Stainless Steel 20Cb-3 · temper
Stainless Steel 20Cb-3 Annealed
Properties of the Annealed condition, compared with the other 20Cb-3 tempers.
Pick for hot-finished bar, forgings and heavy sections where softest, most ductile condition is wanted for further forming or welding.
What is 20Cb-3 Annealed?
20Cb-3 Annealed is 20Cb-3 in the Annealed temper — pick for hot-finished bar, forgings and heavy sections where softest, most ductile condition is wanted for further forming or welding. 20Cb-3 Annealed has a yield strength of 310 MPa (45 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 63% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 193 GPa (28 Msi). 20Cb-3 Annealed has a density of 8.08 g/cm³ (0.292 lb/in³), heavier than 99% of stainless steel grades. It melts at 1,425°C (2,597 °F). Solution Annealed is the default condition FabDigit quotes; Annealed is available on request or by drawing note.
Advantages
- Forms and bends easily — 72/100, better than 83% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- Low electrical conductivity — 1.6 % IACS, worse than 99% of stainless steel grades
- High embodied carbon — 7.5 kg CO₂/kg, worse than 97% of stainless steel grades
- Poor heat conductor — 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 87% of stainless steel grades
20Cb-3 Annealed properties
Typical room-temperature values for 20Cb-3 Annealed — 10 properties are specific to this condition; the rest are grade-level values shared by every 20Cb-3 temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
20Cb-3 Annealed has a density of 8.08 g/cm³ (0.292 lb/in³), heavier than 99% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical14
20Cb-3 Annealed has a yield strength of 310 MPa (45 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 63% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 193 GPa (28 Msi).
Thermal5
20Cb-3 Annealed is rated for continuous service to 500°C (932 °F). It conducts heat at 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 87% of stainless steel grades. Thermal expansion is 14.8 µm/m·K (8.22 µin/in·°F).
Electrical3
20Cb-3 Annealed conducts electricity at 1.6 % IACS, worse than 99% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), better than 74% of stainless steel grades.
Sustainability4
Producing a kilogram of 20Cb-3 Annealed takes about 110 MJ of energy and emits 7.5 kg of CO₂ — more than 99% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
20Cb-3 Annealed's machinability is poor (33/100, worse than 57% of stainless steel grades); weldability very good (75/100); formability very good (72/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 20Cb-3 tempers and conditions
20Cb-3 is also supplied in 3 other conditions. The full side-by-side table is on the 20Cb-3 overview.
- Solution AnnealedDefaultStandard as-supplied condition for plate, sheet, pipe and fittings; maximum corrosion resistance and ductility.345 MPa yield · 160 HB
- Cold Drawn Hard WireUse only for wire, springs and cold-headed parts needing maximum strength; heavy cold work raises hardness and slightly lowers corrosion margin.900 MPa yield · 35 HRC
- Cold DrawnChoose for higher-strength bar, shafting and fasteners where tight tolerance and better surface are needed; ductility and formability are reduced.620 MPa yield · 24 HRC
- AnnealedPick for hot-finished bar, forgings and heavy sections where softest, most ductile condition is wanted for further forming or welding.310 MPa yield · 150 HB
Working with 20Cb-3 Annealed
Is 20Cb-3 easy to machine?
Gummy and strongly work-hardening — use rigid setups, positive-rake carbide, heavy feeds with slow speeds (~25–40% of 1212 rates), never dwell, and flood with chlorine-free coolant.
Can 20Cb-3 be welded?
Readily welded by GTAW/GMAW/SMAW with over-alloyed Nb-bearing filler (ER320LR / E320LR); keep interpass temperature low, no preheat, avoid excessive heat input and post-weld sensitizing exposure.
Can 20Cb-3 be formed, bent or molded?
Cold forms like a tough austenitic — allow 2–3× the power of carbon steel, generous bend radii and interstage anneals at 925–1010 °C with rapid cooling; hot work 1150–1200 °C, finish above 925 °C.
What surface finishes work on 20Cb-3?
Pickle and passivate (nitric-based) after welding or hot work to restore the passive film; polishes to a bright finish, cannot be anodized, and electroplating is only needed for special wear applications.
20Cb-3 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 |
|---|---|---|
| Ni | 32 – 38 | 34 |
| Cr | 19 – 21 | 20 |
| Mo | 2 – 3 | 2.5 |
| Cu | 3 – 4 | 3.5 |
| NbCb+Ta ≥ 8 × C (stabilizing); typically 0.3–1.0 % | ≈ 0.5 | 0.5 |
| C | ≤ 0.07 | 0.03 |
| Mn | ≤ 2 | 0.5 |
| Si | ≤ 1 | 0.5 |
| P | ≤ 0.05 | — |
| S | ≤ 0.04 | — |
| Febalance, nominally ~37 % | balance | — |
20Cb-3 Annealed — frequently asked
What is 20Cb-3 Annealed used for?
20Cb-3 Annealed is typically used for sulfuric acid pumps, pickling baths and tanks, chemical process piping and fittings, heat exchanger tubing and tubesheets, valve bodies and pump impellers and agitator shafts and mixing blades. In short: sulfuric-acid-resistant austenitic stainless.
What is the yield strength of 20Cb-3 Annealed?
20Cb-3 Annealed has a typical yield strength of 310 MPa (45 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 63% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 20Cb-3 Annealed easy to machine?
Not especially — machinability is rated poor (33/100, worse than 57% of stainless steel grades). Gummy and strongly work-hardening — use rigid setups, positive-rake carbide, heavy feeds with slow speeds (~25–40% of 1212 rates), never dwell, and flood with chlorine-free coolant.
Can 20Cb-3 Annealed be welded?
Yes — weldability is rated very good (75/100). Readily welded by GTAW/GMAW/SMAW with over-alloyed Nb-bearing filler (ER320LR / E320LR); keep interpass temperature low, no preheat, avoid excessive heat input and post-weld sensitizing exposure.
What surface finishes work on 20Cb-3 Annealed?
Pickle and passivate (nitric-based) after welding or hot work to restore the passive film; polishes to a bright finish, cannot be anodized, and electroplating is only needed for special wear applications.
Can 20Cb-3 Annealed be formed, bent or molded?
Cold forms like a tough austenitic — allow 2–3× the power of carbon steel, generous bend radii and interstage anneals at 925–1010 °C with rapid cooling; hot work 1150–1200 °C, finish above 925 °C.
What is the maximum service temperature of 20Cb-3 Annealed?
20Cb-3 Annealed is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 20Cb-3 Annealed?
Yes — 20Cb-3 Annealed is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B463 — Alloy N08020 Plate, Sheet and Strip — ASTM International (2020)
- ASTM B473 — UNS N08020 Bar and Wire — ASTM International (2020)
- ASTM B464/B729 — N08020 Welded and Seamless Pipe — ASTM International (2020)
- Carpenter 20Cb-3 Stainless Alloy Technical Datasheet — Carpenter Technology (2020)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Corrosion data for Fe-Ni-Cr-Mo-Cu alloys in sulfuric acid — NACE/AMPP compilations (2018)
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.