Refractory Metal Mo-41Re ARC-CAST
Grade
ASTM B387 Grade 366
Use for large forged or machined blanks and high-purity, low-interstitial stock; coarser grain and lower as-cast strength than wrought PM product.
Values for the ARC-CAST condition
Other Mo-41Re tempers and conditions
Mo-41Re is listed in 4 conditions; see the grade overview at Mo-41Re.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ARC-CASTThis page Arc-cast / EB-melted ingot and forged bar | Use for large forged or machined blanks and high-purity, low-interstitial stock; coarser grain and lower as-cast strength than wrought PM product. | 480 | 780 | 18 | 21 HRC | 6.3 % IACS |
Recrystallized | Pick when maximum ductility and deep-forming/welding capability are needed, or where service temperature will recrystallize the part anyway. | 520 | 850 | 25 | 22 HRC | — |
SRDefault Stress relieved | Standard stocked condition for sheet, rod and thermocouple wire — good strength with useful room-temperature ductility and dimensional stability. | 900 | 1,100 | 15 | 33 HRC | — |
Cold worked | Highest strength condition for springs, fine wire and thin foil where maximum stiffness-per-section and strength matter more than ductility. | 1,300 | 1,450 | 8 | 42 HRC | — |
What is Mo-41Re ARC-CAST?
Mo-41Re ARC-CAST is Mo-41Re in the ARC-CAST grade — use for large forged or machined blanks and high-purity, low-interstitial stock; coarser grain and lower as-cast strength than wrought PM product. Mo-41Re ARC-CAST has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 72% of refractory metal grades. Elongation at break is 18% and the elastic modulus is 355 GPa (51.5 Msi). Mo-41Re ARC-CAST has a density of 13.6 g/cm³ (0.491 lb/in³), heavier than 81% of refractory metal grades. It melts at 2,500°C (4,532 °F). SR is the default condition FabDigit quotes; ARC-CAST is available on request or by drawing note.
Advantages
- High service temperature — 1,800°C (3,272 °F), better than 91% of refractory metal grades
- Stiff — 355 GPa (51.5 Msi), better than 90% of refractory metal grades
Limitations
- Heavy — 13.6 g/cm³ (0.491 lb/in³), worse than 81% of refractory metal grades
- Difficult to machine — 20/100, worse than 77% of refractory metal grades
Mo-41Re ARC-CAST properties
Typical room-temperature values for Mo-41Re ARC-CAST; 23 are specific to this condition. Other listed values are Mo-41Re reference data and may not represent this condition. Bars are the position among refractory metal grades.
Physical3
Mo-41Re ARC-CAST has a density of 13.6 g/cm³ (0.491 lb/in³), heavier than 81% of refractory metal grades. It melts at 2,500°C (4,532 °F).
Mechanical13
Mo-41Re ARC-CAST has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 72% of refractory metal grades. Elongation at break is 18% and the elastic modulus is 355 GPa (51.5 Msi).
Thermal6
Mo-41Re ARC-CAST is rated for continuous service to 1,800°C (3,272 °F). It conducts heat at 48 W/m·K (27.7 BTU/hr·ft·°F), better than 61% of refractory metal grades. Thermal expansion is 5.8 µm/m·K (3.22 µin/in·°F).
Electrical3
Mo-41Re ARC-CAST conducts electricity at 6.3 % IACS, better than 52% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 66% of refractory metal grades.
Sustainability3
Producing a kilogram of Mo-41Re ARC-CAST takes about 900 MJ of energy and emits 60 kg of CO₂ — less than 59% of refractory metal grades. Typical recycled content is 40%.
Manufacturability7
Mo-41Re ARC-CAST's machinability is poor (20/100, worse than 77% of refractory metal grades); weldability very good (72/100); formability good (64/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Mo-41Re ARC-CAST
Is Mo-41Re easy to machine?
Tough and work-hardening — use sharp, positive-rake carbide or ground HSS, rigid setups, low speed with heavy positive feed and flood coolant; grinding and EDM are common for finish features.
Can Mo-41Re be welded?
Weldable by EB or GTAW in high vacuum or high-purity argon; unlike pure Mo the welds retain room-temperature ductility, but interstitial pickup (O, N, C) must be avoided.
Can Mo-41Re be formed, bent or molded?
Cold rollable to thin foil and drawable to fine wire with intermediate vacuum anneals; warm forming at 200–600 °C eases severe bends in heavy section.
What surface finishes work on Mo-41Re?
Chemically or electropolished to bright finish; not anodizable — use Si-Cr-Fe pack cementation, iridium or CVD coatings for any oxidizing high-temperature exposure.
Mo-41Re 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 |
|---|---|---|
| Reat the practical solubility limit before sigma/chi embrittlement | 39.5 – 42.5 | 41 |
| C | ≤ 0.01 | 0.01 |
| O | ≤ 0.01 | 0 |
| N | ≤ 0 | 0 |
| Fe | ≤ 0.01 | — |
| Ni | ≤ 0.01 | — |
| Si | ≤ 0.01 | — |
| Mo | balance | — |
Mo-41Re ARC-CAST — frequently asked
What is Mo-41Re ARC-CAST used for?
Mo-41Re ARC-CAST is typically used for type C thermocouple wire, X-ray tube targets, rocket nozzle liners and precision springs/foils. In short: ductile, weldable molybdenum; type C thermocouple alloy; costliest Mo alloy.
What is the yield strength of Mo-41Re ARC-CAST?
Mo-41Re ARC-CAST has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 72% of refractory metal grades. Strength varies by condition: see the 4 listed tempers.
Is Mo-41Re ARC-CAST easy to machine?
Not especially — machinability is rated poor (20/100, worse than 77% of refractory metal grades). Tough and work-hardening — use sharp, positive-rake carbide or ground HSS, rigid setups, low speed with heavy positive feed and flood coolant; grinding and EDM are common for finish features.
Can Mo-41Re ARC-CAST be welded?
Yes — weldability is rated very good (72/100). Weldable by EB or GTAW in high vacuum or high-purity argon; unlike pure Mo the welds retain room-temperature ductility, but interstitial pickup (O, N, C) must be avoided.
What surface finishes work on Mo-41Re ARC-CAST?
Chemically or electropolished to bright finish; not anodizable — use Si-Cr-Fe pack cementation, iridium or CVD coatings for any oxidizing high-temperature exposure.
Can Mo-41Re ARC-CAST be formed, bent or molded?
Cold rollable to thin foil and drawable to fine wire with intermediate vacuum anneals; warm forming at 200–600 °C eases severe bends in heavy section.
What is the maximum service temperature of Mo-41Re ARC-CAST?
Mo-41Re ARC-CAST is rated for continuous use to about 1,800°C (3,272 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Mo-41Re-SR and Mo-41Re-CW?
SR is the default condition — standard stocked condition for sheet, rod and thermocouple wire — good strength with useful room-temperature ductility and dimensional stability. CW: highest strength condition for springs, fine wire and thin foil where maximum stiffness-per-section and strength matter more than ductility. Yield strength is 900 MPa in SR versus 1,300 MPa in CW.
Sources
- ASTM B387 — Molybdenum and Molybdenum Alloy Bar, Rod, and Wire — ASTM International (2018)
- Molybdenum-Rhenium Alloy (Mo-41Re, Mo-47.5Re) technical data — Rhenium Alloys, Inc. (2022)
- Molybdenum alloys — material properties — Plansee SE (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Refractory Metals) — ASM International (1990)
- ASM Handbook Vol.3 — Alloy Phase Diagrams (Mo-Re system) — ASM International (1992)
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.