Steel A352 Grade LC4 Q+T
Heat-treated state
ASTM A352 Grade LC4 · UNS J41500
Q+T = quenched and tempered
Chosen for heavy-section castings where quenching restores uniform low-temperature impact energy and higher yield strength.
Values for the Q+T condition
Other A352 Grade LC4 tempers and conditions
A352 Grade LC4 is listed in 4 conditions; see the grade overview at A352 Grade LC4.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Normalized, tempered and post-weld stress relieved | Condition after weld repair or fabrication welding; stress relief below the tempering temperature preserves cryogenic toughness. | 320 | 525 | 30 | 165 HB | 4.9 % IACS |
N+TDefault Normalized and tempered | Standard supply condition for LC4 valve and pump castings; best balance of -115 °C toughness, ductility and cost. | 330 | 540 | 30 | 170 HB | — |
Double normalized and tempered | Specified when extra grain refinement is needed to pass -115 °C Charpy in thick or weld-repaired castings. | 345 | 550 | 31 | 172 HB | 4.9 % IACS |
Q+TThis page Quenched and tempered | Chosen for heavy-section castings where quenching restores uniform low-temperature impact energy and higher yield strength. | 380 | 585 | 28 | 185 HB | 4.9 % IACS |
What is A352 Grade LC4 Q+T?
A352 Grade LC4 Q+T is A352 Grade LC4 heat treated to Q+T — chosen for heavy-section castings where quenching restores uniform low-temperature impact energy and higher yield strength. A352 Grade LC4 Q+T has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 68% of steel grades. Elongation at break is 28% and the elastic modulus is 200 GPa (29 Msi). A352 Grade LC4 Q+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; Q+T is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 165 MPa·√m (150.2 ksi·√in), better than 98% of steel grades
- Ductile — tolerates forming and impact — 28%, better than 89% of steel grades
Limitations
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
- Limited formability — 18/100, worse than 84% of steel grades
- Poor heat conductor — 32 W/m·K (18.5 BTU/hr·ft·°F), worse than 82% of steel grades
A352 Grade LC4 Q+T properties
Typical room-temperature values for A352 Grade LC4 Q+T; 23 are specific to this condition. Other listed values are A352 Grade LC4 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A352 Grade LC4 Q+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 LC4 Q+T has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 68% of steel grades. Elongation at break is 28% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
A352 Grade LC4 Q+T is rated for continuous service to 340°C (644 °F). It conducts heat at 32 W/m·K (18.5 BTU/hr·ft·°F), worse than 82% of steel grades. Thermal expansion is 11.3 µm/m·K (6.28 µin/in·°F).
Electrical2
A352 Grade LC4 Q+T has an electrical resistivity of 3.5×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of A352 Grade LC4 Q+T takes about 33 MJ of energy and emits 2.6 kg of CO₂ — more than 76% of steel grades. Typical recycled content is 75%.
Manufacturability7
A352 Grade LC4 Q+T's machinability is fair (52/100, better than 52% of steel grades); weldability good (58/100); formability poor (18/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A352 Grade LC4 Q+T
Is A352 Grade LC4 easy to machine?
Machines like a 4-5% Ni low-alloy steel at ~60% of 1212; use rigid setups, sharp carbide and moderate speeds because the tough austenitizing-free matrix work-hardens and gums at low feeds.
Can A352 Grade LC4 be welded?
Weldable with low-hydrogen SMAW/GTAW using nickel-alloy or matching consumables, 100–150 °C preheat, controlled interpass and PWHT below the tempering temperature to protect -115 °C impact values.
Can A352 Grade LC4 be formed, bent or molded?
Sand-cast with generous risering and controlled pouring temperature; gray-to-fine microstructure requires normalizing to break up as-cast dendritic structure before impact testing.
What surface finishes work on A352 Grade LC4?
No inherent corrosion resistance — shot blast and apply epoxy/zinc-rich primer or insulate; can be electroless nickel or hard-chrome plated on seating surfaces.
A352 Grade LC4 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 | ≤ 0.15 | 0.1 |
| Mn | ≤ 0.5 | 0.4 |
| Si | ≤ 0.6 | 0.4 |
| P | ≤ 0.04 | — |
| S | ≤ 0.05 | — |
| Niprincipal cryogenic toughness addition | 4 – 5 | 4.5 |
| Fe | balance | — |
A352 Grade LC4 Q+T — frequently asked
What is A352 Grade LC4 Q+T used for?
A352 Grade LC4 Q+T is typically used for cryogenic vessel fittings, low-temperature valve bodies, LNG and ethane plant piping components, refrigerated pump and compressor casings, cold-service flanges and bonnets and air-separation plant pressure fittings. In short: 4-1/2% Ni cryogenic casting; tough to about -115 °C; between LC3 and LC9.
What is the yield strength of A352 Grade LC4 Q+T?
A352 Grade LC4 Q+T has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 68% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is A352 Grade LC4 Q+T easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machines like a 4-5% Ni low-alloy steel at ~60% of 1212; use rigid setups, sharp carbide and moderate speeds because the tough austenitizing-free matrix work-hardens and gums at low feeds.
Can A352 Grade LC4 Q+T be welded?
Yes — weldability is rated good (58/100). Weldable with low-hydrogen SMAW/GTAW using nickel-alloy or matching consumables, 100–150 °C preheat, controlled interpass and PWHT below the tempering temperature to protect -115 °C impact values.
What surface finishes work on A352 Grade LC4 Q+T?
No inherent corrosion resistance — shot blast and apply epoxy/zinc-rich primer or insulate; can be electroless nickel or hard-chrome plated on seating surfaces.
Can A352 Grade LC4 Q+T be formed, bent or molded?
Sand-cast with generous risering and controlled pouring temperature; gray-to-fine microstructure requires normalizing to break up as-cast dendritic structure before impact testing.
What is the maximum service temperature of A352 Grade LC4 Q+T?
A352 Grade LC4 Q+T is rated for continuous use to about 340°C (644 °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 (2018)
- ASME BPVC Section II Part D — Material 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)
- ASME B31.3 Process Piping — Low Temperature Material Requirements — ASME (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.