Haynes 242 · UNS N10242
Haynes 242 (N10242): composition, properties, fittings and flanges
Haynes 242 (N10242) is Age-hardenable nickel-molybdenum-chromium alloy. Haynes 242 is specified at Nickel Balance, Molybdenum 24.0 - 26.0, Chromium 7.00 - 9.00. Haynes 242 ages to high strength through a long-range ordered Ni2(Cr,Mo) phase instead of gamma-prime, giving low thermal expansion, high strength to 705 °C and…
- UNS
- N10242
- W. Nr.
- -
- Density
- 9.05 g/cm³ (0.327 lb/in³)
- Key strength
- 1000 MPa / 145 ksi
Identification and standards
| Short form | Haynes 242 · UNS N10242 |
|---|---|
| Classification | Age-hardenable nickel-molybdenum-chromium alloy |
| UNS | N10242 |
| Werkstoff number | - |
| Material family | High-Temperature Alloys / Superalloys |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Nickel (Ni) | Balance | Matrix |
| Molybdenum (Mo) | 24.0 - 26.0 | Ordered phase formation and strength |
| Chromium (Cr) | 7.00 - 9.00 | Oxidation resistance |
| Cobalt (Co) | 2.50 max | Residual |
| Iron (Fe) | 2.00 max | Residual |
| Carbon (C) | 0.03 max | - |
| Manganese (Mn) | 0.80 max | - |
| Boron (B) | 0.006 max | Grain boundary control |
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) | 1000 MPa / 145 ksi |
|---|---|
| 0.2 % yield strength, min | 690 MPa / 100 ksi |
| Elongation in 2 in, min | 20 % |
| Typical hardness, aged | 30 - 38 HRC |
| Coefficient of thermal expansion, 20-600 °C | About 12.6 µm/m·°C |
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 | 9.05 g/cm³ (0.327 lb/in³) |
|---|---|
| Melting range | 1290 - 1350 °C (2355 - 2460 °F) |
| Modulus of elasticity | 229 GPa (33.2 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 10.2 W/m·K |
| Mean coefficient of thermal expansion, 20-100 °C | 11.0 µm/m·°C |
| Specific heat capacity | 415 J/kg·K |
Specifications by product form
| Forgings & flanges | ASTM B564 / AMS 5708 family (UNS N10242) |
|---|---|
| Butt weld fittings | ASTM B366 (WP grade to order) |
| Seamless pipe & tube | To order against ASTM B622 requirements |
| Plate / sheet / strip | ASTM B434 family |
| Bar / rod | ASTM B573 family |
| Welding consumables | Matching Haynes 242 filler |
| UNS / EN / China | UNS N10242 |
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
- Seal rings and casings where low thermal growth is needed
- Fluoride and molten salt handling equipment
- Hot-section fasteners and springs
- Chemical process components needing strength to 705 °C
Welding, forming and machining
- Welding
- Weldable with matching filler, but the ageing response in the weld metal differs from the parent. Age the finished fabrication, not the separate pieces.
- Heat treatment
- Solution anneal at 1105 - 1175 °C, then age at 650 °C for 24 to 72 hours depending on required strength.
- 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 Haynes 242 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.