Steel A352 Grade LC2 NN+T
Heat-treated state
ASTM A352 Grade LC2 · UNS J22500
NN+T = double normalized and tempered
Used on large or heavily fed castings to refine grain after weld repair and secure repeatable -73 °C impact values.
Values for the NN+T condition
Other A352 Grade LC2 tempers and conditions
A352 Grade LC2 is listed in 3 conditions; see the grade overview at A352 Grade LC2.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
N+TDefault Normalized and tempered | Standard supply condition for most LC2 valve bodies and fittings; adequate -73 °C toughness with good section-size tolerance. | 340 | 530 | 28 | 160 HB | — |
NN+TThis page Double normalized and tempered | Used on large or heavily fed castings to refine grain after weld repair and secure repeatable -73 °C impact values. | 350 | 535 | 29 | 163 HB | 8 % IACS |
Quenched and tempered | Choose for heavier sections or where higher strength and upper-shelf toughness margin at -73 °C are wanted. | 400 | 580 | 26 | 180 HB | — |
What is A352 Grade LC2 NN+T?
A352 Grade LC2 NN+T is A352 Grade LC2 heat treated to NN+T — used on large or heavily fed castings to refine grain after weld repair and secure repeatable -73 °C impact values. A352 Grade LC2 NN+T has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 535 MPa (77.6 ksi) — weaker than 74% of steel grades. Elongation at break is 29% and the elastic modulus is 200 GPa (29 Msi). A352 Grade LC2 NN+T has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). N+T is the default condition FabDigit quotes; NN+T is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 29%, better than 91% of steel grades
- Tough — resists crack growth — 125 MPa·√m (113.8 ksi·√in), better than 85% of steel grades
Limitations
- Limited formability — 10/100, worse than 95% of steel grades
A352 Grade LC2 NN+T properties
Typical room-temperature values for A352 Grade LC2 NN+T; 23 are specific to this condition. Other listed values are A352 Grade LC2 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A352 Grade LC2 NN+T has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical15
A352 Grade LC2 NN+T has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 535 MPa (77.6 ksi) — weaker than 74% of steel grades. Elongation at break is 29% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
A352 Grade LC2 NN+T is rated for continuous service to 400°C (752 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 69% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
A352 Grade LC2 NN+T conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of A352 Grade LC2 NN+T takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 75%.
Manufacturability7
A352 Grade LC2 NN+T's machinability is fair (50/100, worse than 53% of steel grades); weldability good (65/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A352 Grade LC2 NN+T
Is A352 Grade LC2 easy to machine?
Machines like normalized low-alloy steel at ~55–60 % of 1212; use rigid setups and watch for hard spots or sand inclusions at the as-cast skin.
Can A352 Grade LC2 be welded?
Readily welded with matching 2.5Ni or Ni-bearing low-hydrogen consumables; preheat 100–150 °C, control interpass, and PWHT/temper at ≥593 °C to restore low-temperature toughness.
Can A352 Grade LC2 be formed, bent or molded?
Supplied as sand or investment castings; provide generous fillets and chills at section changes to avoid shrinkage porosity in pressure-boundary walls.
What surface finishes work on A352 Grade LC2?
No anodizing; protect with shot blast plus epoxy/zinc-rich paint, galvanizing or ENP — bare surfaces rust rapidly in humid and marine service.
A352 Grade LC2 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 A352 | ≤ 0.25 | 0.2 |
| Mn | 0.5 – 0.8 | 0.65 |
| Si | ≤ 0.6 | 0.4 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.05 | 0.02 |
| Ninominal 2-1/2 % Ni grade | 2 – 3 | 2.5 |
| Crresidual | ≤ 0.5 | 0.1 |
| Moresidual | ≤ 0.2 | 0.05 |
| Curesidual | ≤ 0.5 | 0.15 |
| Vresidual; total residuals ≤ 1.00 % | ≤ 0.03 | 0.01 |
| Fe | balance | — |
A352 Grade LC2 NN+T — frequently asked
What is A352 Grade LC2 NN+T used for?
A352 Grade LC2 NN+T is typically used for cryogenic valve bodies, low-temperature pump casings and LNG facility fittings. In short: 3-1/2% Ni cryogenic casting; tough to about -100 °F; weldable pressure-grade casting.
What is the yield strength of A352 Grade LC2 NN+T?
A352 Grade LC2 NN+T has a typical yield strength of 350 MPa (50.8 ksi) and a tensile strength of 535 MPa (77.6 ksi) — weaker than 74% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is A352 Grade LC2 NN+T easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machines like normalized low-alloy steel at ~55–60 % of 1212; use rigid setups and watch for hard spots or sand inclusions at the as-cast skin.
Can A352 Grade LC2 NN+T be welded?
Yes — weldability is rated good (65/100). Readily welded with matching 2.5Ni or Ni-bearing low-hydrogen consumables; preheat 100–150 °C, control interpass, and PWHT/temper at ≥593 °C to restore low-temperature toughness.
What surface finishes work on A352 Grade LC2 NN+T?
No anodizing; protect with shot blast plus epoxy/zinc-rich paint, galvanizing or ENP — bare surfaces rust rapidly in humid and marine service.
Can A352 Grade LC2 NN+T be formed, bent or molded?
Supplied as sand or investment castings; provide generous fillets and chills at section changes to avoid shrinkage porosity in pressure-boundary walls.
What is the maximum service temperature of A352 Grade LC2 NN+T?
A352 Grade LC2 NN+T 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.
Sources
- ASTM A352/A352M — Steel Castings, Ferritic and Martensitic, for Pressure-Containing Parts, Suitable for Low-Temperature Service — ASTM International (2023)
- ASME BPVC Section II Part D — Materials, Properties — ASME (2023)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Steel Castings Handbook, 6th ed. — Steel Founders' Society of America / ASM (1995)
- UNS J22500 alloy record — SAE/ASTM Unified Numbering System (2022)
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.