Refractory Metal R04210 Annealed
Temper · default condition
UNS R04210 · ASTM B393 Type 2
Default stock condition for sheet, plate, rod and tube; maximum ductility for deep drawing, spinning and forming.
Values for the Annealed condition
Other R04210 tempers and conditions
R04210 is listed in 3 conditions; see the grade overview at R04210.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefaultThis page fully recrystallized (vacuum annealed) | Default stock condition for sheet, plate, rod and tube; maximum ductility for deep drawing, spinning and forming. | 115 | 200 | 40 | 70 HB | — |
Stress relieved | Pick when dimensional stability and moderate strength are needed without losing all cold-work strengthening. | 250 | 320 | 20 | 105 HB | 11.5 % IACS |
Cold worked | Highest room-temperature strength for springs, fasteners and thin foil where no recrystallization anneal follows. | 420 | 470 | 8 | 140 HB | — |
What is R04210 Annealed?
R04210 Annealed is R04210 in the Annealed temper — default stock condition for sheet, plate, rod and tube; maximum ductility for deep drawing, spinning and forming. R04210 Annealed has a yield strength of 115 MPa (16.7 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 100% of refractory metal grades. Elongation at break is 40% and the elastic modulus is 103 GPa (14.9 Msi). R04210 Annealed has a density of 8.57 g/cm³ (0.31 lb/in³), heavier than 51% of refractory metal grades. It melts at 2,468°C (4,474 °F).
Advantages
- Forms and bends easily — 95/100, better than 99% of refractory metal grades
- Ductile — tolerates forming and impact — 40%, better than 96% of refractory metal grades
- Low embodied carbon — 22 kg CO₂/kg, better than 83% of refractory metal grades
Limitations
- Low strength — 115 MPa (16.7 ksi), worse than 100% of refractory metal grades
R04210 Annealed properties
Typical room-temperature values for R04210 Annealed; 12 are specific to this condition. Other listed values are R04210 reference data and may not represent this condition. Bars are the position among refractory metal grades.
Physical3
R04210 Annealed has a density of 8.57 g/cm³ (0.31 lb/in³), heavier than 51% of refractory metal grades. It melts at 2,468°C (4,474 °F).
Mechanical13
R04210 Annealed has a yield strength of 115 MPa (16.7 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 100% of refractory metal grades. Elongation at break is 40% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
R04210 Annealed is rated for continuous service to 400°C (752 °F). It conducts heat at 53.7 W/m·K (31 BTU/hr·ft·°F), better than 64% of refractory metal grades. Thermal expansion is 7.3 µm/m·K (4.06 µin/in·°F).
Electrical3
R04210 Annealed conducts electricity at 11.9 % IACS, better than 65% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 64% of refractory metal grades.
Sustainability4
Producing a kilogram of R04210 Annealed takes about 320 MJ of energy and emits 22 kg of CO₂ — less than 83% of refractory metal grades. Typical recycled content is 25%.
Manufacturability8
R04210 Annealed's machinability is poor (28/100, worse than 58% of refractory metal grades); weldability very good (70/100); formability excellent (95/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with R04210 Annealed
Is R04210 easy to machine?
Gummy and galling-prone: use sharp, positive-rake carbide or HSS tooling, slow speeds, heavy feeds, flood chlorinated or sulfurized coolant, and avoid dwelling to prevent smearing and work hardening.
Can R04210 be welded?
GTAW/EBW/laser weld readily but must be done in a vacuum chamber or with complete trailing/backing inert gas — any O, N or H pickup above ~250 °C embrittles the weld; use Nb or Nb-1Zr filler.
Can R04210 be formed, bent or molded?
Outstanding cold formability — deep drawing, spinning and >90 % cold rolling reduction are routine with intermediate vacuum anneals at 1100–1300 °C; use non-galling tooling coatings or lubricated interleaf.
What surface finishes work on R04210?
Pickle in HF-HNO3 or buffered chemical polish, electropolish for SRF/UHV surfaces; anodizing gives decorative Nb2O5 interference colours; avoid iron contamination during grinding.
R04210 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 |
|---|---|---|
| Tarelaxed vs reactor grade Type 1 | ≤ 0.3 | 0.1 |
| W | ≤ 0.05 | 0.01 |
| Mo | ≤ 0.02 | 0.01 |
| Zr | ≤ 0.02 | 0.01 |
| Ti | ≤ 0.03 | 0.01 |
| Hf | ≤ 0.02 | 0.01 |
| Fe | ≤ 0.01 | 0 |
| Ni | ≤ 0.01 | 0 |
| Si | ≤ 0.01 | 0 |
| C | ≤ 0.01 | 0 |
| O | ≤ 0.03 | 0.01 |
| N | ≤ 0.01 | 0 |
| H | ≤ 0 | 5×10⁻⁴ |
| Nbbalance; Nb+Ta commonly reported ≥99.8 % | balance | — |
R04210 Annealed — frequently asked
What is R04210 Annealed used for?
R04210 Annealed is typically used for chemical process vessels, superconducting RF components, electronic capacitor anodes and corrosion-resistant liners. In short: most formable refractory metal; baseline commercial niobium; excellent acid corrosion resistance.
What is the yield strength of R04210 Annealed?
R04210 Annealed has a typical yield strength of 115 MPa (16.7 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 100% of refractory metal grades. Strength varies by condition: see the 3 listed tempers.
Is R04210 Annealed easy to machine?
Not especially — machinability is rated poor (28/100, worse than 58% of refractory metal grades). Gummy and galling-prone: use sharp, positive-rake carbide or HSS tooling, slow speeds, heavy feeds, flood chlorinated or sulfurized coolant, and avoid dwelling to prevent smearing and work hardening.
Can R04210 Annealed be welded?
Yes — weldability is rated very good (70/100). GTAW/EBW/laser weld readily but must be done in a vacuum chamber or with complete trailing/backing inert gas — any O, N or H pickup above ~250 °C embrittles the weld; use Nb or Nb-1Zr filler.
What surface finishes work on R04210 Annealed?
Pickle in HF-HNO3 or buffered chemical polish, electropolish for SRF/UHV surfaces; anodizing gives decorative Nb2O5 interference colours; avoid iron contamination during grinding.
Can R04210 Annealed be formed, bent or molded?
Outstanding cold formability — deep drawing, spinning and >90 % cold rolling reduction are routine with intermediate vacuum anneals at 1100–1300 °C; use non-galling tooling coatings or lubricated interleaf.
What is the maximum service temperature of R04210 Annealed?
R04210 Annealed 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 R04210 Annealed and R04210-CW?
Annealed is the default condition — default stock condition for sheet, plate, rod and tube; maximum ductility for deep drawing, spinning and forming. CW: highest room-temperature strength for springs, fasteners and thin foil where no recrystallization anneal follows. Yield strength is 115 MPa in Annealed versus 420 MPa in CW.
Sources
- ASTM B393 — Niobium and Niobium Alloy Strip, Sheet, and Plate — ASTM International (2020)
- ASTM B392 — Niobium and Niobium Alloy Bar, Rod, and Wire — ASTM International (2020)
- ASTM B394 — Niobium and Niobium Alloy Seamless and Welded Tubes — ASTM International (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Refractory Metals) — ASM International (1990)
- CRC Handbook of Chemistry and Physics — Physical Properties of the Elements — CRC Press (2023)
- Commercially pure niobium (Nb1 / R04210) mill product datasheet — Refractory-metal producers (ATI / Plansee / ) (2023)
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.