In short
What is Maraging 200?
Maraging 200 is an 18 % nickel maraging steel with a nominal composition of 18Ni-8.5Co-3.2Mo-0.20Ti-0.10Al and a carbon content below 0.03 %. It is also designated Maraging C200, 18Ni(200) and UNS K92810. The alloy hardens by ageing at 480 °C (900 °F), which precipitates nickel-molybdenum and nickel-titanium intermetallics in a low-carbon iron-nickel martensite. Minimum tensile strength after ageing is 1410 MPa (205 ksi). No quench is required, and the part contracts by 0.04 to 0.08 % during ageing. Of the four grades in the 18 % nickel maraging family, grade 200 has the lowest strength and the highest toughness.
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin, Jiangsu, China. The company forges Maraging 200 rolled rings, flanges, shafts, discs, bars, sleeves, bushings, tube sheets and valve parts to customer drawing, supplied solution annealed for machining or annealed and aged. Enquiries: sales@steelforgepieces.com, 0086-189-2135-9659.
Last reviewed 21 August 2026. Maintained by the Jiangyin Jiangnan Metal engineering team.
Maraging 200 equivalents and cross-reference
Maraging 200 is covered by American specifications. There is no DIN, EN or JIS equivalent, and the nearest Chinese grade is comparable rather than interchangeable. All designations in the table describe the same 18Ni-8.5Co-3.2Mo-0.20Ti chemistry. Send whichever one appears on your drawing and Jiangyin Jiangnan Metal will quote against it.
| System / region | Designation | Notes |
|---|---|---|
| Common trade names | Maraging 200, Maraging C200, Maraging C-200, Marage 200 | Used interchangeably in enquiries |
| Alloy family | 18Ni(200), 18Ni-200 | Metallurgical designation |
| UNS (USA) | K92810 | Unified Numbering System |
| SAE AMS, forgings | AMS 6511 | Bars, forgings, mechanical tubing, flash welded rings and forging stock. 18Ni-8.5Co-3.2Mo-0.20Ti-0.10Al, double vacuum melted, annealed |
| ASTM, plate | ASTM A538 Grade A | Pressure vessel plates, precipitation hardening (maraging), 18 % nickel |
| ASTM, forgings | ASTM A579 Grade 71 | Superstrength alloy steel forgings |
| US military | MIL-S-46850 Type 200 | Bar, plate, sheet, strip, forgings and tubing |
| China, nearest grade | 00Ni18Co8Mo3TiAl | Comparable domestic grade, not a certified substitution for AMS 6511 |
| DIN / EN / JIS | No formal equivalent | Order to AMS 6511 or ASTM A538 Grade A |
Sources: SAE AMS 6511, ASTM A538/A538M, ASTM A579/A579M, MIL-S-46850, and the Nickel Institute publication 18 % Nickel Maraging Steel, Engineering Properties.
Chemical composition of Maraging 200
The chemical composition of Maraging 200 (UNS K92810) is controlled to the limits below, in weight percent. Cobalt and molybdenum drive the precipitation reaction, and titanium has the strongest effect on aged strength. Residual elements are held low because maraging steels are sensitive to inclusions and to hydrogen. Jiangyin Jiangnan Metal melts Maraging 200 by VIM + VAR (vacuum induction melting followed by vacuum arc remelting) or VIM + ESR. Air melting does not reliably deliver the low hydrogen and low oxide content required at this strength level.
| Element | Symbol | Nominal aim | Range or limit | Function |
|---|---|---|---|---|
| Iron | Fe | Balance | Matrix | |
| Nickel | Ni | 18.5 | 17.0 to 19.0 | Forms the soft iron-nickel martensite |
| Cobalt | Co | 8.5 | 8.0 to 9.0 | Lowers Mo solubility, promotes precipitation |
| Molybdenum | Mo | 3.25 | 3.00 to 3.50 | Forms Ni3Mo and Fe2Mo strengthening phases |
| Titanium | Ti | 0.20 | 0.15 to 0.25 | Forms Ni3Ti, strongest effect on aged strength |
| Aluminium | Al | 0.10 | 0.05 to 0.15 | Deoxidiser, secondary hardening |
| Carbon | C | n/a | 0.03 max | Held low, carbides would embrittle |
| Manganese | Mn | n/a | 0.10 max | Residual |
| Silicon | Si | n/a | 0.10 max | Residual |
| Phosphorus | P | n/a | 0.010 max | Embrittling at grain boundaries |
| Sulphur | S | n/a | 0.010 max | Controls inclusion content |
| Zirconium | Zr | n/a | 0.01 max | Grain refinement |
| Boron | B | n/a | 0.003 max | Grain boundary strengthening |
Nominal aim values follow the AMS 6511 alloy designation 18Ni-8.5Co-3.2Mo-0.20Ti-0.10Al. Ranges are typical specification limits. The certified heat analysis is issued with every order. State the required melting route (VIM+VAR or VIM+ESR) on the enquiry, because it affects both price and lead time.
