# Z2CND22.05AZ Forgings (AFNOR Duplex 2205 / UNS S31803 / EN 1.4462)

Source: https://www.steelforgepieces.com/Stainless-Steel/Z2CND22.05AZ.html
Supplier: Jiangyin Jiangnan Metal Co., Ltd., open-die forging works, Jiangyin, Jiangsu, China
Contact: +86 189-2135-9659 | sales@steelforgepieces.com
Updated: 11 October 2026

Z2CND22.05AZ is the French AFNOR designation for 22% chromium duplex stainless steel, the alloy sold elsewhere as duplex 2205, UNS S31803 and EN 1.4462. Jiangyin Jiangnan Metal Co., Ltd. melts and open-die forges this grade into rolled rings, flanges, shafts, round bars, discs, tube sheets, sleeves, bushings and valve parts, supplied solution annealed with EN 10204 3.1 or 3.2 certification.

## Data summary

| Item | Value |
|---|---|
| Designation | Z2CND22.05AZ (AFNOR); also Z3CND22-05AZ, Z2 CND 22.05 AZ |
| Alloy type | Nitrogen-alloyed ferritic-austenitic duplex stainless steel |
| UNS number | S31803 (closely related: S32205) |
| EN number / name | 1.4462 / X2CrNiMoN22-5-3 |
| Trade names | Duplex 2205, SAF 2205 |
| ASTM forging grade | A182 F51 (S31803); A182 F60 (S32205) |
| Nominal chemistry | 22% Cr, 5-6% Ni, 3% Mo, 0.08-0.20% N |
| Carbon | 0.030% max |
| Structure | Approximately 50:50 ferrite and austenite |
| 0.2% proof strength | 450 MPa min |
| Tensile strength | 650-880 MPa (EN 10088-3); 620 MPa min (ASTM A182 F51) |
| Elongation | 25% min |
| Hardness | 270 HB max (EN 10088-3); 293 HBW max (ASTM A182 F51) |
| PREN | 33-36 |
| Heat treatment | Solution anneal 1020-1100 °C, water quench |
| Magnetic | Yes, from the ferrite phase |

## What the grade is

The designation breaks down element by element. Z marks a high-alloy steel, 2 is the carbon content in hundredths of a percent, C, N and D are the French symbols for chrome, nickel and molybdène, 22.05 gives approximate chromium and nickel levels, and AZ marks the low-carbon nitrogen-alloyed variant.

The structure is roughly half ferrite and half austenite. Proof strength is about double that of austenitic 316 at similar or lower nickel content, with far better resistance to chloride stress corrosion cracking and pitting.

Carbon is 0.030% max, not 0.30%. Carbon above 0.03% would sensitise the steel during welding and remove the intergranular corrosion resistance the alloy is bought for.

## Equivalent grades

| Standard / country | Designation | Notes |
|---|---|---|
| AFNOR, France | Z2CND22.05AZ / Z3CND22-05AZ | The designation on this page |
| EN 10088, Europe | 1.4462, X2CrNiMoN22-5-3 | Reference European duplex grade |
| UNS, USA | S31803 | Cr 21.0-23.0, N 0.08-0.20 |
| UNS, USA | S32205 | Tighter: Cr 22.0-23.0, Mo 3.0-3.5, N 0.14-0.20 |
| ASTM / ASME forgings | A182 F51 (S31803), A182 F60 (S32205) | |
| ISO | CrNiMo22-5-3 | Matches EN 1.4462 |
| BS, UK | 318S13 | P limited to 0.025 |
| JIS, Japan | SUS 329J3L | Cr 21.0-24.0 |
| GOST, Russia | 02Ch22N5M3 / 022253 | Matches 1.4462 |
| Producer names | SAF 2205, Duplex 2205 | Typical aim 22Cr-3.2Mo-5Ni-0.18N |

These grades are equivalent, not identical. Silicon, phosphorus and sulphur limits differ between standards, and S32205 is tighter than S31803.

