Refractory Metal Chromium Alloy 33
UNS R20033 · ASTM B615/B616/B617
Chromium Alloy 33 (UNS R20033; ASTM B615/B616/B617) is a wrought high-chromium alloy with a high melting point, low density relative to other refractory metals, and good resistance to oxidation and molten-metal attack.
Reference datasheet — Chromium Alloy 33 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 SA condition
Chromium Alloy 33 tempers and conditions
Chromium Alloy 33 is supplied in 5 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Forged then solution annealed | Heavy sections and pressure fittings supplied to ASTM B564/B462-type requirements. | 415 | 780 | 45 | 195 HB | 1.7 % IACS |
SADefault Solution annealed | Standard stocked condition for plate, sheet, bar, pipe and tube; maximum corrosion resistance and ductility. | 430 | 810 | 50 | 200 HB | — |
Cold rolled and solution annealed sheet/strip | Thin sheet and strip for vessel linings, plate heat exchangers and bellows where surface finish matters. | 450 | 830 | 45 | 210 HB | 1.7 % IACS |
As-welded deposit | Property basis for weld joints and weld overlay when no post-weld solution anneal is applied. | 460 | 760 | 35 | 18 HRC | 1.6 % IACS |
Cold worked | Choose when higher proof strength and close dimensional tolerance are needed, e.g. fasteners and pump shafts. | 720 | 980 | 25 | 28 HRC | — |
What is Chromium Alloy 33?
Chromium Alloy 33 (UNS R20033; ASTM B615/B616/B617) is a wrought high-chromium alloy with a high melting point, low density relative to other refractory metals, and good resistance to oxidation and molten-metal attack. Solution-annealed and cold-worked bar, wire and forged stock combine 430 MPa yield, 810 MPa tensile and 50 % elongation with 200 HB (94 HRB) and a corrosion-resistance score of 88. Limits are a 450 °C maximum service temperature on file, low machinability (22) and rapid work hardening in forming, which requires roughly twice the press force of 304. Chromium Alloy 33 has a density of 7.9 g/cm³ (0.285 lb/in³), lighter than 51% of refractory metal grades. It melts at 1,350°C (2,462 °F). Chromium Alloy 33 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 810 MPa (117 ksi) — stronger than 66% of refractory metal grades. Elongation at break is 50% and the elastic modulus is 200 GPa (29 Msi).
What is Chromium Alloy 33 used for?
- high-temperature furnace parts
- glass and metal contact components
- electrical contact and resistor materials
- specialty alloying additive stock
Advantages
- Ductile — tolerates forming and impact — 50%, better than 100% of refractory metal grades
- Polishes to a fine finish — 80/100, better than 97% of refractory metal grades
- Low embodied carbon — 5.8 kg CO₂/kg, better than 97% of refractory metal grades
Limitations
- Poor heat conductor — 12 W/m·K (6.93 BTU/hr·ft·°F), worse than 98% of refractory metal grades
- Low electrical conductivity — 1.7 % IACS, worse than 93% of refractory metal grades
Chromium Alloy 33 properties
Typical room-temperature values for Chromium Alloy 33-SA; bars are the position among refractory metal grades.
Physical3
Chromium Alloy 33 has a density of 7.9 g/cm³ (0.285 lb/in³), lighter than 51% of refractory metal grades. It melts at 1,350°C (2,462 °F).
Mechanical13
Chromium Alloy 33 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 810 MPa (117 ksi) — stronger than 66% of refractory metal grades. Elongation at break is 50% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
Chromium Alloy 33 is rated for continuous service to 450°C (842 °F). It conducts heat at 12 W/m·K (6.93 BTU/hr·ft·°F), worse than 98% of refractory metal grades. Thermal expansion is 14.5 µm/m·K (8.06 µin/in·°F).
Electrical3
Chromium Alloy 33 conducts electricity at 1.7 % IACS, worse than 93% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 64% of refractory metal grades.
Sustainability4
Producing a kilogram of Chromium Alloy 33 takes about 78 MJ of energy and emits 5.8 kg of CO₂ — less than 96% of refractory metal grades. Typical recycled content is 35%.
Manufacturability8
Chromium Alloy 33's machinability is poor (22/100, worse than 73% of refractory metal grades); weldability very good (72/100); formability fair (50/100).
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. Chromium Alloy 33 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Chromium Alloy 33
Is Chromium Alloy 33 easy to machine?
Machine like a super-austenitic: rigid setups, sharp positive-rake carbide, ~25–50 % of 316L cutting speed, heavy feed to cut under the work-hardened layer, and flood coolant.