Mechanical and physical properties
Maraging 200 is supplied in two conditions. In the solution annealed condition it is soft enough to machine, form and weld. Ageing at 480 °C raises the strength to specification level. Jiangyin Jiangnan Metal supplies forgings in either condition.
- Hardness
- 27 to 32 HRC
- Tensile
- about 1000 MPa (145 ksi)
- Yield
- about 800 MPa (116 ksi)
- Elongation
- 15 to 18 %
- Work done
- Machine, form, weld, straighten
- Hardness
- 42 to 46 HRC
- Tensile
- 1410 MPa min (205 ksi)
- Yield
- 1380 MPa min (200 ksi)
- Elongation
- 8 % min
- Work done
- Grind, plate, nitride, use
Figures in bold are specification minima certified on the EN 10204 test report. Other figures are typical published values for the grade.
| Property | Solution annealed | Aged 480 °C |
|---|---|---|
| Tensile strength | about 1000 MPa / 145 ksi | 1410 MPa / 205 ksi min |
| Yield strength, 0.2 % offset | about 800 MPa / 116 ksi | 1380 MPa / 200 ksi min |
| Elongation in 4D | 15 to 18 % | 8 % min |
| Reduction of area | 65 to 70 % | 55 to 60 % |
| Hardness | 27 to 32 HRC | 42 to 46 HRC |
| Charpy V-notch impact | Very high | 34 J / 25 ft·lbf typical |
| Fracture toughness KIC | n/a | 150 to 200 MPa·m0.5 |
| Modulus of elasticity | about 180 GPa / 26 Msi | about 186 GPa / 27 Msi |
Indicative values, not for design. Properties vary with section size, forging reduction and heat treatment route. Jiangyin Jiangnan Metal issues certified test results for each heat and each forging lot. Request the mill test report before finalising a design.
| Property | Metric | Imperial |
|---|---|---|
| Density | 8.0 g/cm³ | 0.289 lb/in³ |
| Melting range | 1430 to 1450 °C | 2606 to 2642 °F |
| Mean CTE, 20 to 300 °C | 10.1 to 10.3 µm/m·K | 5.6 to 5.7 µin/in·°F |
| Thermal conductivity, 20 °C | 19.7 to 25.5 W/m·K | 137 to 177 Btu·in/h·ft²·°F |
| Specific heat capacity | about 452 J/kg·K | about 0.108 Btu/lb·°F |
| Electrical resistivity | 0.55 to 0.65 µΩ·m | n/a |
| Poisson's ratio | 0.31 | |
| Magnetic response | Ferromagnetic in both conditions | |
| Dimensional change on ageing | Contraction 0.04 to 0.08 % (0.0004 to 0.0008 in/in) | |
Maraging 200 compared with 250, 300 and 350
The grade number is approximately the aged tensile strength in ksi. Strength rises with cobalt, molybdenum and titanium content, while fracture toughness and stress-corrosion resistance fall. Jiangyin Jiangnan Metal forges all four grades, and all four follow the same route: solution anneal, machine, age at 480 °C.
| Grade | UNS | Forging spec | Co / Mo / Ti | Aged tensile | Aged hardness | Selection |
|---|---|---|---|---|---|---|
| Maraging 200 | K92810 | AMS 6511 | 8.5 / 3.2 / 0.20 | 1410 MPa 205 ksi |
42 to 46 HRC | Toughness, thick sections and crack tolerance rank above peak strength |
| Maraging 250 | K92890 | AMS 6512 | 7.8 / 4.9 / 0.40 | 1725 MPa 250 ksi |
48 to 50 HRC | General purpose grade, balanced strength and toughness |
| Maraging 300 | K93120 | AMS 6514 | 9.0 / 4.9 / 0.65 | 2000 MPa 290 ksi |
51 to 55 HRC | Strength to weight is critical and sections are modest |
| Maraging 350 | K93160 | AMS 6515 | 12.0 / 4.9 / 1.40 | 2400 MPa 350 ksi |
54 to 58 HRC | Maximum strength required, lowest toughness of the family |
If the drawing states only "maraging steel", send the required tensile minimum and the ruling section and we will confirm the grade before quoting.
