MP35N · UNS R30035
MP35N (R30035): composition, properties, fittings and flanges
MP35N (R30035) is Multiphase age-hardenable cobalt-nickel-chromium-molybdenum alloy. MP35N is specified at Cobalt Balance (about 35 %), Nickel 33.0 - 37.0, Chromium 19.0 - 21.0. MP35N reaches about 1600 MPa by cold work plus ageing, which makes it the standard alloy for high-strength fasteners, springs, and medical and…
- UNS
- R30035
- W. Nr.
- -
- Density
- 8.43 g/cm³ (0.304 lb/in³)
- Key strength
- 1586 MPa / 230 ksi
Identification and standards
| Short form | MP35N · UNS R30035 |
|---|---|
| Classification | Multiphase age-hardenable cobalt-nickel-chromium-molybdenum alloy |
| UNS | R30035 |
| Werkstoff number | - |
| Material family | High-Temperature Alloys / Superalloys |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Cobalt (Co) | Balance (about 35 %) | Matrix and work-hardening response |
| Nickel (Ni) | 33.0 - 37.0 | Austenite stability and corrosion resistance |
| Chromium (Cr) | 19.0 - 21.0 | Corrosion and oxidation resistance |
| Molybdenum (Mo) | 9.00 - 10.50 | Pitting and crevice resistance |
| Titanium (Ti) | 1.00 max | Age hardening |
| Iron (Fe) | 1.00 max | Residual |
| Carbon (C) | 0.025 max | - |
| Phosphorus (P) | 0.015 max | - |
Note Single figures are maximum limits unless shown as a range. Always confirm against the heat-specific EN 10204 3.1 certificate supplied with your order.
Mechanical properties
| Tensile strength, min (aged and cold worked) | 1586 MPa / 230 ksi |
|---|---|
| 0.2 % yield strength, min | 1379 MPa / 200 ksi |
| Elongation in 2 in, min | 12 % |
| Typical hardness, aged | 38 - 46 HRC |
| Maximum recommended service temperature | About 400 °C for full strength |
Warning Values depend on product form, section thickness and heat treatment. Larger sections generally achieve lower strength than thin product; always design against the applicable code allowable stress rather than these figures.
Physical properties
| Density | 8.43 g/cm³ (0.304 lb/in³) |
|---|---|
| Melting range | 1315 - 1440 °C (2400 - 2625 °F) |
| Modulus of elasticity | 233 GPa (33.8 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 11.2 W/m·K |
| Mean coefficient of thermal expansion, 20-100 °C | 12.8 µm/m·°C |
| Specific heat capacity | 420 J/kg·K |
Specifications by product form
| Forgings & flanges | AMS 5844 / ASTM F562 (UNS R30035) |
|---|---|
| Butt weld fittings | Not normally welded - supplied as bar and fastener stock |
| Seamless pipe & tube | ASTM F562 bar and wire forms |
| Plate / sheet / strip | AMS 5845 |
| Bar / rod | AMS 5844 / ASTM F562 / NACE MR0175 |
| Welding consumables | Not recommended; strength comes from cold work and ageing |
| UNS / EN / China | UNS R30035 · NACE MR0175 listed |
Product forms available
Hangbo supplies this grade in the following forms. Sizes outside the listed range can often be produced to order.
- Forged flanges blanks and finished flanges to ASME B16.5, B16.47 Series A/B and B16.36
- Butt weld elbows, tees, reducers, caps and stub ends to ASME B16.9 and MSS SP-43
- Seamless pipe and tube to the applicable ASTM / ASME pipe specification
- Forged rings, discs and hubs machined to your drawing
Typical applications
- High-strength fasteners, springs and locking hardware
- Sour service and seawater components needing NACE compliance
- Medical implants, catheters and orthopaedic cable
- Aerospace and motorsport critical fasteners
Welding, forming and machining
- Welding
- Welding is not recommended because strength comes from cold work plus ageing. Components are machined from bar in the required strength condition.
- Heat treatment
- Anneal at 1095 °C, then cold work and age at 540 - 650 °C to reach the specified strength level.
- Hot and cold forming
- Hot work in the range stated by the mill for this grade, then re-solution or re-age before final machining so that the delivered condition matches the certificate.
- Machining
- Machine with sharp carbide or high-speed steel tooling, positive rake, constant feed and ample coolant. Never dwell - the surface work-hardens quickly.
Buy MP35N from Hangbo
Material is supplied with full heat-number traceability, solution annealing or ageing performed under calibrated furnace control, and an EN 10204 3.1 certificate covering chemical analysis, mechanical properties, heat treatment records and the agreed NDT scope. Positive material identification and third party inspection and test reports from SGS are available for critical service.