Can Chromium Alloy 33 be welded?
Weld with matching Alloy 33 filler (or over-alloyed Ni-base such as ERNiCrMo-3/-4), low heat input, interpass below ~150 °C, no preheat and no PWHT; backing gas with Ar+N₂ preserves nitrogen in root passes.
Can Chromium Alloy 33 be formed, bent or molded?
Cold forms well but work-hardens quickly and needs roughly twice the press force of 304; hot work 1100–1200 °C followed by solution anneal and water quench.
Chromium Alloy 33 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 |
|---|---|---|
| Crdrives PREN and nitric-acid resistance | 31 – 35 | 33 |
| Ni | 30 – 33 | 31 |
| Mo | 0.5 – 2 | 1.6 |
| Cuimproves sulphuric acid behaviour | 0.3 – 1.2 | 0.6 |
| Naustenite stabiliser, doubles proof strength | 0.35 – 0.6 | 0.45 |
| Mn | ≤ 2 | 0.5 |
| Si | ≤ 0.5 | 0.3 |
| C | ≤ 0.02 | 0.01 |
| P | ≤ 0.02 | |
| S | ≤ 0.01 | |
| Fe | ≥ 30 (balance) |
What surface finishes work on Chromium Alloy 33?
Pickle in HNO₃/HF then passivate to restore the Cr-rich film; mechanically polishes to a bright finish — never anodize, and avoid carbon-steel contamination during grinding.
Equivalent designations
Standards and trade names that resolve to Refractory Metal Chromium Alloy 33 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R20033
- ASTM
- B615/B616/B617
How much does Chromium Alloy 33 cost?
Chromium Alloy 33 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.
Chromium Alloy 33 — frequently asked
What is Chromium Alloy 33 used for?
Chromium Alloy 33 is typically used for high-temperature furnace parts, glass and metal contact components, electrical contact and resistor materials and specialty alloying additive stock. In short: ductile wrought chromium grade; corrosion-resistance score 88; weldable in the Cr-alloy family.
What is the yield strength of Chromium Alloy 33?
Chromium Alloy 33 has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 810 MPa (117 ksi) — stronger than 66% of refractory metal grades. Strength varies by condition: see the 5 listed tempers.
Is Chromium Alloy 33 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 73% of refractory metal grades). Machine like a super-austenitic: rigid setups, sharp positive-rake carbide, ~25–50 % of 316L cutting speed, heavy feed to cut under the work-hardened layer, and flood coolant.
Can Chromium Alloy 33 be welded?
Yes — weldability is rated very good (72/100). Weld with matching Alloy 33 filler (or over-alloyed Ni-base such as ERNiCrMo-3/-4), low heat input, interpass below ~150 °C, no preheat and no PWHT; backing gas with Ar+N₂ preserves nitrogen in root passes.
What surface finishes work on Chromium Alloy 33?
Pickle in HNO₃/HF then passivate to restore the Cr-rich film; mechanically polishes to a bright finish — never anodize, and avoid carbon-steel contamination during grinding.
Can Chromium Alloy 33 be formed, bent or molded?
Cold forms well but work-hardens quickly and needs roughly twice the press force of 304; hot work 1100–1200 °C followed by solution anneal and water quench.
What is the maximum service temperature of Chromium Alloy 33?
Chromium Alloy 33 is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Chromium Alloy 33-SA and Chromium Alloy 33-CW?
SA is the default condition — standard stocked condition for plate, sheet, bar, pipe and tube; maximum corrosion resistance and ductility. CW: choose when higher proof strength and close dimensional tolerance are needed, e.g. fasteners and pump shafts. Yield strength is 430 MPa in SA versus 720 MPa in CW.
How much does Chromium Alloy 33 cost?
Chromium Alloy 33 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
- VDM Alloy 33 / Nicrofer 3033 material data sheet — VDM Metals (2020)
- ASTM B625 — Cr-Ni-Fe-Mo-Cu-N alloy plate, sheet and strip (incl. UNS R20033) — ASTM International (2021)
- ASTM B649 — Ni-Fe-Cr-Mo-Cu alloy bar, wire and forgings — ASTM International (2021)
- ASTM B622 / B619 / B626 — seamless pipe & tube, welded pipe, welded tube — ASTM International (2021)
- EN 10088-2 — X1CrNiMoCuN33-32-1 (1.4591) — CEN (2014)
- ASM Handbook Vol. 13B — Corrosion: Materials — 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.