Refractory Metal 50Cr-50Ni-Cb
UNS R20501 · ASTM A560 Gr 50Cr-50Ni-Cb
50Cr-50Ni-Cb (UNS R20501, ASTM A560) is a niobium (columbium)-stabilised 50 % chromium–50 % nickel cast alloy; the Nb addition raises creep strength and stabilises grain boundaries under thermal cycling.
Reference datasheet — 50Cr-50Ni-Cb is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the AC condition
50Cr-50Ni-Cb tempers and conditions
50Cr-50Ni-Cb is supplied in 4 conditions, soft to hard. AC is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As-cast plus stress relief | Choose when castings are heavily welded or machined and residual stress could cause distortion or cracking on first heat-up. | 370 | 570 | 9 | 205 HB | 1.6 % IACS |
As-welded deposit | Condition of weld repairs and of protective weld overlays applied to cheaper substrates in boiler fuel-ash zones. | 380 | 560 | 5 | 19 HRC | 1.6 % IACS |
ACDefault Spheroidize annealed | Standard supply condition for sand/investment castings — tube supports, hangers, burner parts for fuel-ash corrosion service. | 390 | 590 | 8 | 16 HRC | 1.6 % IACS |
Hot isostatic pressed | Specify for critical, thermally cycled or pressure-containing castings where shrinkage porosity must be closed to raise ductility and creep life. | 400 | 630 | 12 | 16 HRC | 1.6 % IACS |
What is 50Cr-50Ni-Cb?
50Cr-50Ni-Cb (UNS R20501, ASTM A560) is a niobium (columbium)-stabilised 50 % chromium–50 % nickel cast alloy; the Nb addition raises creep strength and stabilises grain boundaries under thermal cycling. It is supplied as sand or investment castings for furnace hardware serving to about 1100 °C, with 390 MPa yield, 590 MPa tensile, 8 % elongation and 210 HB in the as-cast condition. The duplex structure is brittle at room temperature, abrasive to machine (machinability 12) and hot-crack sensitive, so aged parts are rarely weld-repaired. Unstabilised 50Cr-50Ni is the alternative where creep loads are lower. 50Cr-50Ni-Cb has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 54% of refractory metal grades. It melts at 1,370°C (2,498 °F). 50Cr-50Ni-Cb has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 590 MPa (85.6 ksi) — stronger than 61% of refractory metal grades. Elongation at break is 8% and the elastic modulus is 190 GPa (27.6 Msi).
What is 50Cr-50Ni-Cb used for?
- furnace muffles and retorts
- heat-treat baskets
- high-temperature fixturing
- carburizing/nitriding equipment
Advantages
- Low embodied carbon — 10.5 kg CO₂/kg, better than 88% of refractory metal grades
Limitations
- Hard to polish — 45/100, worse than 98% of refractory metal grades
- Low electrical conductivity — 1.6 % IACS, worse than 96% of refractory metal grades
- Poor heat conductor — 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 90% of refractory metal grades
- Limited formability — 8/100, worse than 90% of refractory metal grades
- Difficult to machine — 12/100, worse than 86% of refractory metal grades
50Cr-50Ni-Cb properties
Typical room-temperature values for 50Cr-50Ni-Cb-AC; bars are the position among refractory metal grades.
Physical3
50Cr-50Ni-Cb has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 54% of refractory metal grades. It melts at 1,370°C (2,498 °F).
Mechanical17
50Cr-50Ni-Cb has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 590 MPa (85.6 ksi) — stronger than 61% of refractory metal grades. Elongation at break is 8% and the elastic modulus is 190 GPa (27.6 Msi).
Thermal6
50Cr-50Ni-Cb is rated for continuous service to 1,100°C (2,012 °F). It conducts heat at 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 90% of refractory metal grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
50Cr-50Ni-Cb conducts electricity at 1.6 % IACS, worse than 96% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 64% of refractory metal grades.
Sustainability4
Producing a kilogram of 50Cr-50Ni-Cb takes about 135 MJ of energy and emits 10.5 kg of CO₂ — less than 91% of refractory metal grades. Typical recycled content is 30%.
Manufacturability8
50Cr-50Ni-Cb's machinability is not recommended (12/100, worse than 86% of refractory metal grades); weldability poor (25/100); formability not recommended (8/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the refractory metal family
Yield strength against density for every refractory metal grade FabDigit runs. 50Cr-50Ni-Cb is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 50Cr-50Ni-Cb
Is 50Cr-50Ni-Cb easy to machine?
