ASME B16.5 Welding Neck/Wnrf A350 Lf2/ SA350 Lf2 Flange
TianYuan(HK) International Limited
Shanghai, China
Last Login Date:
Jun 18, 2025
Main Products:
Forged Flange, ASME B16.5 B16.47A/B En1092-1 GOST DIN Flange, Carbon Steel Flange, Stainless Steel Flange, Copper Nickel Flange, ASTM A182 F304/L F316/L Flange, ASTM A105 A350lf2 A694 F65 F70 Flange, Welding Neck Flange, Blind Slip on Threaded Socket Weld Lap Joint
Product Description
Company Info
Basic Info.
Product Description
ASTM A350 is the standard specification covering carbon and low-alloy steel forged or ring-rolled flanges, forged fittings and valves intended primarily for low-temperature service and requiring notch toughness testing. They are manufactured to corresponding ASME or API dimensional standards. The forgings may be made from ingots, blooms, billets, slabs or bars through hot-forging process. The steel shall be fully killed and fine-grain. ASTM A350 covers several grades and classes: Grade LF1, Grade LF2, Grade LF3, Grade LF5, Grade LF6, Grade LF9, Grade LF787; and Class 1, Class 2, Class 3.
1. ASTM A350 Chemical Composition Requirements
| Element | Composition, w.t % Grades | ||||||
| LF1 | LF2 | LF3 | LF5 | LF6 | LF9 | LF787 | |
| C | ≤0.30 | ≤0.30 | ≤0.20 | ≤0.30 | ≤0.22 | ≤0.20 | ≤0.07 |
| Mn | 0.60-1.35 | 0.60-1.35 | ≤0.90 | 0.60-1.35 | 1.15-1.50 | 0.40-1.06 | 0.40-0.70 |
| P | ≤0.035 | ≤0.035 | ≤0.035 | ≤0.035 | ≤0.025 | ≤0.035 | ≤0.025 |
| S | ≤0.040 | ≤0.040 | ≤0.040 | ≤0.040 | ≤0.025 | ≤0.040 | ≤0.025 |
| Si | 0.15-0.30 | 0.15-0.30 | 0.20-0.35 | 0.20-0.35 | 0.15-0.30 | ... | ≤0.40 |
| Ni | ≤0.40 | ≤0.40 | 3.30-3.70 | 1.00-2.00 | ≤0.40 | 1.60-2.24 | 0.70-1.00 |
| Cr | ≤0.30 | ≤0.30 | ≤0.30 | ≤0.30 | ≤0.30 | ≤0.30 | 0.60-0.90 |
| Mo | ≤0.12 | ≤0.12 | ≤0.12 | ≤0.12 | ≤0.12 | ≤0.12 | 0.15-0.25 |
| Cu | ≤0.40 | ≤0.40 | ≤0.40 | ≤0.40 | ≤0.40 | 0.75-1.25 | 1.00-1.30 |
| Cb | ≤0.02 | ≤0.02 | ≤0.02 | ≤0.02 | ≤0.02 | ≤0.02 | ≥0.02 |
| V | ≤0.08 | ≤0.08 | ≤0.03 | ≤0.03 | 0.04-0.11 | ≤0.03 | ≤0.03 |
| N | ... | ... | ... | ... | 0.01-0.030 | ... | ... |
*2. For grades LF1, LF2 & LF6, the sum of Cu, Ni, Cr, V and Mo shall not exceed 1.00 % on heat analysis.
*3. For all grades except grade LF787, the sum of Cr and Mo shall not exceed 0.32 % on heat analysis.
*4. For grades LF1 & LF2, the limit for Cb may be increased up to 0.05 % on heat analysis and 0.06 % on product analysis.
*5. The carbon equivalent C.E = [C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15] shall not exceed 0.45%.
2. ASTM A350 Mechanical Properties
| Grade/Class | Tensile Strength | Yield Strength, min. | Elongation, min. | Hardness, max. | ||
| ksi | MPa | ksi | MPa | % | HBW | |
| LF1 CL1 | 60-85 | 415-585 | 30 | 205 | 25 | 197 |
| LF5 CL1 | 60-85 | 415-585 | 30 | 205 | 25 | 197 |
| LF2 CL1 | 70-95 | 485-655 | 36 | 250 | 22 | 197 |
| LF2 CL2 | 70-95 | 485-655 | 36 | 250 | 22 | 197 |
| LF3 CL1 | 70-95 | 485-655 | 37.5 | 260 | 22 | 197 |
| LF3 CL2 | 70-95 | 485-655 | 37.5 | 260 | 22 | 197 |
| LF5 CL2 | 70-95 | 485-655 | 37.5 | 260 | 22 | 197 |
| LF6 CL1 | 66-91 | 455-630 | 52 | 360 | 22 | 197 |
| LF6 CL2 | 75-100 | 515-690 | 60 | 415 | 20 | 197 |
| LF6 CL3 | 75-100 | 515-690 | 60 | 415 | 20 | 197 |
| LF9 | 63-88 | 435-605 | 46 | 315 | 25 | 197 |
| LF787 CL2 | 65-85 | 450-585 | 55 | 380 | 20 | 197 |
| LF787 CL3 | 75-95 | 515-655 | 65 | 450 | 20 | 197 |
*2. The yield strength shall be determined by either the 0.2 % offset method or the 0.5 % extension under load method.
