Steel A182 FR-N (Normalized)
Heat-treated state
ASTM A182 FR · UNS K22035
Normalized-only forgings for thin sections where tempering is not required and moderate strength suffices.
Values for the N condition
Other A182 FR tempers and conditions
A182 FR is listed in 3 conditions; see the grade overview at A182 FR.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
NThis page Normalized | Normalized-only forgings for thin sections where tempering is not required and moderate strength suffices. | 330 | 505 | 27 | 150 HB | 7.5 % IACS |
N+TDefault Normalized and tempered | Standard mill-supplied condition for A182 FR flanges and fittings; best balance of strength and −46 °C notch toughness. | 355 | 520 | 26 | 160 HB | — |
Quenched and tempered | Choose for heavy-section forgings or when the highest low-temperature impact energy and through-thickness properties are needed. | 450 | 585 | 23 | 185 HB | — |
What is A182 FR-N?
A182 FR-N is A182 FR heat treated to N — normalized-only forgings for thin sections where tempering is not required and moderate strength suffices. A182 FR-N has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 505 MPa (73.2 ksi) — weaker than 78% of steel grades. Elongation at break is 27% and the elastic modulus is 205 GPa (29.7 Msi). A182 FR-N has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F). N+T is the default condition FabDigit quotes; N is available on request or by drawing note.
Advantages
- Good corrosion resistance — 22/100, better than 90% of steel grades
- Ductile — tolerates forming and impact — 27%, better than 86% of steel grades
Limitations
- Low strength — 330 MPa (47.9 ksi), worse than 78% of steel grades
A182 FR-N properties
Typical room-temperature values for A182 FR-N; 22 are specific to this condition. Other listed values are A182 FR reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A182 FR-N has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical15
A182 FR-N has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 505 MPa (73.2 ksi) — weaker than 78% of steel grades. Elongation at break is 27% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
A182 FR-N is rated for continuous service to 400°C (752 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 64% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
A182 FR-N conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (22/100), better than 90% of steel grades.
Sustainability4
Producing a kilogram of A182 FR-N takes about 26 MJ of energy and emits 2.1 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 30%.
Manufacturability7
A182 FR-N's machinability is good (60/100, better than 83% of steel grades); weldability good (66/100); formability fair (48/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A182 FR-N
Is A182 FR easy to machine?
Machines like normalized 4130/A350-class steel at ~60 % of AISI 1212; use rigid setups, carbide inserts and moderate speeds — copper content can cause slight gumminess in soft condition.
Can A182 FR be welded?
Weldable with low-hydrogen SMAW/GTAW/SAW using matching or 1–2 %Ni filler; preheat 100–150 °C, control interpass, and PWHT/temper at ~595–650 °C to restore −46 °C notch toughness.
Can A182 FR be formed, bent or molded?
Hot forge at 1050–1200 °C with finishing above 900 °C, then normalize (or quench) and temper; cold forming is limited and should be followed by stress relief.
What surface finishes work on A182 FR?
Not anodizable — protect with shop primer, epoxy/zinc-rich paint, hot-dip galvanizing or electroless nickel; bare surfaces will form a weathering patina outdoors.
A182 FR chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cmax per ASTM A182 Grade FR | ≤ 0.2 | 0.15 |
| Mn | 0.4 – 1.06 | 0.8 |
| Si | 0.15 – 0.3 | 0.22 |
| Pimpurity limit | ≤ 0.05 | 0.02 |
| Simpurity limit | ≤ 0.05 | 0.01 |
| Niprovides low-temperature toughness | 1.6 – 2.24 | 1.9 |
| Cr | 0.7 – 1.1 | 0.9 |
| Cuatmospheric corrosion resistance | 0.75 – 1.25 | 1 |
| Fe | balance | — |
A182 FR-N — frequently asked
What is A182 FR-N used for?
A182 FR-N is typically used for LNG piping flanges, low-temperature valve bodies and cold-service fittings. In short: cryogenic-toughness nickel forging; best weldability in family; qualified at −46 °C.
What is the yield strength of A182 FR-N?
A182 FR-N has a typical yield strength of 330 MPa (47.9 ksi) and a tensile strength of 505 MPa (73.2 ksi) — weaker than 78% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is A182 FR-N easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machines like normalized 4130/A350-class steel at ~60 % of AISI 1212; use rigid setups, carbide inserts and moderate speeds — copper content can cause slight gumminess in soft condition.
Can A182 FR-N be welded?
Yes — weldability is rated good (66/100). Weldable with low-hydrogen SMAW/GTAW/SAW using matching or 1–2 %Ni filler; preheat 100–150 °C, control interpass, and PWHT/temper at ~595–650 °C to restore −46 °C notch toughness.
What surface finishes work on A182 FR-N?
Not anodizable — protect with shop primer, epoxy/zinc-rich paint, hot-dip galvanizing or electroless nickel; bare surfaces will form a weathering patina outdoors.
Can A182 FR-N be formed, bent or molded?
Hot forge at 1050–1200 °C with finishing above 900 °C, then normalize (or quench) and temper; cold forming is limited and should be followed by stress relief.
What is the maximum service temperature of A182 FR-N?
A182 FR-N is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A182 FR N+T and A182 FR-N?
N+T is the default condition — standard mill-supplied condition for A182 FR flanges and fittings; best balance of strength and −46 °C notch toughness. N: normalized-only forgings for thin sections where tempering is not required and moderate strength suffices. Yield strength is 355 MPa in N+T versus 330 MPa in N.
Sources
- ASTM A182/A182M — Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts — ASTM International (2023)
- ASTM A350/A350M — Carbon and Low-Alloy Steel Forgings Requiring Notch Toughness Testing (Grade LF9 comparison) — ASTM International (2022)
- ASME BPVC Section II Part D — Physical and allowable stress data for low-alloy steels — ASME (2023)
- ASME B16.5 / B16.34 — Pipe Flanges and Valve Material Groups — ASME (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13A — Corrosion: Fundamentals, Testing, and Protection (weathering steels) — ASM International (2003)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.