Low-Temp Flanges (ASTM A350)
A350 – This specification covers several grades of carbon and low alloy steel forged or ring-rolled flanges (LF2 in low-temp applications).
Chemical Composition
Element | Grade LF1 | Grade LF2 | Grade LF3 | Grade LF5 | Grade LF6 | Grade LF9 | Grade LF787 |
Carbon, max | 0.30 | 0.30 | 0.20 | 0.30 | 0.22 | 0.20 | 0.07 |
Manganese | 0.60-1.35 | 0.60-1.36 | 0.90 max | 0.60-1.35 | 1.15-1.50 | 0.40-1.06 | 0.40-0.70 |
Phosphorus, max | 0.035 | 0.035 | 0.035 | 0.035 | 0.025 | 0.035 | 0.025 |
Sulfur, max | 0.040 | 0.040 | 0.040 | 0.040 | 0.025 | 0.040 | 0.025 |
SiliconA | 0.15-0.30 | 0.15-0.30 | 0.20-0.35 | 0.20-0.35 | 0.15-0.30 | …. | 0.40-max |
Nickel | 0.40 maxB | 0.40 maxB | 3.3-3.7 | 1.0-2.0 | 0.40 maxB | 1.60-2.24 | 0.70-1.00 |
Chromium | 0.30 maxb,c | 0.30 maxb,c | 0.30 maxc | 0.30 maxc | 0.30 maxb,c | 0.30 maxc | 0.60-0.90 |
Molybdenum | 0.12 maxb,c | 0.12 maxb,c | 0.30 maxc | 0.12 maxc | 0.12 maxb,c | 0.12 maxc | 0.15-0.25 |
Copper | 0.40 maxB | 0.40 maxB | 0.40 max | 0.40 max | 0.40 maxB | 0.75-1.25 | 1.00-1.30 |
Columbium | 0.02 maxD | 0.02 maxD | 0.02 max | 0.02 max | 0.02 max | 0.02 max | 0.02 min |
Vanadium | 0.08 max | 0.08 max | 0.03 max | 0.03 max | 0.04-0.11 | 0.03 max | 0.03 max |
Nitrogen | …. | …. | …. | …. | 0.01-0.030 | …. | …. |