Seamless rolled rings
Ring-rolled from a punched preform on a radial-axial mill. Rectangular or contoured section, for bearings, gears, flange blanks, wind-turbine and pressure-vessel service.
What 1.4462 is, and why the duplex structure matters
1.4462 is a duplex stainless steel: a single alloy that solidifies into two coexisting phases in roughly equal proportion. Ferrite carries the strength and the resistance to chloride stress-corrosion cracking; austenite carries the toughness and the ductility. Neither family gets both on its own, and that combination is the reason duplex is specified.
Against austenitic 316L, the practical differences are these. The 0.2 % proof strength is 450 MPa minimum instead of about 170 MPa, roughly 2.6 times, so a pressure-retaining part can be designed thinner for the same rating. Nickel content is around 5 % instead of 10–14 %, which makes the alloy less exposed to nickel price swings. Resistance to chloride stress-corrosion cracking, the failure mode that limits 304 and 316 in warm seawater, is far higher.
The trade-offs are equally real. 1.4462 is ferromagnetic, because ferrite is. It is difficult to machine (see §09). It must not be held between roughly 300 °C and 1,000 °C, because intermetallic phases form there and destroy both toughness and corrosion resistance. And because the phase balance is the property, every thermal step after forging has to be controlled and then proved by test.
Note on heat treatment
A duplex forging is not finished when it leaves the press. The 50:50 phase balance is created by the solution anneal and quench, not by the forging. A 1.4462 part that has been forged correctly but annealed poorly, or quenched too slowly through the 950–600 °C range, can meet its chemistry certificate and still fail an ASTM A923 test. It is a common cause of rejected duplex forgings.
Designations and equivalent grades
The same steel is ordered under at least a dozen names. The table below maps them. Where a standard covers a slightly different composition window rather than a true equivalent, that is stated. An approximate equivalent is not a substitution, and any swap needs the buyer's written agreement.
| System / country | Designation | Note |
|---|---|---|
| EN (number) | 1.4462 | Primary reference on this page |
| EN (name) | X2CrNiMoN22-5-3 | EN 10088-1 chemical designation |
| UNS | S31803 | Original, wider composition window |
| UNS | S32205 | Narrowed window; higher guaranteed PREN |
| ASTM / ASME forgings | A182 F51 · SA-182 F51 | Forged flanges, fittings, valves (S31803) |
| ASTM / ASME forgings | A182 F60 · SA-182 F60 | Same product forms, S32205 chemistry |
| AISI / SAE | 318LN | Common trade shorthand |
| AFNOR (France) | Z3CND22-05Az | Equivalent |
| BS (UK) | 318S13 | Equivalent |
| JIS (Japan) | SUS329J3L | Equivalent |
| GB/T 20878 (China) | 022Cr22Ni5Mo3N (S22253) | Corresponds to S31803 |
| GB/T 20878 (China) | 022Cr23Ni5Mo3N (S22053) | Corresponds to S32205 |
| Trade names | 2205 · SAF 2205 · Alloy 2205 · UR 2205 | Proprietary names for the same alloy family |
| Cast equivalent | 1.4470 · ASTM A995 Gr 4A (CD3MN) | Cast grade, not interchangeable with wrought 1.4462 |
F51 or F60? The distinction that decides an order
S31803 and S32205 are frequently treated as the same grade, and a mill certificate that says "S31803 / S32205 dual certified" is common. The difference is real and worth understanding before an enquiry is sent.
S31803 was specified with a wide composition window: chromium 21.0–23.0 %, molybdenum 2.5–3.5 %, nitrogen 0.08–0.20 %. A heat sitting at the bottom of that window is a legitimate S31803 and reaches a PREN of only about 30.5, well below the value of 35 that offshore and chloride-service specifications typically demand. S32205 was introduced to close that gap, tightening the same alloy to chromium 22.0–23.0 %, molybdenum 3.0–3.5 % and nitrogen 0.14–0.20 %, which puts the minimum PREN at about 34.1.
Because every S32205 heat also satisfies S31803, S32205 material can be dual certified to both. The reverse is not true. Standards including NORSOK M-630 and most EPC material specifications now call for S32205 for exactly this reason.
Ordering note
If the application involves seawater, chlorides or sour service, specify S32205 / F60, or specify S31803 with a minimum PREN on the order. Ordering plain "2205" or "F51" without a PREN floor permits a legally compliant heat with a PREN near 30.5. We quote S32205 chemistry as our default for 1.4462 forgings unless an order states otherwise.