## Chemical composition, weight %

| Element | AFNOR Z3CND22-05AZ | EN 1.4462 | UNS S31803 |
|---|---|---|---|
| C | 0.030 max | 0.030 max | 0.030 max |
| Si | 0.75 max | 1.00 max | 1.00 max |
| Mn | 2.00 max | 2.00 max | 2.00 max |
| P | 0.035 max | 0.030 max | 0.030 max |
| S | 0.010 max | 0.020 max | 0.020 max |
| Cr | 21.0-23.0 | 21.0-23.0 | 21.0-23.0 |
| Ni | 4.50-6.50 | 4.50-6.50 | 4.50-6.50 |
| Mo | 2.50-3.50 | 2.50-3.50 | 2.50-3.50 |
| N | 0.08-0.20 | 0.08-0.20 | 0.08-0.20 |
| Fe | Balance | Balance | Balance |

PREN is normally Cr% + 3.3 × Mo% + 16 × N%, giving 33-36 for typical 2205 chemistry. Published tables list S31803 at about 36, and PREN above 34 is commonly offered by agreement. The 30 × N variant returns a higher figure near 38.

## Mechanical properties, solution annealed

| Property | EN 10088-3 (1.4462) | ASTM A182 F51 (S31803) |
|---|---|---|
| Tensile strength | 650-880 MPa | 620 MPa min |
| 0.2% proof strength | 450 MPa min | 450 MPa min |
| Elongation | 25% min | 25% min |
| Hardness, max | 270 HB | 293 HBW (31 HRC) |
| Impact energy | 100 J | Charpy V-notch, set of three per heat |
| Ferrite content | Nominally 50% | 40-60% |

EN 10088-3 figures apply to solution-treated bar up to 160 mm diameter. Heavy sections are verified on a test piece representing the delivered thickness.

## Physical properties at 20 °C, typical for 1.4462

Density 7.8 g/cm³. Modulus of elasticity 200 GPa. Thermal conductivity 15 W/m·K. Specific heat 500 J/kg·K. Thermal expansion 13.0 × 10⁻⁶ /K over 20-100 °C. Electrical resistivity 0.80 Ω·mm²/m. Ferromagnetic.

## Service temperature and corrosion

European practice caps continuous service at about 200-250 °C; ASTM-oriented guidance for F51 cites approximately 315 °C (600 °F). Longer exposure in that range precipitates sigma and other embrittling phases.

The grade resists intergranular corrosion, pitting and crevice attack, and its main advantage over 304 and 316 is resistance to chloride stress corrosion cracking. Published data for 1.4462 shows it holding up in concentrated calcium, lithium and sodium chloride solutions at raised temperature, where austenitic grades crack. For warm seawater or severely sour duty, move up to A182 F53 or F55.

## Forging and heat treatment

Parts are hot forged near to finished shape, cooled below about 540 °C, then solution annealed at 1020-1100 °C and water quenched. The quench must be fast enough to suppress sigma phase, so section thickness, transfer time and quench capacity matter on heavy rings, tube sheets and shafts. Fourteen heat-treatment furnaces serve the forge line.

Duplex grades are melted in the electric arc furnace, refined in the ladle furnace and decarburised under vacuum, which delivers both the low carbon and the controlled nitrogen. Heats run to 60 tonnes, and electroslag remelting is available.

Machining: the grade work hardens quickly. Use coated cemented carbide, rigid setups, well-reduced cutting speed and plenty of coolant. Reduce feed only slightly, since too light a feed glazes the surface and shortens tool life.

## Product forms

Seamless rolled rings to 6,000 mm outside diameter. Forged rings. Forged flanges to ASME B16.5, B16.47, EN 1092-1 and API 6A. Shafts, spindles and crankshafts. Discs, tube sheets and covers. Round, flat and square bar. Sleeves, bushings, cylinders and forged pipe. Valve and wellhead parts including bodies, bonnets, seat rings, stems, blocks, spools and nozzles.

