Steel 18Ni(200) Maraging Steel Aged
Heat-treated state · default condition
UNS K92810, K92890 · AISI/SAE 18Ni200 · ASTM A538 Grade A · EN 1.6354 · also Vascomax C200
Aged = solution annealed + 480 °C/3 h age
Final service condition: ~1400 MPa yield with high toughness and near-zero aging distortion — machine in the annealed state, then age.
Values for the Aged condition
Other 18Ni(200) Maraging Steel tempers and conditions
18Ni(200) Maraging Steel is listed in 5 conditions; see the grade overview at 18Ni(200) Maraging Steel.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Supply/working condition: soft low-carbon nickel martensite for machining, bending and welding before the aging cycle. | 830 | 1,000 | 18 | 30 HRC | 25 W/m·K |
Annealed + cold drawn bar | Cold-drawn bar stock for tight tolerance and better surface before aging; the cold work also raises the final aged strength slightly. | 980 | 1,120 | 12 | 34 HRC | 3.4 % IACS |
As welded + post-weld aged | Weldment condition: matching filler, no preheat, single post-weld age restores about 85–95 % of parent aged strength. | 1,250 | 1,330 | 8 | 41 HRC | 3.8 % IACS |
AgedDefaultThis page Solution annealed + 480 °C/3 h age | Final service condition: ~1400 MPa yield with high toughness and near-zero aging distortion — machine in the annealed state, then age. | 1,400 | 1,450 | 12 | 43 HRC | 21 W/m·K |
Cold worked then aged | Use when maximum strength is wanted from Grade 200 (wire, thin strip); cold work before aging adds roughly 50–150 MPa at some ductility cost. | 1,500 | 1,560 | 8 | 46 HRC | — |
What is 18Ni(200) Maraging Steel Aged?
18Ni(200) Maraging Steel Aged is 18Ni(200) Maraging Steel heat treated to Aged — final service condition: ~1400 MPa yield with high toughness and near-zero aging distortion — machine in the annealed state, then age. 18Ni(200) Maraging Steel Aged has a yield strength of 1,400 MPa (203 ksi) and a tensile strength of 1,450 MPa (210 ksi) — stronger than 96% of steel grades. Elongation at break is 12% and the elastic modulus is 186 GPa (27 Msi). 18Ni(200) Maraging Steel Aged has a density of 8 g/cm³ (0.289 lb/in³), heavier than 95% of steel grades. It melts at 1,413°C (2,575 °F).
Advantages
- Tough — resists crack growth — 155 MPa·√m (141.1 ksi·√in), better than 97% of steel grades
- Polishes to a fine finish — 80/100, better than 97% of steel grades
- High strength — 1,400 MPa (203 ksi), better than 96% of steel grades
- Good corrosion resistance — 25/100, better than 92% of steel grades
Limitations
- High embodied carbon — 7.5 kg CO₂/kg, worse than 99% of steel grades
- Poor heat conductor — 20.5 W/m·K (11.8 BTU/hr·ft·°F), worse than 95% of steel grades
- Difficult to machine — 30/100, worse than 89% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
18Ni(200) Maraging Steel Aged properties
Typical room-temperature values for 18Ni(200) Maraging Steel Aged; 21 are specific to this condition. Other listed values are 18Ni(200) Maraging Steel reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
18Ni(200) Maraging Steel Aged has a density of 8 g/cm³ (0.289 lb/in³), heavier than 95% of steel grades. It melts at 1,413°C (2,575 °F).
Mechanical16
18Ni(200) Maraging Steel Aged has a yield strength of 1,400 MPa (203 ksi) and a tensile strength of 1,450 MPa (210 ksi) — stronger than 96% of steel grades. Elongation at break is 12% and the elastic modulus is 186 GPa (27 Msi).
Thermal6
18Ni(200) Maraging Steel Aged is rated for continuous service to 400°C (752 °F). It conducts heat at 20.5 W/m·K (11.8 BTU/hr·ft·°F), worse than 95% of steel grades. Thermal expansion is 10.1 µm/m·K (5.61 µin/in·°F).
Electrical3
18Ni(200) Maraging Steel Aged conducts electricity at 3.8 % IACS, worse than 84% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (25/100), better than 92% of steel grades.
Sustainability4
Producing a kilogram of 18Ni(200) Maraging Steel Aged takes about 110 MJ of energy and emits 7.5 kg of CO₂ — more than 99% of steel grades. Typical recycled content is 30%.