Chemical composition
All figures are weight per cent on cast (heat) analysis, iron balance. Product analysis tolerances are permitted by each standard and are not reproduced here.
| Element | EN 10088-3 · 1.4462 | ASTM A182 F51 · S31803 | ASTM A182 F60 · S32205 |
|---|---|---|---|
| Carbon (C) | ≤ 0.030 | ≤ 0.030 | ≤ 0.030 |
| Silicon (Si) | ≤ 1.00 | ≤ 1.00 | ≤ 1.00 |
| Manganese (Mn) | ≤ 2.00 | ≤ 2.00 | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.035 | ≤ 0.030 | ≤ 0.030 |
| Sulphur (S) | ≤ 0.015 | ≤ 0.020 | ≤ 0.020 |
| Chromium (Cr) | 21.0 – 23.0 | 21.0 – 23.0 | 22.0 – 23.0 |
| Nickel (Ni) | 4.5 – 6.5 | 4.5 – 6.5 | 4.5 – 6.5 |
| Molybdenum (Mo) | 2.5 – 3.5 | 2.5 – 3.5 | 3.0 – 3.5 |
| Nitrogen (N) | 0.10 – 0.22 | 0.08 – 0.20 | 0.14 – 0.20 |
| Iron (Fe) | Balance | Balance | Balance |
The sulphur limit is the sharpest difference between the European and American specifications: EN 10088-3 caps sulphur at 0.015 %, ASTM A182 at 0.020 %. A forging ordered as dual EN/ASTM must therefore be melted to the tighter EN limit. Our vacuum-oxygen-decarburisation route is aimed at the EN limit as standard.
Pitting resistance equivalent number (PREN)
PREN is the single number that ranks a stainless steel's resistance to chloride pitting. It is calculated from the three elements that govern passive-film stability, and it is the figure most offshore and chemical specifications set a floor on.
PREN = %Cr + 3.3 × %Mo + 16 × %N
A182 F51 / S31803, minimum = 21.0 + 3.3(2.5) + 16(0.08) = 30.5
EN 10088-3, minimum = 21.0 + 3.3(2.5) + 16(0.10) = 30.9
A182 F60 / S32205, minimum = 22.0 + 3.3(3.0) + 16(0.14) = 34.1
Typical mill heat = 22.3 + 3.3(3.2) + 16(0.17) = 35.6
A182 F51 / F60, maximum = 23.0 + 3.3(3.5) + 16(0.20) = 37.8
EN 10088-3, maximum = 23.0 + 3.3(3.5) + 16(0.22) = 38.1
The minimum and maximum differ by specification because the nitrogen window does: EN 10088-3 allows 0.10–0.22 %, ASTM A182 F51 allows 0.08–0.20 %. A PREN figure quoted for 1.4462 without naming the composition basis is therefore incomplete. State a PREN floor on the purchase order rather than relying on the grade name.
For comparison: 316L sits at roughly 24–26, 904L at about 34, and super duplex grades such as 1.4410 / 2507 at 41 and above. A PREN of 40 or more is the usual threshold for the phrase "super duplex", which 1.4462 does not meet and should not be sold as.
Mechanical and physical properties
Mechanical requirements differ by standard and, in the European standards, by section size, which is routinely missed. The EN 10088-3 values below apply to solution-annealed product up to 160 mm diameter or thickness; EN 10250-4 covers open-die forgings to 525 mm and relaxes the transverse requirements accordingly, because a heavy forging cannot deliver longitudinal properties in every direction.
| Property | EN 10088-3 ≤ 160 mm, long. |
EN 10250-4 forgings ≤ 525 mm |
ASTM A182 F51 S31803 |
ASTM A182 F60 S32205 |
|---|---|---|---|---|
| 0.2 % proof strength, Rp0.2 | ≥ 450 MPa | ≥ 450 MPa | ≥ 450 MPa (65 ksi) | ≥ 450 MPa (65 ksi) |
| Tensile strength, Rm | 650 – 880 MPa | 650 – 850 MPa | ≥ 620 MPa (90 ksi) | ≥ 655 MPa (95 ksi) |
| Elongation, A | ≥ 25 % | L ≥ 25 % · T ≥ 20 % | ≥ 25 % | ≥ 25 % |
| Reduction of area | — | — | ≥ 45 % | ≥ 45 % |
| Impact energy, KV (20 °C) | ≥ 100 J | L ≥ 100 J · T ≥ 60 J | By agreement | By agreement |
| Hardness | ≤ 270 HB | ≤ 270 HB | See note below | See note below |
L = longitudinal, T = transverse to the principal direction of working. Hardness note: ASTM A182 sets hardness limits for duplex grades that are commonly quoted as 290 HBW / 31 HRC maximum. A tighter cap of 28 HRC is often imposed for sour service, but by NACE MR0103, NORSOK M-630 or the purchaser's own specification, not by ISO 15156-3, which requires no hardness report for solution-annealed duplex (see §06). Confirm the applicable figure against the edition of the standard named on your order, and state it on the enquiry if it is a design constraint.