## Applications

Offshore and subsea oil and gas hardware, wellheads, Christmas trees, manifolds, spools and downhole components for moderately sour wells. Seawater and desalination service, firewater and cooling systems, reverse osmosis connections, separator and heat exchanger parts. Chemical and petrochemical plant for brine and chloride-bearing acid duty, crystalliser equipment and reactor nozzles. Pulp and paper digesters, liquor tanks, machine rolls and shafts. Turbine and gas compressor parts, gearboxes, air compressors and nitrogen generators. Shipbuilding components, forged rolls, wheels and pressure vessel sections.

## Testing and certification

Chemical analysis to ASTM E415 and E1019, plus PMI. Tension testing to ASTM A370 or ISO 6892. Charpy V-notch impact testing to -60 °C in house. Intermetallic phase checks to ASTM A923 Methods A, B and C and ASTM A1084. Ferrite content 40-60% by metallography or magnetic method. Intergranular corrosion to ASTM A262 and G28. Pitting to ASTM G48. Ultrasonic testing to ASTM A388, EN 10228-3 and SEP 1921. Magnetic particle to ASTM E709 and liquid penetrant.

Certification is EN 10204 3.1 as standard, or EN 10204 3.2 witnessed by BV, DNV, LR, SGS, TÜV or your own inspector. The works holds CCS, BV, DNV, LR and NK approvals.

## Frequently asked questions

**What is Z2CND22.05AZ equivalent to?**
The French AFNOR designation for 22Cr duplex stainless steel, cross-referenced to EN 1.4462 (X2CrNiMoN22-5-3), UNS S31803 and the closely related UNS S32205, ISO CrNiMo22-5-3, BS 318S13, JIS SUS 329J3L, GOST 02Ch22N5M3, and the trade names duplex 2205 and SAF 2205. For forgings the ASTM designation is A182 F51 for S31803 and A182 F60 for S32205.

**What is the carbon content?**
0.030% maximum. A figure of 0.30% in any listing is a misplaced decimal point.

**What heat treatment does it need?**
Solution annealing at 1020-1100 °C followed by a water quench, rapid enough to prevent sigma phase precipitation.

**Is it magnetic?**
Yes. About half the structure is ferrite, so duplex stainless steels are ferromagnetic, unlike 304 and 316.

**What is the maximum service temperature?**
About 200-250 °C in European practice, or approximately 315 °C under ASTM-oriented guidance for F51. Above that the duplex structure embrittles.

**How does it compare with 316?**
Roughly double the minimum proof strength, 450 MPa against 205 MPa for F316, a PREN near 35 against about 26, and much better chloride stress corrosion cracking resistance. Against that, higher alloy cost, a lower temperature ceiling and more demanding machining.

**Can it be used in sour service to NACE MR0175?**
In moderately sour service where the hardness limit of the applicable NACE MR0175 and ISO 15156 material data sheet is met, commonly below 28 HRC, together with the stated environmental limits.

**Do you melt your own steel?**
Yes. Duplex grades run through the electric arc furnace, ladle furnace and vacuum oxygen decarburisation, with electroslag remelting available and heats up to 60 tonnes. The certificate traces the forging to its melt number.

## Requesting a quotation

Include: grade and governing standard; dimensions or drawing in PDF, DWG, DXF or STEP; quantity and repeat volume; delivery condition; heat treatment and testing requirements; certification and destination port.

Email sales@steelforgepieces.com or call +86 189-2135-9659.

## Company

Jiangyin Jiangnan Metal Co., Ltd.
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone +86 189-2135-9659 | Email sales@steelforgepieces.com | https://www.steelforgepieces.com/

Integrated steel melting and open-die forging works operating since 1997. 460 employees including 9 senior engineers, 32 intermediate engineers and 140 technicians. Melting, forging, ring rolling, heat treatment, machining and testing on one site. Classification society approvals CCS, BV, DNV, LR and NK. Exports to North America, Europe, the Middle East and Asia-Pacific.