Manufacturability7
18Ni(200) Maraging Steel Aged's machinability is poor (30/100, worse than 89% of steel grades); weldability very good (70/100); formability poor (15/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 18Ni(200) Maraging Steel Aged
Is 18Ni(200) Maraging Steel easy to machine?
Machine in the annealed condition with sharp carbide tooling, rigid setups, positive rake and flood coolant; work-hardens and is gummy — expect ~50 % of 4340 annealed feed rates, and only finish-grind/EDM after aging.
Can 18Ni(200) Maraging Steel be welded?
Excellent weldability with matching maraging filler by GTAW/EBW/laser — no preheat, low heat input, clean joint prep, then a single 480 °C/3–6 h post-weld age to restore strength.
Can 18Ni(200) Maraging Steel be formed, bent or molded?
Form, bend, deep draw or roll in the soft annealed state (18 % elongation); aging causes only ~0.05 % linear shrinkage so tight-tolerance parts can be finished before hardening.
What surface finishes work on 18Ni(200) Maraging Steel?
Takes a mirror polish (VIM/VAR clean steel) and is nitrided for wear; not corrosion resistant, so use passivation plus cadmium/electroless-nickel plating or paint, and bake after plating to avoid hydrogen embrittlement.
18Ni(200) Maraging Steel 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 |
|---|---|---|
| Ni | 17 – 19 | 18 |
| Co | 8 – 9 | 8.5 |
| Mo | 3 – 3.5 | 3.3 |
| Tiprincipal aging element for the 200 grade | 0.15 – 0.25 | 0.2 |
| Al | 0.05 – 0.15 | 0.1 |
| Ckept low to avoid TiC | ≤ 0.03 | 0.02 |
| Si | ≤ 0.1 | 0.05 |
| Mn | ≤ 0.1 | 0.05 |
| P | ≤ 0.01 | 0.01 |
| S | ≤ 0.01 | 0.01 |
| Febalance, ~69 % | balance | — |
18Ni(200) Maraging Steel Aged — frequently asked
What is 18Ni(200) Maraging Steel Aged used for?
18Ni(200) Maraging Steel Aged is typically used for rocket motor cases, landing gear components and high-toughness structural fittings. In short: toughest 18Ni maraging grade; 0.05 % growth on aging; weldable ultra-high-strength steel.
What is the yield strength of 18Ni(200) Maraging Steel Aged?
18Ni(200) Maraging Steel Aged has a typical yield strength of 1,400 MPa (203 ksi) and a tensile strength of 1,450 MPa (210 ksi) — stronger than 96% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is 18Ni(200) Maraging Steel Aged easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Machine in the annealed condition with sharp carbide tooling, rigid setups, positive rake and flood coolant; work-hardens and is gummy — expect ~50 % of 4340 annealed feed rates, and only finish-grind/EDM after aging.
Can 18Ni(200) Maraging Steel Aged be welded?
Yes — weldability is rated very good (70/100). Excellent weldability with matching maraging filler by GTAW/EBW/laser — no preheat, low heat input, clean joint prep, then a single 480 °C/3–6 h post-weld age to restore strength.
What surface finishes work on 18Ni(200) Maraging Steel Aged?
Takes a mirror polish (VIM/VAR clean steel) and is nitrided for wear; not corrosion resistant, so use passivation plus cadmium/electroless-nickel plating or paint, and bake after plating to avoid hydrogen embrittlement.
Can 18Ni(200) Maraging Steel Aged be formed, bent or molded?
Form, bend, deep draw or roll in the soft annealed state (18 % elongation); aging causes only ~0.05 % linear shrinkage so tight-tolerance parts can be finished before hardening.
What is the maximum service temperature of 18Ni(200) Maraging Steel Aged?
18Ni(200) Maraging Steel Aged 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 18Ni(200) Maraging Steel Aged and 18Ni(200) Maraging Steel-ANN?
Aged is the default condition — final service condition: ~1400 MPa yield with high toughness and near-zero aging distortion — machine in the annealed state, then age. ANN: supply/working condition: soft low-carbon nickel martensite for machining, bending and welding before the aging cycle. Yield strength is 1,400 MPa in Aged versus 830 MPa in ANN.
Sources
- ASTM A538/A538M — Pressure Vessel Plates, Alloy Steel, Precipitation Hardening (Maraging), Grade A — ASTM International (2019)
- AMS 6520 / MIL-S-46850 — 18Ni maraging steel bar and plate — SAE International (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Maraging Steels) — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- VascoMax C-200 maraging steel technical data — Carpenter Technology / Latrobe Specialty Metals (2020)
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.