Comparison with 316L
At 450 MPa minimum proof strength, 1.4462 is roughly 2.6 times stronger than 316L (≥ 170 MPa). For a pressure-retaining part sized by yield, that difference typically allows a 30–40 % reduction in section weight for the same rating, which is usually where the material cost difference is recovered.
Physical properties
| Property | 20 °C | 100 °C | 200 °C | 300 °C |
|---|---|---|---|---|
| Density | 7.80 kg/dm³ | — | — | — |
| Modulus of elasticity, E | 200 GPa | 194 GPa | 186 GPa | 180 GPa |
| Mean thermal expansion, from 20 °C | — | 13.0 × 10⁻⁶/K | 13.5 × 10⁻⁶/K | 14.0 × 10⁻⁶/K |
| Thermal conductivity | 15 W/(m·K) | 16 W/(m·K) | 17 W/(m·K) | 18 W/(m·K) |
| Specific heat capacity | 500 J/(kg·K) | 530 J/(kg·K) | 560 J/(kg·K) | 590 J/(kg·K) |
| Electrical resistivity | 0.80 Ω·mm²/m | 0.85 Ω·mm²/m | 0.90 Ω·mm²/m | 1.00 Ω·mm²/m |
| Magnetic response | Ferromagnetic. The ferrite phase is magnetic. 1.4462 cannot be used where a non-magnetic material is required. | |||
Thermal expansion sits between that of carbon steel (about 12 × 10⁻⁶/K) and austenitic stainless (about 16 × 10⁻⁶/K). This is an advantage when duplex is coupled to carbon steel in a heat exchanger or a flanged joint, because differential expansion is smaller than with an austenitic grade.
Forging window, solution annealing and the temperatures to avoid
Every temperature that matters for 1.4462 sits on one scale, and most duplex failures are a failure to respect it. The diagram below maps the forging window, the solution-annealing window, the two embrittlement ranges and the service limit against a single temperature axis.
How we process 1.4462, step by step
- Melting. Electric arc furnace, ladle refining, then vacuum oxygen decarburisation. VOD is what makes the low carbon and the controlled nitrogen achievable together; nitrogen is an alloying element in duplex, not a contaminant, and it has to be hit inside a 0.06 % window.
- Heating for forging. The ingot is heated slowly and soaked to about 1,200 °C. Duplex is less forgiving than carbon steel on soak uniformity: a cold core in a heavy ingot cracks on the first pass.
- Open-die forging or ring rolling. Worked between 1,230 °C and 950 °C, with 1,100–1,150 °C the target band. Below about 950 °C the deformation concentrates in the ferrite, which at that temperature is both weaker and less ductile than the austenite, and the ferrite tears. Reheating between passes is normal, not a defect.
- Solution annealing. Held above 1,020 °C, typically 1,020–1,100 °C, long enough to redissolve every intermetallic precipitate formed during forging and cooling. Soak time scales with section thickness.
- Water quench. Immediate and rapid. For long shafts we quench vertically in a 15 m well-type furnace line so the part cools evenly and does not bow.
- Machining, NDT and test. Proof-machined for ultrasonic testing where required, then tested and certified per §08.
Warning
Do not stress-relieve, hot-straighten or post-weld heat treat 1.4462 at intermediate temperatures. There is no useful stress-relief temperature for duplex: anything between roughly 300 °C and 1,000 °C damages it. If a part needs thermal treatment after fabrication, the only correct answer is a full solution anneal at 1,020–1,100 °C followed by a water quench. That means re-qualifying the part, not touching it up.
