Stainless Steel R20033
UNS R20033 · ASTM B912 · EN X1NiCrMoCuN32-28-7
An extremely high-chromium (33%) superaustenitic stainless with outstanding resistance to a wide range of oxidizing and reducing acids, including hot sulfuric, phosphoric, and nitric mixtures; used where standard superaustenitics fall short.
Reference datasheet — R20033 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 Annealed condition
R20033 tempers and conditions
R20033 is supplied in 5 conditions, soft to hard. Annealed 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 + Annealed | Valve bodies, flanges and fittings; always re-annealed after forging to dissolve intermetallics and restore corrosion resistance. | 420 | 780 | 42 | 195 HB | 1.9 % IACS |
AnnealedDefault solution annealed and quenched (plate, sheet, bar, tube) | Standard delivery condition for all corrosion-service product forms; maximum corrosion resistance and ductility. | 430 | 800 | 45 | 200 HB | 1.9 % IACS |
As-welded deposit | Fabricated weldment condition; matching filler keeps N and Cr high so weld metal corrosion performance is close to base metal. | 450 | 760 | 30 | 210 HB | 1.9 % IACS |
Cold drawn | Pick for bar and small tubing where tighter tolerance, straightness and higher yield strength are wanted. | 620 | 900 | 28 | 25 HRC | 1.9 % IACS |
Cold rolled strip, hard temper | Thin strip/spring-type applications needing maximum strength; corrosion service still good but formability is minimal. | 800 | 1,050 | 12 | 32 HRC | 1.9 % IACS |
What is R20033?
An extremely high-chromium (33%) superaustenitic stainless with outstanding resistance to a wide range of oxidizing and reducing acids, including hot sulfuric, phosphoric, and nitric mixtures; used where standard superaustenitics fall short. R20033 has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F). R20033 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 67% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
What is R20033 used for?
- phosphoric and sulfuric acid production
- sour gas and oilfield equipment
- chemical process reactors
- flue gas desulfurization
Advantages
- Good corrosion resistance — 92/100, better than 99% of stainless steel grades
- Tough — resists crack growth — 200 MPa·√m (182 ksi·√in), better than 86% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- Poor heat conductor — 12 W/m·K (6.93 BTU/hr·ft·°F), worse than 93% of stainless steel grades
- Difficult to machine — 25/100, worse than 88% of stainless steel grades
- High embodied carbon — 6 kg CO₂/kg, worse than 88% of stainless steel grades
- Low electrical conductivity — 1.9 % IACS, worse than 84% of stainless steel grades
R20033 properties
Typical room-temperature values for R20033-Annealed; bars are the position among stainless steel grades.
Physical3
R20033 has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
R20033 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 67% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal6
R20033 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 93% of stainless steel grades. Thermal expansion is 14.5 µm/m·K (8.06 µin/in·°F).
Electrical3
R20033 conducts electricity at 1.9 % IACS, worse than 84% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 99% of stainless steel grades.
Sustainability4
Producing a kilogram of R20033 takes about 85 MJ of energy and emits 6 kg of CO₂ — more than 92% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
R20033's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability very good (70/100); formability good (60/100).
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 stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. R20033 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with R20033
Is R20033 easy to machine?
Machine like a superaustenitic/nickel alloy: rigid setup, positive-rake sharp carbide, low speed with heavy positive feed, flood coolant, and never dwell — the high-N austenite work-hardens fast and gums up.
Can R20033 be welded?
GTAW/GMAW/PAW with matching Alloy 33 (or overalloyed Ni-Cr-Mo) filler, low heat input, no preheat, interpass below ~150 °C; avoid autogenous welds losing N and avoid slow cooling through 700–900 °C.
Can R20033 be formed, bent or molded?
Excellent cold ductility but forming loads roughly double those of 316L; hot work 1100–1200 °C followed by mandatory solution anneal ~1080–1150 °C and rapid quench.
R20033 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 |
|---|---|---|
| Cr | 31 – 35 | 33 |
| Ni | 30 – 33 | 31 |
| Mo | 0.5 – 2 | 1.6 |
| Cu | 0.3 – 1.2 | 0.6 |
| Nnitrogen strengthening + pitting resistance | 0.35 – 0.6 | 0.45 |
| C | ≤ 0.02 | 0.01 |
| Mn | ≤ 2 | 0.5 |
| Si | ≤ 0.5 | 0.3 |
| P | ≤ 0.03 | |
| S | ≤ 0.01 | |
| Febalance, typically 30–33 % | balance |
What surface finishes work on R20033?
Pickle in HNO3-HF or electropolish to remove weld scale, then passivate in nitric acid; polishes to bright mirror finish and takes no anodize (not aluminium).
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel R20033 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B912
- EN / DIN / Werkstoff-Nr.
- X1NiCrMoCuN32-28-7
How much does R20033 cost?
R20033 is a high-cost stainless steel ($$$$), 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.
R20033 — frequently asked
What is R20033 used for?
R20033 is typically used for phosphoric and sulfuric acid production, sour gas and oilfield equipment, chemical process reactors and flue gas desulfurization. In short: 33% Cr acid-service austenitic; beyond 6% Mo grades; oxidizing and reducing acids.
What is the yield strength of R20033?
R20033 has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 800 MPa (116 ksi) — stronger than 67% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is R20033 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Machine like a superaustenitic/nickel alloy: rigid setup, positive-rake sharp carbide, low speed with heavy positive feed, flood coolant, and never dwell — the high-N austenite work-hardens fast and gums up.
Can R20033 be welded?
Yes — weldability is rated very good (70/100). GTAW/GMAW/PAW with matching Alloy 33 (or overalloyed Ni-Cr-Mo) filler, low heat input, no preheat, interpass below ~150 °C; avoid autogenous welds losing N and avoid slow cooling through 700–900 °C.
What surface finishes work on R20033?
Pickle in HNO3-HF or electropolish to remove weld scale, then passivate in nitric acid; polishes to bright mirror finish and takes no anodize (not aluminium).
Can R20033 be formed, bent or molded?
Excellent cold ductility but forming loads roughly double those of 316L; hot work 1100–1200 °C followed by mandatory solution anneal ~1080–1150 °C and rapid quench.
What is the maximum service temperature of R20033?
R20033 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 R20033 Annealed and R20033 CR-Hard?
Annealed is the default condition — standard delivery condition for all corrosion-service product forms; maximum corrosion resistance and ductility. CR-Hard: thin strip/spring-type applications needing maximum strength; corrosion service still good but formability is minimal. Yield strength is 430 MPa in Annealed versus 800 MPa in CR-Hard.
How much does R20033 cost?
R20033 is a high-cost stainless steel ($$$$), 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 — Ni-Fe-Cr-Mo alloy plate, sheet and strip (UNS R20033) — ASTM International (2020)
- ASTM B649 — Ni-Fe-Cr-Mo-Cu alloy bar and wire — ASTM International (2021)
- EN 10088-2 / EN 10028-7 — X1NiCrMoCuN32-28-7 (1.4591) — CEN (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
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.