Steel 18Ni(190) Aged
Heat-treated state · default condition
also T-190, VascoMax 190
Aged = solution annealed + aged 480 °C / 3–6 h, air cool
Standard delivered-strength condition: ~190 ksi UTS with the best toughness of the 18 % Ni maraging series and almost no distortion during aging.
Values for the Aged condition
Other 18Ni(190) tempers and conditions
18Ni(190) is listed in 6 conditions; see the grade overview at 18Ni(190).
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Soft, tough nickel-martensite as supplied for machining, forming and welding before aging. | 800 | 1,000 | 18 | 29 HRC | 2.9 % IACS |
As-welded deposit | Condition of a weldment before the mandatory 480 °C re-age; strength is well below the aged parent and should not be used as a design basis. | 860 | 1,050 | 12 | 31 HRC | 3.1 % IACS |
Cold drawn | Cold-drawn bar and wire for tighter tolerance and better surface before aging; strain hardening also raises the final aged strength. | 1,030 | 1,170 | 10 | 34 HRC | 3 % IACS |
AgedDefaultThis page Solution annealed + aged 480 °C / 3–6 h, air cool | Standard delivered-strength condition: ~190 ksi UTS with the best toughness of the 18 % Ni maraging series and almost no distortion during aging. | 1,280 | 1,330 | 14 | 40 HRC | 3.8 % IACS |
Vacuum induction melted + vacuum arc remelted | Order this melt route for aerospace/critical rotating parts: lowest inclusion content, best transverse ductility and fracture toughness at the same nominal strength. | 1,300 | 1,340 | 15 | 40 HRC | 3.8 % IACS |
Cold worked then aged 480 °C | Pick when extra strength is needed from thin bar, strip or wire; ductility and toughness drop relative to the plain aged condition. | 1,450 | 1,500 | 8 | 45 HRC | — |
What is 18Ni(190) Aged?
18Ni(190) Aged is 18Ni(190) heat treated to Aged — standard delivered-strength condition: ~190 ksi UTS with the best toughness of the 18 % Ni maraging series and almost no distortion during aging. 18Ni(190) Aged has a yield strength of 1,280 MPa (186 ksi) and a tensile strength of 1,330 MPa (193 ksi) — stronger than 95% of steel grades. Elongation at break is 14% and the elastic modulus is 190 GPa (27.6 Msi). 18Ni(190) 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 — 1,280 MPa (186 ksi), better than 95% of steel grades
- Good corrosion resistance — 25/100, better than 92% of steel grades
- Readily welded — 85/100, better than 83% of steel grades
Limitations
- High embodied carbon — 4.6 kg CO₂/kg, worse than 96% of steel grades
- Poor heat conductor — 20.9 W/m·K (12.1 BTU/hr·ft·°F), worse than 95% of steel grades
- Low electrical conductivity — 3.8 % IACS, worse than 84% of steel grades
- Difficult to machine — 35/100, worse than 84% of steel grades
- Limited formability — 20/100, worse than 80% of steel grades
18Ni(190) Aged properties
Typical room-temperature values for 18Ni(190) Aged; 21 are specific to this condition. Other listed values are 18Ni(190) reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
18Ni(190) 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(190) Aged has a yield strength of 1,280 MPa (186 ksi) and a tensile strength of 1,330 MPa (193 ksi) — stronger than 95% of steel grades. Elongation at break is 14% and the elastic modulus is 190 GPa (27.6 Msi).
Thermal6
18Ni(190) Aged is rated for continuous service to 400°C (752 °F). It conducts heat at 20.9 W/m·K (12.1 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(190) 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(190) Aged takes about 55 MJ of energy and emits 4.6 kg of CO₂ — more than 94% of steel grades. Typical recycled content is 25%.
Manufacturability7
18Ni(190) Aged's machinability is fair (35/100, worse than 84% of steel grades); weldability excellent (85/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 18Ni(190) Aged
Is 18Ni(190) easy to machine?
Rough machine in the annealed condition (~30 HRC) with sharp carbide tools, rigid setups and generous coolant; finish after aging where only ~0.05 % growth occurs, using slow, positive-rake cuts.
Can 18Ni(190) be welded?