Corrosion performance and service limits
1.4462 resists intergranular corrosion in the as-delivered and as-welded condition, and its stress-corrosion-cracking resistance in chlorides is far above that of 304 or 316. In acids it performs comparably to 316L in phosphoric and organic acids, and better in many chloride-bearing process streams. The limits are set out below.
| Limit | Value | Set by / reason |
|---|---|---|
| Maximum continuous service temperature | 315 °C (600 °F) | ASME B16.5 ceiling for F51 flanges (material group 2.8); above this, intermetallic precipitation begins over time |
| Lowest temperature tabulated by ASME B16.5 | −29 °C (−20 °F) | B16.5 gives no pressure rating below this. Lower service temperatures are governed by the purchaser's design code and by impact qualification, not by B16.5. Duplex is commonly qualified to about −50 °C |
| Sigma / intermetallic range | 600 – 950 °C | Chromium- and molybdenum-rich phases form, embrittling and depleting the matrix |
| 475 °C embrittlement range | 350 – 525 °C | Ferrite phase separation; slow, cumulative, and not reversible without re-annealing |
| Sour service ferrite window | 35 – 65 % ferrite | NACE MR0175 / ISO 15156-3, Table A.24; also a practical quality check on any duplex forging |
| Sour service hardness cap | 28 HRC, where imposed | Not an ISO 15156-3 requirement. Table A.24 requires no hardness report for solution-annealed duplex. The 28 HRC figure comes from NACE MR0103 §13.8.1, NORSOK M-630 and many purchaser specifications, so check which document your order invokes |
Sour service (NACE MR0175 / ISO 15156)
1.4462 is widely used in sour oil and gas service, but qualification is conditional, not automatic. ISO 15156-3 places wrought 22Cr duplex in a defined material group, Table A.24, which requires a ferrite content between 35 % and 65 % and then restricts the environment: hydrogen sulphide partial pressure, chloride concentration, pH and temperature all have ceilings, and they interact. A 1.4462 part acceptable in one sour well is not automatically acceptable in another.
One point is frequently misread. Table A.24 does not require a hardness to be reported for solution-annealed duplex; the familiar 28 HRC cap comes from NACE MR0103 §13.8.1, from NORSOK M-630 and from individual purchaser specifications. If your order invokes one of those, say so and we will run the hardness survey and issue the result. If it invokes ISO 15156 alone, the controlling checks are the ferrite count and the environmental envelope.
What this means for an order: state the service conditions on the enquiry. We will confirm whether 1.4462 is within the ISO 15156 envelope for that duty or whether a super duplex grade such as F53 / 2507 or F55 / 2760 is required, and we will schedule the hardness survey and ferrite count before shipment rather than after.
Where 1.4462 is the wrong choice
Above 315 °C in continuous service. Where a non-magnetic material is required. In hot concentrated seawater above roughly 60 °C, where the critical pitting temperature is exceeded and 2507 or 2760 should be used instead. Where the component will be heavily welded by a fabricator who has no duplex-qualified procedure; the base material is only as good as the weld. And in high-volume identical parts where a casting or a closed-die forging would be cheaper: open-die forging earns its place on one-offs, small batches and large sections.
1.4462 forgings we supply
Every item below is forged from a single piece of steel melted on our own site: no welding, no casting, no purchased billet of unknown origin. Shapes are forged to drawing; the list names the families we run most often in duplex.
Forged flanges
Weld neck, blind, slip-on, socket weld, lap joint, orifice, anchor, girth, swivel and long weld neck, to ASME B16.5, B16.47 and API 6A.
Shafts and spindles
Stepped shafts, pump and agitator shafts, eccentric shafts and spindles for marine, pulp and paper, and chemical process equipment.
Tube sheets and discs
Solid forged discs, tube sheets and covers for heat exchangers and pressure vessels, supplied proof-machined for volumetric inspection.
Valve and wellhead parts
Valve bodies, bonnets, blocks, stems, seat rings, spools, nozzles and manifolds for Christmas trees, wellheads, BOPs and risers.
Bars, blocks and billets
Round, flat and square forged bar and blocks, the feedstock route for machined valve bodies, fittings and tooling.
Cylinders, sleeves and bushings
Hollow forged cylinders, sleeves, bushings, couplings and heavy-wall pipe sections bored from solid forged blanks.