Very difficult and abrasive — use rigid setups, ceramic or coated-carbide inserts, low speed with heavy positive feed, flood coolant; grinding or EDM for finish features on hard duplex structure.
Can 50Cr-50Ni-Cb be welded?
GTAW/SMAW with matching 50Cr-50Ni-Nb filler only, low heat input, interpass temperature control and minimal restraint; highly sensitive to hot cracking and post-service embrittlement, so field repair of aged parts is generally not recommended.
Can 50Cr-50Ni-Cb be formed, bent or molded?
Not cold formable — parts are produced as sand or investment castings (air or vacuum melt); allow generous fillets and controlled solidification to avoid shrinkage porosity.
50Cr-50Ni-Cb 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 |
|---|---|---|
| Crduplex Cr-rich α phase former; source of fuel-ash resistance | 48 – 52 | 50 |
| Nbcolumbium (Cb) — carbide/grain-boundary stabilizer, creep strength | 1 – 2 | 1.5 |
| C | ≤ 0.1 | 0.06 |
| Si | ≤ 0.5 | 0.3 |
| Mn | ≤ 0.3 | 0.15 |
| Ti | ≤ 0.5 | 0.2 |
| Al | ≤ 0.25 | 0.1 |
| Fe | ≤ 1 | 0.5 |
| S | ≤ 0.02 | |
| P | ≤ 0.02 | |
| Nibalance, nominally ~46–48 % | balance |
What surface finishes work on 50Cr-50Ni-Cb?
Service protection comes from the self-forming Cr₂O₃ scale; shot blast or pickle to remove casting scale, no plating or anodizing needed and paint is pointless at service temperature.
Equivalent designations
Standards and trade names that resolve to Refractory Metal 50Cr-50Ni-Cb in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R20501
- ASTM
- A560 Gr 50Cr-50Ni-Cb
How much does 50Cr-50Ni-Cb cost?
50Cr-50Ni-Cb is a high-cost refractory metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
50Cr-50Ni-Cb — frequently asked
What is 50Cr-50Ni-Cb used for?
50Cr-50Ni-Cb is typically used for furnace muffles and retorts, heat-treat baskets, high-temperature fixturing and carburizing/nitriding equipment. In short: creep-stabilised 50/50 casting; thermal-cycling furnace grade; cast-only, not formable.
What is the yield strength of 50Cr-50Ni-Cb?
50Cr-50Ni-Cb has a typical yield strength of 390 MPa (56.6 ksi) and a tensile strength of 590 MPa (85.6 ksi) — stronger than 61% of refractory metal grades. Strength varies by condition: see the 4 listed tempers.
Is 50Cr-50Ni-Cb easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 86% of refractory metal grades). Very difficult and abrasive — use rigid setups, ceramic or coated-carbide inserts, low speed with heavy positive feed, flood coolant; grinding or EDM for finish features on hard duplex structure.
Can 50Cr-50Ni-Cb be welded?
Not readily — weldability is rated poor (25/100). GTAW/SMAW with matching 50Cr-50Ni-Nb filler only, low heat input, interpass temperature control and minimal restraint; highly sensitive to hot cracking and post-service embrittlement, so field repair of aged parts is generally not recommended.
What surface finishes work on 50Cr-50Ni-Cb?
Service protection comes from the self-forming Cr₂O₃ scale; shot blast or pickle to remove casting scale, no plating or anodizing needed and paint is pointless at service temperature.
Can 50Cr-50Ni-Cb be formed, bent or molded?
Not cold formable — parts are produced as sand or investment castings (air or vacuum melt); allow generous fillets and controlled solidification to avoid shrinkage porosity.
What is the maximum service temperature of 50Cr-50Ni-Cb?
50Cr-50Ni-Cb is rated for continuous use to about 1,100°C (2,012 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 50Cr-50Ni-Cb-AC and 50Cr-50Ni-Cb-HIP?
AC is the default condition — standard supply condition for sand/investment castings — tube supports, hangers, burner parts for fuel-ash corrosion service. HIP: specify for critical, thermally cycled or pressure-containing castings where shrinkage porosity must be closed to raise ductility and creep life. Yield strength is 390 MPa in AC versus 400 MPa in HIP.
How much does 50Cr-50Ni-Cb cost?
50Cr-50Ni-Cb is a high-cost refractory metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM A560/A560M — Castings, Chromium-Nickel Alloy — ASTM International (2020)
- IN-657 (50Cr-50Ni-Nb) alloy data for fuel-ash corrosion resistance — Special Metals / Inco-type producer literature (2004)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (high-temperature fuel-ash corrosion) — ASM International (2005)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.