Refractory Metal Chromium Alloy 33 SA-FRG
Heat-treated state
UNS R20033 · ASTM B615/B616/B617
SA-FRG = forged then solution annealed
Heavy sections and pressure fittings supplied to ASTM B564/B462-type requirements.
Values for the SA-FRG condition
Other Chromium Alloy 33 tempers and conditions
Chromium Alloy 33 is listed in 5 conditions; see the grade overview at Chromium Alloy 33.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SA-FRGThis page 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 SA-FRG?
Chromium Alloy 33 SA-FRG is Chromium Alloy 33 heat treated to SA-FRG — heavy sections and pressure fittings supplied to ASTM B564/B462-type requirements. Chromium Alloy 33 SA-FRG has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 64% of refractory metal grades. Elongation at break is 45% and the elastic modulus is 200 GPa (29 Msi). Chromium Alloy 33 SA-FRG 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). SA is the default condition FabDigit quotes; SA-FRG is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 45%, better than 99% 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 SA-FRG properties
Typical room-temperature values for Chromium Alloy 33 SA-FRG; 21 are specific to this condition. Other listed values are Chromium Alloy 33 reference data and may not represent this condition. Bars are the position among refractory metal grades.
Physical3
Chromium Alloy 33 SA-FRG 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 SA-FRG has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 64% of refractory metal grades. Elongation at break is 45% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
Chromium Alloy 33 SA-FRG 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 SA-FRG conducts electricity at 1.7 % IACS, worse than 93% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (87/100), better than 60% of refractory metal grades.
Sustainability4
Producing a kilogram of Chromium Alloy 33 SA-FRG 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 SA-FRG's machinability is poor (22/100, worse than 73% of refractory metal grades); weldability very good (72/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Chromium Alloy 33 SA-FRG
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.
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.
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) | — |
Chromium Alloy 33 SA-FRG — frequently asked
What is Chromium Alloy 33 SA-FRG used for?
Chromium Alloy 33 SA-FRG 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 SA-FRG?
Chromium Alloy 33 SA-FRG has a typical yield strength of 415 MPa (60.2 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 64% of refractory metal grades. Strength varies by condition: see the 5 listed tempers.
Is Chromium Alloy 33 SA-FRG 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 SA-FRG 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 SA-FRG?
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 SA-FRG 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 SA-FRG?
Chromium Alloy 33 SA-FRG 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.