Excellent GTAW/EBW/laser weldability with matching filler, no preheat and low heat input; keep the joint clean and re-age at 480 °C after welding to restore strength.
Can 18Ni(190) be formed, bent or molded?
Form, bend, deep-draw or cold-draw only in the solution-annealed state; hot work 1150–900 °C, then re-anneal at 815 °C before aging.
What surface finishes work on 18Ni(190)?
No anodizing; protect with cadmium, nickel or electroless-nickel plating, phosphate or paint, and bake after any plating/pickling to avoid hydrogen embrittlement — nitriding gives a hard 65+ HRC case during aging.
18Ni(190) 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 |
|---|---|---|
| Ckept very low; carbon degrades toughness | ≤ 0.03 | 0.02 |
| Ni | 17 – 19 | 18 |
| Copromotes Mo precipitation | 8 – 9 | 8.5 |
| MoNi3Mo / Fe2Mo aging precipitates | 2.8 – 3.4 | 3.1 |
| Tilower Ti than 250/300 grades — sets the 190 ksi level | 0.1 – 0.25 | 0.18 |
| Al | 0.05 – 0.15 | 0.1 |
| Si | ≤ 0.1 | 0.05 |
| Mn | ≤ 0.1 | 0.05 |
| S | ≤ 0.01 | 0 |
| P | ≤ 0.01 | 0.01 |
| Bgrain-boundary addition, optional | ≤ 0 | 0 |
| Zroptional | ≤ 0.02 | 0.01 |
| Caoptional deoxidizer | ≤ 0.05 | 0.02 |
| Fe | balance | — |
18Ni(190) Aged — frequently asked
What is 18Ni(190) Aged used for?
18Ni(190) Aged is typically used for fracture-critical aerospace fittings, tooling requiring high toughness, pressure vessel components and rocket motor cases (lower-load variants). In short: toughest 18Ni maraging grade; weldable ultra-high-strength steel; near-zero ageing distortion.
What is the yield strength of 18Ni(190) Aged?
18Ni(190) Aged has a typical yield strength of 1,280 MPa (186 ksi) and a tensile strength of 1,330 MPa (193 ksi) — stronger than 95% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 18Ni(190) Aged easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% of steel grades). Rough machine in the annealed condition (~30 HRC) with sharp carbide tools, rigid setups and generous coolant; finish after aging where only ~0.05 % growth occurs, using slow, positive-rake cuts.
Can 18Ni(190) Aged be welded?
Yes — weldability is rated excellent (85/100). Excellent GTAW/EBW/laser weldability with matching filler, no preheat and low heat input; keep the joint clean and re-age at 480 °C after welding to restore strength.
What surface finishes work on 18Ni(190) Aged?
No anodizing; protect with cadmium, nickel or electroless-nickel plating, phosphate or paint, and bake after any plating/pickling to avoid hydrogen embrittlement — nitriding gives a hard 65+ HRC case during aging.
Can 18Ni(190) Aged be formed, bent or molded?
Form, bend, deep-draw or cold-draw only in the solution-annealed state; hot work 1150–900 °C, then re-anneal at 815 °C before aging.
What is the maximum service temperature of 18Ni(190) Aged?
18Ni(190) 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(190) Aged and 18Ni(190)-ANN?
Aged is the default condition — standard delivered-strength condition: ~190 ksi UTS with the best toughness of the 18 % Ni maraging series and almost no distortion during aging. ANN: soft, tough nickel-martensite as supplied for machining, forming and welding before aging. Yield strength is 1,280 MPa in Aged versus 800 MPa in ANN.
Sources
- ASTM A538/A538M — Pressure Vessel Plates, Alloy Steel, Precipitation Hardening (Maraging), 18 % Nickel — ASTM International (2019)
- AMS 6512 / AMS 6520 — 18Ni maraging steel bar, plate and sheet — SAE International (2018)
- ASM Handbook Vol.1, Properties and Selection: Irons, Steels and High-Performance Alloys — Maraging Steels — ASM International (1990)
- ASM Specialty Handbook: Carbon and Alloy Steels — ASM International (1996)
- VascoMax / Marval 18 Ni maraging steel technical data — Carpenter / Aubert & Duval (2020)
- MMPDS-17 maraging steel design allowables (18Ni series) — Battelle (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.