3. ASTM A350 Charpy V-Notch Impact Properties
| Charpy V-Notch Energy Requirements for 10x10 mm Specimens | ||||
| Grade/ Class | *A | *B | ||
| ft*lbf | J | ft*lbf | J | |
| LF1 and LF9 | 13 | 18 | 10 | 14 |
| LF2 CL1 | 15 | 20 | 12 | 16 |
| LF3 CL1 | 15 | 20 | 12 | 16 |
| LF5 CL1 & CL2 | 15 | 20 | 12 | 16 |
| LF787 CL2 & CL3 | 15 | 20 | 12 | 16 |
| LF6 CL1 | 15 | 20 | 12 | 16 |
| LF2 CL2 | 20 | 27 | 15 | 20 |
| LF3 CL2 | 20 | 27 | 15 | 20 |
| LF6 CL2 & CL3 | 20 | 27 | 15 | 20 |
*B denotes minimum impact energy permitted for one specimen only of a set.
| Standard Impact Test Temperature for 10x10 mm Specimens | ||
| Grade/ Class | Test Temperature | |
| °F | °C | |
| LF1 | -20 | -29 |
| LF2 CL1 | -50 | -46 |
| LF2 CL2 | -0 | -18 |
| LF3 CL1 & CL2 | -150 | -101 |
| LF5 CL1 & CL2 | -75 | -59 |
| LF6 CL1 & CL2 | -60 | -51 |
| LF6 CL3 | -0 | -18 |
| LF9 | -100 | -73 |
| LF787 CL2 | -75 | -59 |
| LF787 CL3 | -100 | -73 |
| Minimum Equivalent Absorbed Energy for Various Specimen Sizes. ft·lbf [J] | |||||
| Standard Size | 3/4 Size | 2/3 Size | 1/2 Size | 1/3 Size | 1/4 Size |
| 10x10 mm | 10x7.5 mm | 10x6.6 mm | 10x5 mm | 10x3.3 mm | 10x2.5 mm |
| 15 [20] | 12 [16] | 10 [14] | 8 [11] | 5 [7] | 4 [6] |
| 13 [18] | 10 [14] | 9 [12] | 7 [10] | 5 [7] | 4 [6] |
| 12 [16] | 10 [14] | 9 [12] | 7 [10] | 4 [6] | 3 [5] |
| 10 [14] | 8 [11] | 7 [10] | 5 [7] | 3 [5] | 3 [5] |
* Straight-line interpolation for intermediate values is permitted.
4. Heat Treatment & Welding Process
As specified by ASTM A350, after hot working and before reheating for heat treatment, the forging shall be allowed to cool substantially below the transformation range. Forgings of grades other than Grade LF787 shall be furnished in the normalized, or normalized and tempered, or quenched and tempered condition. All quenched forgings shall be then tempered at 1100 °F [590 °C], minimum, holding at temperature a minimum of 30 min/in. [30 min/25 mm] of maximum thickness, but in no case less than 30 min. Grade LF787 forgings shall be furnished in either the normalized-and-precipitation heat treated condition or in the quenched-and-precipitation heat treated condition.
For Grade LF1 and LF2 forgings, the weld metal shall be deposited using carbon steel electrodes E 7015, E 7016, or E 7018, complying with AWS A 5.1. For Grade LF2 forgings, the weld metal shall be deposited using low-alloy steel electrodes E 7015-A1; E 7016-A1, or E 7018-A1 complying with AWS 5.5; for Grade LF3 forgings, the weld metal shall be deposited using low-alloy steel electrodes E 8016-C2 or E 8018-C2 complying with AWS A 5.5; for Grades LF5, LF9, and LF787 forgings, the weld metal shall be deposited using low-alloy steel electrodes E 8016-C1 or E 8018-C1 complying withAWS A 5.5. For Grade LF6, the electrodes shall be low-hydrogen, E-XX15, E-XX16, or E-XX18 complying with AWS A 5.1 or A 5.5, as applicable.
DN15-DN3000
Maximum weight 6tons
25,000tons production annual year
ANSI B16.5,ANSI B16.47 Series A&B,ANSI B16.48,ANSI B16.36
API 605,API 16D,API 17D
BS4504,BS3293
DIN
AS
EN1092-1
GOST
EEMUA145
EN10204-3.2 byTUV,BV,Lloyds,GL,DNV,SGS,ABS,RINA,Moody or other third parties