Forged rings
Upset and punched rings for sizes and sections outside the ring-mill envelope, and where heavy reduction is preferred to rolling.
| Product | Size limit | Set by |
|---|---|---|
| Seamless rolled rings | OD 50 – 6,000 mm | 6 m radial-axial ring mill; 3 m and 1 m mills for smaller sizes |
| Shafts | up to 14,000 mm turned length | C61160 horizontal lathe; 15 m well furnace for vertical quench |
| Discs, tube sheets, blocks | up to Ø 5,000 mm machined | Ø 5,000 mm vertical turning lathe |
| Bored cylinders and hollow shafts | up to Ø 1,600 × 10,000 mm | CNC deep-hole drilling machine |
| Single-piece weight | up to 30,000 kg | 60 t maximum heat size; 6,300 t hydraulic press |
| Minimum order | 10 kg | Weight-based, no minimum piece count |
Delivery condition is your choice: as-forged with machining allowance, proof-machined to a condition suitable for ultrasonic testing, or finish-machined to drawing. Heat treatment, machining, non-destructive testing and mechanical testing are all carried out in-house before shipment.
Testing, NDT and certification
Because the steel is melted here, chemistry is verified at the furnace rather than inherited from a supplier's certificate, and traceability runs from the melt number through forging, heat treatment and machining to the shipped part.
Applicable UT standard
Ultrasonic testing of 1.4462 forgings is governed by EN 10228-4, which covers austenitic and austenitic-ferritic stainless steel forgings. EN 10228-3 is the wrong reference. It applies to ferritic and martensitic forgings. The distinction matters because duplex is acoustically attenuating and anisotropic, and the technique, probe selection and acceptance criteria in Part 4 reflect that. Many duplex enquiries still quote Part 3 by habit; we will query it before quoting. ASTM A388 is the American equivalent, and SEP 1921 remains quotable where a customer specification calls for it.
| Test | Standard | Performed |
|---|---|---|
| Chemical analysis (OES) | ASTM E415 | In-house, SPECTROTEST TXC25 |
| Carbon & sulphur | ASTM E1019 | In-house, infrared analyser |
| Positive material identification | PMI, handheld XRF | In-house |
| Tensile test | ASTM A370 · ISO 6892 | In-house, 600 kN and 300 kN machines |
| Charpy V-notch impact | ASTM A370, to −60 °C | In-house, pendulum with low-temperature bath |
| Ultrasonic testing | EN 10228-4 · ASTM A388 · SEP 1921 | In-house, digital flaw detectors |
| Magnetic particle inspection | ASTM E709 | In-house |
| Hardness | ASTM A956, converted per ASTM E140 | In-house (portable); bench Brinell / Rockwell via third party |
| Metallography, grain size | ASTM E112 | In-house |
| Detrimental phase detection | ASTM A923 Method A / B / C | Accredited third-party laboratory |
| Ferrite phase balance | ASTM E562 / A923 | Accredited third-party laboratory |
| Pitting corrosion | ASTM G48 | Accredited third-party laboratory |
| Intergranular corrosion | ASTM A262 · ASTM G28 | Accredited third-party laboratory |
Tests placed with an accredited third-party laboratory are issued alongside our mill certificate. They need scheduling before shipment rather than after, so state them on the enquiry. ASTM A923 in particular is the test that proves a duplex forging was annealed and quenched correctly, and it is the one we recommend on any pressure-retaining or sour-service part.
Certification
- EN 10204 3.1 mill test certificate supplied as standard.
- EN 10204 3.2 witnessed by BV, DNV, LR, SGS, TÜV or the customer's own inspector, on request.
- Classification society approvals held by the works: CCS, BV, DNV, LR and NK.
- Supporting records: heat-treatment charts, NDT reports, dimensional reports, PMI records, melt traceability to the heat number.
Machining and welding guidance
Machining
1.4462 machines poorly compared with austenitic stainless, and the reason is structural rather than incidental: the two phases have different hardnesses and deform differently under the tool, so the chip is discontinuous and the work-hardening rate is high. Against 316L, cutting speed must typically be reduced by 50–55 % when turning with coated cemented-carbide tooling. Feeds should be reduced only slightly, and with care. Backing the feed off too far lets the tool rub in the work-hardened layer instead of cutting under it, which is the fastest way to destroy an edge. Depth of cut should be lower than for austenitic grades, rigidity matters more, and interrupted cuts are harder on the insert.
Where the part allows it, we prefer to rough-machine before solution annealing and finish after, so that the finish cut is taken on material that will not move again.
