Steel 45L-N (Normalized)
Heat-treated state
GOST 45L
Refines the cast structure and gives balanced strength; the minimum treatment for load-bearing 45Л castings.
Values for the N condition
Other 45L tempers and conditions
45L is listed in 6 conditions; see the grade overview at 45L.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Untreated casting, used only for low-stress or later heat-treated parts; coarse dendritic structure, low ductility. | 290 | 540 | 8 | 190 HB | 8.5 % IACS |
Solution annealed | Choose for maximum machinability and stress relief before further machining or welding. | 290 | 550 | 15 | 179 HB | 8.7 % IACS |
NThis page Normalized | Refines the cast structure and gives balanced strength; the minimum treatment for load-bearing 45Л castings. | 320 | 590 | 11 | 207 HB | 8.5 % IACS |
N+TDefault Normalized and tempered | Standard supply condition of ГОСТ 977 45Л castings: good strength with restored toughness and dimensional stability. | 330 | 600 | 12 | 207 HB | 8.5 % IACS |
Normalized/Q&T core with induction- or flame-hardened surface | Use for cast sprockets, rollers and gear teeth needing a wear-resistant 45–52 HRC skin on a tough core. | 340 | 620 | 10 | 48 HRC | 8 % IACS |
Quenched and tempered | Pick when higher yield strength and fatigue capacity are needed in gears, sprockets and heavily loaded links; limited to moderate section sizes. | 460 | 720 | 10 | 23 HRC | — |
What is 45L-N?
45L-N is 45L heat treated to N — refines the cast structure and gives balanced strength; the minimum treatment for load-bearing 45Л castings. 45L-N has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 590 MPa (85.6 ksi) — weaker than 81% of steel grades. Elongation at break is 11% and the elastic modulus is 205 GPa (29.7 Msi). 45L-N has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F). N+T is the default condition FabDigit quotes; N is available on request or by drawing note.
Advantages
- Conducts heat well — 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades
Limitations
- Limited formability — 14/100, worse than 90% of steel grades
- Limited ductility — 11%, worse than 89% of steel grades
- Low fracture toughness — 48 MPa·√m (43.7 ksi·√in), worse than 88% of steel grades
- Low strength — 320 MPa (46.4 ksi), worse than 81% of steel grades
45L-N properties
Typical room-temperature values for 45L-N; 22 are specific to this condition. Other listed values are 45L reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
45L-N has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
45L-N has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 590 MPa (85.6 ksi) — weaker than 81% of steel grades. Elongation at break is 11% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
45L-N is rated for continuous service to 400°C (752 °F). It conducts heat at 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
45L-N conducts electricity at 8.5 % IACS, better than 63% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of 45L-N takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 80%.
Manufacturability7
45L-N's machinability is fair (52/100, better than 52% of steel grades); weldability poor (30/100); formability not recommended (14/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 45L-N
Is 45L easy to machine?
Machine in the annealed or N+T condition with carbide tooling; expect abrasive scale and possible hard spots at chill zones — remove the cast skin in the first cut.
Can 45L be welded?
Poor weldability at 0.45 %C: use low-hydrogen electrodes, 200–300 °C preheat/interpass, and 600–650 °C post-weld tempering to avoid cracking.
Can 45L be formed, bent or molded?
Sand or investment cast; needs generous risering and directional solidification to avoid shrinkage porosity, plus a full normalize to break up the dendritic structure.
What surface finishes work on 45L?
Shot blast then paint, phosphate or zinc-rich primer; hard chrome or induction-hardened and ground bearing surfaces where wear matters.
45L 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 |
|---|---|---|
| C | 0.42 – 0.5 | 0.45 |
| Si | 0.2 – 0.52 | 0.35 |
| Mn | 0.4 – 0.9 | 0.65 |
| Crresidual | ≤ 0.3 | 0.1 |
| Niresidual | ≤ 0.3 | 0.1 |
| Curesidual | ≤ 0.3 | 0.1 |
| S0.06 max for lower casting groups | ≤ 0.05 | 0.03 |
| P0.06 max for lower casting groups | ≤ 0.04 | 0.03 |
| Fe | balance | — |
45L-N — frequently asked
What is 45L-N used for?
45L-N is typically used for heavy gears, wear parts, crusher components and large machine housings. In short: high-strength cast carbon steel; wear-resistant as-cast parts; poor weldability, machine annealed.
What is the yield strength of 45L-N?
45L-N has a typical yield strength of 320 MPa (46.4 ksi) and a tensile strength of 590 MPa (85.6 ksi) — weaker than 81% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 45L-N easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machine in the annealed or N+T condition with carbide tooling; expect abrasive scale and possible hard spots at chill zones — remove the cast skin in the first cut.
Can 45L-N be welded?
Not readily — weldability is rated poor (30/100). Poor weldability at 0.45 %C: use low-hydrogen electrodes, 200–300 °C preheat/interpass, and 600–650 °C post-weld tempering to avoid cracking.
What surface finishes work on 45L-N?
Shot blast then paint, phosphate or zinc-rich primer; hard chrome or induction-hardened and ground bearing surfaces where wear matters.
Can 45L-N be formed, bent or molded?
Sand or investment cast; needs generous risering and directional solidification to avoid shrinkage porosity, plus a full normalize to break up the dendritic structure.
What is the maximum service temperature of 45L-N?
45L-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 45L N+T and 45L-F?
N+T is the default condition — standard supply condition of ГОСТ 977 45Л castings: good strength with restored toughness and dimensional stability. F: untreated casting, used only for low-stress or later heat-treated parts; coarse dendritic structure, low ductility. Yield strength is 330 MPa in N+T versus 290 MPa in F.
Sources
- ГОСТ 977-88 Отливки стальные. Общие технические условия — Госстандарт СССР (1988)
- Марочник сталей и сплавов — Машиностроение (Сорокин В.Г.) (2003)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels and High-Performance Alloys (cast carbon steels) — ASM International (1990)
- GB/T 11352 (ZG270-500 comparison) — SAC (2009)
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.