, and cool at any convenient rate.

Mechanical Properties [Note A]

Tensile Strength, ksi [MPa]	Yield Strength, min, ksi [MPa] [Note B, C]	Elongation		Reduction of Area, min, %
		Round Specimen in 4D, min, %	Strip Specimen in 2 Inch [50mm], min, %
65–85 [450–585]	55 [380]	20	28	45

Notes:
A: See 7.3 for hardness tests.
B: Determined by either the 0.2 % offset method or the 0.5 % extension under load method.
C: For round specimens only.

Charpy V-Notch Energy Requirements [10mm by 10mm]

Minimum Impact Energy Required for Average of Each Set of Three Specimens, ft.lbf [J]	Minimum Impact Energy Permitted for One Specimen only of a Set, ft.lbf [J]	Testing Temperature, °F [°C]
15 [20]	12 [16]	−75 [−59]

Associate Standards