Categories
- Pipe & Tube (18)
- Flange & Fitting (97)
- Fastener & Gasket (12)
- Valve & Pump (18)
- Base Material (10)
- Equipment (8)
- Application (29)
- Technical (109)
The ASTM A350 LF2 is a forged carbon/ low-alloy steel grade for forged flanges, forged fittings and valves intended primarily for low-temperature service and requiring notch toughness testing. There are two Classes for the LF2 steels: Class 1 and Class 2.
Element | Weight % |
---|---|
C | ≤ 0.30 |
Mn | 0.60~1.35 |
P | ≤ 0.035 |
S | ≤ 0.040 |
Si | 0.15~0.30 |
Ni | ≤ 0.40 |
Cr | ≤ 0.30 |
Mo | ≤ 0.12 |
Cu | ≤ 0.40 |
Nb | ≤ 0.02 |
V | ≤ 0.08 |
N | - |
Item | Value |
---|---|
Tensile Strength, ksi [MPa] | 70-95 [485–655] |
Yield strength, ksi [MPa], min. | 36 [250] |
ELr, min. % | 22 |
ELs, min. % | 30 |
ELc, min. % | 48t + 15 |
Reduction of Area, min. % | 30 |
Hardness, max. HBW | 197 |
Since the ASTM A350 LF2 forgings are primarily used for low-temperature services, Charpy V-notch impact test is required to determine the notch toughness of the work piece. The Charpy V-notch impact test shall be conducted in accordance with ASTM A370 or ASTM A1058. Standard test specimens shall be prepared first, the cross section of which shall be 10 mm x 10 mm. Three pieces of test specimens of each heat lot shall be prepared. Generally, the minimum applicable temperature for Class 1 of ASTM A350 LF2 is -46°C [-50°F], while it is 0°C [-18°F] for Class 2 of ASTM A350 LF2. The minimum applicable temperatures are also the standard impact test temperatures for standard-size specimens.
Grade & Class | Eav min. ft*lbf [J] | Eeamin. ft*lbf [J] |
---|---|---|
LF2 Class 1 | 15 [20] | 12 [16] |
LF2 Class 2 | 20 [27] | 15 [20] |
When sub-size specimens are used, the impact energy values obtained shall conform to Table-S below at energy values proportional to standard size. Intermediate values can be obtained by straight-line interpolation.
Standard Size 10 x 10 mm | 3/4 Size 10 x 7.5 mm | 2/3 Size 10 x 6.6 mm |
15 [20] | 12 [16] | 10 [14] |
13 [18] | 10 [14] | 9 [12] |
12 [16] | 10 [14] | 9 [12] |
10 [14] | 8 [11] | 7 [10] |
1/2 Size 10 x 5 mm | 1/3 Size 10 x 3.3 mm | 1/4 Size 10 x 2.5 mm |
8 [11] | 5 [7] | 4 [6] |
7 [10] | 5 [7] | 4 [6] |
7 [10] | 4 [6] | 3 [5] |
5 [7] | 3 [5] | 3 [5] |