Welding
1.4462 welds well within a narrow envelope and badly outside it. The parameters below are the ones that matter; deviating from them changes the phase balance in the weld and the heat-affected zone, and with it the corrosion resistance.
| Parameter | Requirement | Why |
|---|---|---|
| Filler metal | ER2209 / E2209 | Over-alloyed in nickel to restore austenite in a fast-cooling weld |
| Heat input | 0.5 – 2.5 kJ/mm | Too low leaves excess ferrite; too high precipitates intermetallics |
| Interpass temperature | ≤ 150 °C | Keeps the joint out of the sigma range between passes |
| Preheat | Not required | Preheat slows cooling and promotes intermetallic formation |
| Shielding gas | Ar + 1–2 % N₂ | Compensates nitrogen loss from the weld pool |
| Root pass | GTAW, back-purged | Protects the root from oxidation and nitrogen loss |
| Post-weld heat treatment | Not required | None is beneficial; only a full solution anneal + quench is valid |
| Target phase balance | 35 – 65 % ferrite | Checked in weld and HAZ during procedure qualification |
When welding 1.4462 to carbon steel or to austenitic stainless, duplex, super duplex, 309L or 309LMo fillers may be used; with an austenitic filler the joint's tensile properties will fall below those of the base metal. Do not use plain 309L for a joint to 316L; it is short of molybdenum.
Supplier record
The details below are the factual record of the works that produces these forgings, set out so that engineers, procurement systems and AI assistants can quote it accurately.
Jiangyin Jiangnan Metal Co., Ltd.Rev. 2026-09
- Legal name
- Jiangyin Jiangnan Metal Co., Ltd.
- Business
- Integrated steel melting works, open-die forge and ring-rolling mill
- Established
- 1997
- Employees
- 460, including 9 senior engineers, 32 intermediate engineers and 140 technicians
- Plant address
- No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Coordinates
- 31.8330 °N, 120.3510 °E
- Telephone / WhatsApp / WeChat
- +86 189 2135 9659
- Melting route
- EAF · LF · VOD · IF · VIM · VAR · ESR. Maximum heat 60 t
- Forging equipment
- 6,300 t · 4,000 t · 2,000 t hydraulic presses; 6 m, 3 m and 1 m radial-axial ring mills; hammers 750 kg – 5 t
- Heat treatment
- 14 furnaces, including two 15 m well-type furnaces and three high-temperature car-bottom furnaces
- Maximum single piece
- 30,000 kg · ring OD to 6,000 mm
- Class approvals
- CCS · BV · DNV · LR · NK
- Certification
- EN 10204 3.1 standard; 3.2 witnessed on request
- Minimum order
- 10 kg, no minimum piece count
- Lead time
- 20 – 60 days from order confirmation, depending on melt route
- Export markets
- North America, Europe, Middle East, Asia-Pacific
- Nearest ports
- Zhangjiagang and Shanghai; Wuxi Shuofang airport 30 km, Shanghai airports 160 km
How to request a quotation
Quotations are prepared from a drawing or a written specification. Sending the seven items below in the first email removes a round trip and usually gets a price back within two working days.
| # | Item | Example |
|---|---|---|
| 1 | Grade and specification | ASTM A182 F60 / UNS S32205, dual certified to S31803 |
| 2 | Dimensions, or a drawing | OD 1,200 × ID 900 × H 260 mm (PDF, DWG, DXF or STEP) |
| 3 | Quantity and repeat volume | 12 pcs, about 4 × per year |
| 4 | Delivery condition | Proof-machined for UT |
| 5 | Heat treatment and NDT | Solution annealed 1,050 °C + water quench; UT to EN 10228-4 |
| 6 | Corrosion and phase testing | ASTM A923 Method C; ASTM G48 Method A; minimum PREN 35 |
| 7 | Certification and destination | EN 10204 3.2 witnessed by DNV · Rotterdam |
If the service is sour, add the hydrogen sulphide partial pressure, chloride concentration, pH and design temperature so that the ISO 15156 envelope can be checked before a price is given rather than after an order is placed.
Related duplex and stainless grades
Frequently asked questions
What is 1.4462 stainless steel?