Forging and heat treatment of Maraging 200
Maraging 200 forges more easily than a nickel or cobalt superalloy, because at forging temperature it is a soft, ductile iron-nickel structure. Grain size control is the main concern: coarse grain reduces the toughness that makes grade 200 preferable to grade 250 in the first place. Jiangyin Jiangnan Metal forges Maraging 200 on hydraulic open-die presses, with ring rolling for seamless rings.
| Operation | Temperature | Practice |
|---|---|---|
| Soak before forging | 1150 to 1260 °C / 2100 to 2300 °F | Hold only until the section is uniformly at temperature. Longer soaks coarsen the grain |
| Finishing temperature | 815 °C / 1500 °F minimum | Air cool from finish. Minimum 3:1 reduction from the remelted ingot |
| Solution anneal | 815 to 830 °C / 1500 to 1525 °F | 1 h per 25 mm of ruling section, air cool. No quenchant, so no quench distortion or cracking |
| Ageing | 480 °C ± 6 °C / 900 °F ± 10 °F | 3 to 6 h, air cool. Furnace uniformity is critical, since an overheated zone over-ages and loses strength |
| Stress relief or re-age | 480 °C | Restores properties after unavoidable cold straightening |
| Nitriding, optional | about 480 °C | Can be carried out at the ageing temperature, giving a hard wear case in the same cycle |
Straighten long forgings in the annealed condition. Cold straightening a part that is already at 1400 MPa introduces residual stress into an ultra-high-strength steel. Where it cannot be avoided, follow it with a stress relief age at 480 °C.
Machining
Machine Maraging 200 in the solution annealed condition at 27 to 32 HRC, where machinability is comparable to a medium carbon alloy steel of similar hardness. Use rigid setups, sharp positive rake carbide tooling, generous coolant, and moderate speeds with a healthy feed, because the alloy work hardens if a dull tool rubs rather than cuts. Set finished dimensions with an allowance for the 0.04 to 0.08 % contraction that occurs during ageing. Grinding after ageing is straightforward.
Welding
Carbon is below 0.03 %, so Maraging 200 does not form a hard, crack prone heat affected zone and needs no preheat. Weld in the annealed condition by GTAW or electron beam with matching filler, using low heat input and clean, dry, oil free joint preparation, then age the completed assembly at 480 °C so that weld metal, heat affected zone and parent metal harden together. Keep moisture and other hydrogen sources away from the joint.
Maraging 200 forged product forms
All items below are made to customer drawing. Jiangyin Jiangnan Metal does not hold standard Maraging 200 stock, because double melted maraging steel is bought against the order. Send a drawing, a sketch, or finished dimensions plus a machining allowance.
| Forged form | Indicative size range | Typical use |
|---|---|---|
| Seamless rolled rings | OD 200 to 2500 mm, H 600 mm max | Bearing races, coupling rings, tooling rings |
| Forged flanges | To drawing | Pressure vessel and structural connections |
| Forged discs and blanks | OD 100 to 1200 mm | Gear blanks, coupling discs, die bolsters |
| Forged round bar and blocks | Dia 50 to 500 mm, L 4000 mm max | Machining stock, punches, fasteners, spindles |
| Forged shafts and eccentric shafts | Dia 80 to 500 mm, L 5000 mm max | Transmission and drive shafts, pump shafts, spindles |
| Sleeves and bushings | OD 100 to 1200 mm | Bearing housings, wear sleeves, hollow bar stock |
| Tube sheets and forged tubes | To drawing | Heavy plate forgings, trepanned or expanded hollows |
| Valve bodies, seat rings, stems, blocks | To drawing | Ball, gate, globe, check and plug valves |
| Nozzles, manifolds, forging rolls, wheels | To drawing | Process units, tooling and heavy machinery |
| Single piece weight | 5 kg to 3000 kg | Heavier pieces on enquiry |
Sizes are indicative. Maraging 200 is a premium double melted alloy, so the cost of a forged part is dominated by input weight. Send a machining drawing rather than a billet size, so the forging envelope can be designed to reduce the buy-to-fly ratio. Confirm limits for your geometry with sales@steelforgepieces.com.