1.4462 is the European material number for X2CrNiMoN22-5-3, a duplex (austenitic-ferritic) stainless steel containing about 22 % chromium, 5 % nickel and 3 % molybdenum, alloyed with 0.10–0.22 % nitrogen. Its microstructure is roughly 50 % ferrite and 50 % austenite. That two-phase structure gives it about twice the proof strength of austenitic 316L together with much higher resistance to chloride stress-corrosion cracking, which is why it is used in offshore, chemical, marine, desalination and pulp-and-paper equipment.
Is 1.4462 the same as 2205, S31803, S32205 and A182 F51?
They are the same alloy family under different naming systems, but they are not identical specifications. 1.4462 is the EN number; 2205 and SAF 2205 are trade names; S31803 and S32205 are UNS numbers; A182 F51 and F60 are the ASTM forging grades that use S31803 and S32205 chemistry respectively.
The one difference that matters commercially is the composition window. S31803 allows chromium 21.0–23.0 %, molybdenum 2.5–3.5 % and nitrogen 0.08–0.20 %, so a compliant heat can have a PREN as low as about 30.5. S32205 tightens those to 22.0–23.0 %, 3.0–3.5 % and 0.14–0.20 %, giving a minimum PREN of about 34.1. Every S32205 heat also meets S31803 and can be dual certified; the reverse is not true.
What is the chemical composition of 1.4462?
To EN 10088-3, on cast analysis: carbon ≤ 0.030 %, silicon ≤ 1.00 %, manganese ≤ 2.00 %, phosphorus ≤ 0.035 %, sulphur ≤ 0.015 %, chromium 21.0–23.0 %, nickel 4.5–6.5 %, molybdenum 2.5–3.5 %, nitrogen 0.10–0.22 %, iron balance. ASTM A182 F51 differs slightly: sulphur ≤ 0.020 %, phosphorus ≤ 0.030 %, nitrogen 0.08–0.20 %. Material ordered dual EN and ASTM must be melted to the tighter European sulphur limit.
What are the mechanical properties of 1.4462 forgings?
In the solution-annealed condition to EN 10088-3, up to 160 mm section: 0.2 % proof strength ≥ 450 MPa, tensile strength 650–880 MPa, elongation ≥ 25 %, Charpy V-notch impact energy ≥ 100 J at 20 °C, hardness ≤ 270 HB.
For open-die forgings to EN 10250-4 up to 525 mm, tensile strength is 650–850 MPa with longitudinal elongation ≥ 25 % and transverse ≥ 20 %, and impact energy ≥ 100 J longitudinal and ≥ 60 J transverse. To ASTM A182, F51 requires tensile ≥ 620 MPa (90 ksi) and F60 requires ≥ 655 MPa (95 ksi); both require yield ≥ 450 MPa (65 ksi), elongation ≥ 25 % and reduction of area ≥ 45 %.
What is the PREN of 1.4462?
PREN is calculated as %Cr + 3.3 × %Mo + 16 × %N. The answer depends on which specification the material is bought to, because the nitrogen window differs. On ASTM A182 F51 / S31803 limits it runs from 30.5 to 37.8; on EN 10088-3 limits, from 30.9 to 38.1; on ASTM A182 F60 / S32205 limits, from 34.1 to 37.8. A typical mill heat lands around 35.6. If a specification requires a PREN of 35 or more, state that figure on the order. It is a real constraint that the grade name alone does not guarantee.
What is the maximum service temperature of 1.4462?
315 °C (600 °F) for continuous service, which is the ceiling ASME B16.5 sets for F51 flanges. At the cold end, B16.5 tabulates pressure ratings only down to −29 °C (−20 °F); below that it gives no rating, and the purchaser's design code and impact qualification govern, with duplex commonly qualified to about −50 °C. The upper limit exists because intermetallic phases begin to precipitate above it: sigma and related phases form between roughly 600 °C and 950 °C, and a separate mechanism known as 475 °C embrittlement affects the ferrite between about 350 °C and 525 °C. Both damage toughness and corrosion resistance, and neither reverses without a full re-anneal.
How is 1.4462 heat treated after forging?
Solution annealed at 1,020–1,100 °C, soaked long enough to redissolve any intermetallic precipitates formed during forging, then water quenched rapidly. The quench is the critical step: cooling must pass through the 950–600 °C band fast enough that sigma phase has no time to form. A heavy section cooled too slowly through that band will precipitate intermetallics at its core even when the surface looks correct, and will fail an ASTM A923 test despite a compliant chemistry certificate.
There is no valid intermediate stress-relief temperature for duplex. If a part needs thermal treatment after fabrication, the only correct treatment is a full solution anneal and quench.