Applications of Maraging 200 forgings
Maraging 200 is normally specified for one of three reasons: the part must harden after machining without distorting, the design needs high strength together with damage tolerance, or the assembly is welded and must reach full strength afterwards. The industries below account for most Maraging 200 forgings shipped by Jiangyin Jiangnan Metal.
| Industry | Components forged in Maraging 200 |
|---|---|
| Tooling and die work | Die holders and bolsters, extrusion press components, hot forming and hydroforming tooling, injection mould bases, punches and die inserts that must not distort on hardening |
| Aerospace structure and mechanisms | Structural fittings, actuator bodies, high strength shafting, couplings, flexures and load carrying hardware |
| Motorsport and high performance drivetrain | Transmission shafts, gear blanks, driveshafts and coupling components where torque density is the constraint |
| Springs and precision elastic elements | Belleville springs, load cells, flexure pivots and diaphragms that need high strength with a stable modulus |
| Rotating and reciprocating machinery | Pump and plunger pump shafts, compressor and gearbox shafting, spindles, eccentric shafts, forging rolls |
| Pressure vessels and process equipment | Forged flanges, tube sheets, sleeves and bodies where ASTM A538 Grade A is invoked |
| Valves and flow control | Valve bodies, seat rings, stems, gate blanks and blocks |
| Fasteners and bolting | High strength bolts, studs, couplings and threaded components |
| Oil, gas and offshore | Subsea and wellhead hardware, manifolds, forged nozzles, high strength connectors |
Manufacturing and verification sequence
A Maraging 200 order runs through six stages. Machining comes before ageing, because all significant metal removal is done while the part is still soft.
Testing, NDT and certification
Jiangyin Jiangnan Metal ultrasonically tests Maraging 200 forgings to the standard named on the purchase order, and supplies a material certificate with every shipment.
- Ultrasonic testing: EN 10228-3, SEP 1921, ASTM A388 or an equivalent customer standard, to the acceptance class specified.
- Surface NDT: magnetic particle or liquid penetrant. Maraging 200 is ferromagnetic, so magnetic particle inspection is available.
- Chemical analysis: ladle and product analysis by spectrometer, per heat.
- Mechanical testing: tensile and hardness in the aged condition as standard, Charpy V-notch on request. Test coupons are cut from prolongations integral to the forging where the specification requires it.
- Grain size and microstructure: ASTM E112 on request, with photomicrographs.
- Material certificate: EN 10204 3.1 as standard, or EN 10204 3.2 countersigned by an independent third party.
- Marking and traceability: heat number, lot number and specification hard stamped or vibro etched on each piece.
Maraging 200 questions and answers
What is Maraging 200 steel?
Maraging 200, also written Maraging C200 or 18Ni(200), is an ultra-high-strength iron-nickel alloy steel containing nominally 18 % nickel, 8.5 % cobalt, 3.2 % molybdenum and 0.20 % titanium, with carbon below 0.03 %. It hardens by intermetallic precipitation during a low temperature ageing treatment at 480 °C rather than by carbon and quenching, so it reaches 1410 MPa tensile strength with very little distortion. Its UNS number is K92810, and it has the lowest strength and highest toughness of the four 18 % nickel maraging grades.
Which specification should be quoted for Maraging 200 forgings?
For forgings, rings, bars and mechanical tubing, quote AMS 6511. That is the SAE specification whose alloy designation, 18Ni-8.5Co-3.2Mo-0.20Ti-0.10Al, matches Maraging 200 chemistry. ASTM A538 Grade A covers maraging pressure vessel plate, ASTM A579 Grade 71 covers superstrength alloy steel forgings, and MIL-S-46850 Type 200 covers US military procurement. AMS 6520 is sometimes quoted by mistake, but it is a Maraging 250 sheet, strip and plate specification with a different composition.
What is the UNS number for Maraging 200, and is there a DIN or GB equivalent?
Maraging 200 is UNS K92810. There is no formally standardised DIN, EN or JIS equivalent, and the nearest Chinese grade, 00Ni18Co8Mo3TiAl, is comparable rather than a certified substitution. Purchase orders should therefore name AMS 6511 or ASTM A538 Grade A as the controlling specification instead of relying on a nominal equivalence.
What are the mechanical properties of Maraging 200 after ageing?
After solution annealing and ageing at 480 °C, Maraging 200 develops a minimum tensile strength of 1410 MPa (205 ksi), a minimum 0.2 % offset yield strength of 1380 MPa (200 ksi), minimum elongation of 8 %, and a hardness of 42 to 46 HRC. In the solution annealed condition it is much softer at 27 to 32 HRC, which is the condition in which it is machined, formed and welded.
How is Maraging 200 heat treated?
Forge at 1150 to 1260 °C, finishing no lower than 815 °C, and air cool. Solution anneal at 815 to 830 °C for one hour per 25 mm of section and air cool, which gives soft iron-nickel martensite at 27 to 32 HRC. Machine the part in that condition. Then age at 480 °C plus or minus 6 °C (900 °F plus or minus 10 °F) for 3 to 6 hours and air cool. No quench is used at any stage, and the part contracts by a predictable 0.04 to 0.08 % during ageing.
What is the difference between Maraging 200, 250, 300 and 350?
The grade number is approximately the tensile strength in ksi. Maraging 200 reaches about 1410 MPa (205 ksi), Maraging 250 about 1725 MPa (250 ksi), Maraging 300 about 2000 MPa (290 ksi) and Maraging 350 about 2400 MPa (350 ksi). Strength rises with cobalt, molybdenum and especially titanium content, while fracture toughness falls and sensitivity to stress-corrosion cracking increases. NASA testing of all four grades found grade 200 the least susceptible to stress-corrosion cracking and grade 350 the most, so Maraging 200 is selected where toughness and crack tolerance rank above peak strength.
Can Maraging 200 be welded?
Yes. Because carbon is below 0.03 %, Maraging 200 does not form a hard, crack prone heat affected zone, which makes it one of the most weldable ultra-high-strength steels. It is normally welded by GTAW or electron beam in the solution annealed condition with matching filler and without preheat, and the whole assembly is then aged at 480 °C so that weld and parent metal harden together. Joints should be clean and dry, since maraging steels are sensitive to hydrogen.
Is Maraging 200 corrosion resistant?
No. Maraging 200 is not a stainless steel. It contains no deliberate chromium addition and will rust in damp air, so parts are normally protected by cadmium or zinc-nickel plating, nitriding, phosphating or paint. Nitriding is convenient because it can be carried out at the ageing temperature. General corrosion resistance is somewhat better than a quenched and tempered low alloy steel of similar strength, and among the 18 % nickel maraging grades it is the most resistant to stress-corrosion cracking.
What forged shapes and sizes of Maraging 200 can Jiangyin Jiangnan Metal supply?
Jiangyin Jiangnan Metal Co., Ltd. open-die forges Maraging 200 into seamless rolled rings, flanges, discs and blanks, round bar and blocks, shafts and eccentric shafts, sleeves, bushings, tube sheets, forged tubes, valve bodies, seat rings and stems, nozzles, manifolds, forging rolls and wheels. Everything is made to customer drawing rather than to a stock catalogue, so the practical limit is the piece weight and diameter agreed at enquiry.
What certificates and NDT come with a Maraging 200 forging?
Every Maraging 200 forging ships with an EN 10204 3.1 mill certificate covering heat number, chemical analysis, heat treatment condition, mechanical test results and NDT results. An EN 10204 3.2 certificate countersigned by an independent inspection body is available when the purchase order requires it. Ultrasonic acceptance follows EN 10228-3, SEP 1921 or ASTM A388 to the class specified.
How is Maraging 200 machined?
Maraging 200 is machined in the solution annealed condition at 27 to 32 HRC, where its machinability is similar to a medium carbon alloy steel. Use rigid setups, sharp carbide tooling, positive rake, generous coolant, and moderate speeds with a heavier feed, because the alloy work hardens if the tool rubs rather than cuts. Allow for the shrinkage of 0.04 to 0.08 % that occurs during ageing when setting finished dimensions.
What lead time and minimum order applies to Maraging 200 forgings?
Maraging 200 is not a stock item in most sizes, so lead time depends on the availability of double melted raw material plus forging, heat treatment and testing. Confirm current lead time and minimum order value with Jiangyin Jiangnan Metal Co., Ltd. at enquiry stage, since both depend on piece weight, quantity and the melting route specified.
Request a Maraging 200 quotation
Send the size or the drawing of the Maraging 200 forging required. We quote to that drawing, with the specification, delivery condition, NDT class and certificate level nominated by you.
- Company
- Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory
- Address
- No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Phone
- 0086-189-2135-9659
- sales@steelforgepieces.com
- Website
- www.steelforgepieces.com
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