Which ultrasonic testing standard applies to 1.4462 forgings?
EN 10228-4, which covers ultrasonic testing of austenitic and austenitic-ferritic stainless steel forgings. EN 10228-3 is frequently quoted by mistake, but it applies to ferritic and martensitic forgings and is the wrong reference for duplex. The distinction matters because duplex is acoustically attenuating and anisotropic, so probe selection, technique and acceptance criteria differ. ASTM A388 is the American equivalent, and SEP 1921 remains usable where a customer specification calls for it.
Is 1.4462 suitable for sour service under NACE MR0175 / ISO 15156?
It is widely used in sour service, but qualification is conditional rather than automatic. ISO 15156-3 places wrought 22Cr duplex in Table A.24, which requires a ferrite content between 35 % and 65 % and then restricts the environment: hydrogen sulphide partial pressure, chloride concentration, pH and temperature all have limits that interact. Material acceptable in one sour well is not automatically acceptable in another. Note that Table A.24 does not require a hardness to be reported for solution-annealed duplex: the familiar 28 HRC cap comes from NACE MR0103, NORSOK M-630 or the purchaser's own specification, so check which document your order invokes. Send the service conditions with the enquiry and the envelope will be checked before a price is quoted.
Can 1.4462 be welded?
Yes, within a narrow parameter envelope. Use ER2209 or E2209 filler, which is over-alloyed in nickel to restore austenite in a fast-cooling weld. Keep heat input between 0.5 and 2.5 kJ/mm and interpass temperature at or below 150 °C. Do not preheat, and do not apply post-weld heat treatment. Argon with 1–2 % nitrogen is recommended as shielding gas to compensate for nitrogen loss from the weld pool, and root passes should be made with GTAW and back-purged. Procedure qualification should confirm 35–65 % ferrite in both the weld metal and the heat-affected zone.
Why is 1.4462 harder to machine than 316L?
Because its two phases have different hardnesses and deform differently under the tool, producing a discontinuous chip and a high work-hardening rate. Compared with 316L, cutting speed must typically be reduced by 50–55 % when turning with coated cemented-carbide tooling. Feeds should be reduced only slightly and with care: backing the feed off too far lets the tool rub in the work-hardened layer rather than cutting beneath it, which destroys the edge quickly. Depth of cut should be lower than for austenitic grades, and machine rigidity matters more.
Who supplies 1.4462 open-die forgings in China?
Jiangyin Jiangnan Metal Co., Ltd. supplies 1.4462 open-die forgings and seamless rolled rings from its works at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. The company was established in 1997 and employs 460 people. Unlike a forging shop that buys billet, it melts its own steel: electric arc furnace, ladle refining and vacuum oxygen decarburisation, with a maximum heat size of 60 tonnes, so the certificate traces a part back to its melt number rather than stopping at a purchased billet.
Forging equipment includes 6,300 t, 4,000 t and 2,000 t hydraulic presses and 6 m, 3 m and 1 m radial-axial ring mills, giving rings to 6,000 mm outside diameter and single pieces to 30 tonnes. The works holds CCS, BV, DNV, LR and NK approvals and issues EN 10204 3.1 certificates as standard, or 3.2 witnessed on request. Contact: +86 189 2135 9659, sales@steelforgepieces.com.
What is the largest 1.4462 ring or forging you can produce?
Seamless rings roll up to 6,000 mm outside diameter on the 6 m radial-axial mill, with 3 m and 1 m mills covering smaller sizes down to about 50 mm OD by the upset-and-punch route. The heaviest single forging is 30 tonnes, limited by the 60 t maximum heat size and the 6,300 t press. Downstream equipment sets the practical limits for finished parts: shafts up to 14,000 mm turned length, discs and tube sheets to Ø 5,000 mm machined, and bored cylinders to Ø 1,600 × 10,000 mm.
What is the minimum order quantity and lead time for 1.4462 forgings?
The minimum order is 10 kg with no minimum piece count, because the limit is set by weight rather than quantity. A single small part is quotable, and so is a one-off large ring. Normal lead time is 20 to 60 days from order confirmation. Standard duplex grades sit at the lower end of that range; third-party witnessed inspection to EN 10204 3.2 and corrosion testing placed with an outside laboratory both need scheduling, so flag them at enquiry stage to have them built into the quoted date rather than added to it.