Jiangyin Jiangnan Metal Co., Ltd. Melting works and open-die forging factory, Jiangyin, Jiangsu, China +86 189 2135 9659 sales@steelforgepieces.com
SteelForgePieces

Material No. 1.4460 · X3CrNiMoN27-5-2 · Duplex

1.4460 Forged Steel Components

Open-die forged bars, seamless rolled rings, flanges, valve parts and custom forgings in X3CrNiMoN27-5-2 duplex stainless steel. Melted, forged, solution annealed and tested at our own works in Jiangyin, Jiangsu, and shipped worldwide with EN 10204 3.1 certificates.

EN designation
X3CrNiMoN27-5-2
Structure
Austenitic-ferritic (duplex)
Standards
EN 10088-3 · EN 10250-4
EN 10088-1 · ISO 15510
Chromium
25.0 to 28.0 %
PREN
30.1 to 37.8
Delivery condition
+AT solution annealed

Quick answer

1.4460 (EN designation X3CrNiMoN27-5-2) is an austenitic-ferritic duplex stainless steel containing 25.0 to 28.0 % chromium, 4.5 to 6.5 % nickel, 1.30 to 2.00 % molybdenum and 0.05 to 0.20 % nitrogen, with carbon held to 0.05 % maximum. It is supplied solution annealed, and in that condition minimum 0.2 % proof strength is 450 MPa with tensile strength of 620 to 880 MPa for product up to 160 mm.

1.4460 has no exact American equivalent. It is widely cross-referenced to AISI 329 / UNS S32900, but S32900 specifies no nitrogen at all and allows nickel down to 2.0 %, so a 329 certificate can sit legitimately outside the 1.4460 band. By chemistry the closest UNS grade is S31200, which is also what the ISO 15510 designation 4460-312-00-I points to.

Duplex grades are ferrite-bearing, so 1.4460 is magnetic and its service temperature is capped at roughly 250 °C by 475 °C embrittlement of the ferrite phase, not by strength. Hot forming runs 950 to 1200 °C and solution annealing 1020 to 1100 °C with rapid cooling.

Jiangyin Jiangnan Metal Co., Ltd. forges 1.4460 into round and hollow bars, seamless rolled rings to 6,000 mm outside diameter, flanges, discs, tube sheets, valve bodies, pump shafts and custom parts at its integrated melting and open-die forging works at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. Steel for duplex orders is melted on site through the electric arc furnace, ladle furnace and vacuum oxygen decarburisation route, so nitrogen is set at the furnace rather than accepted from a purchased billet. Quotations are returned within two working days. Call +86 189 2135 9659 or email sales@steelforgepieces.com.

What is 1.4460 steel?

1.4460 is the EN material number for X3CrNiMoN27-5-2, a duplex stainless steel whose structure is roughly half ferrite and half austenite after correct solution annealing. It belongs to the older, high-chromium end of the duplex family, with 27 % nominal chromium but only about 1.5 % molybdenum.

The two-phase structure is where the properties come from. Ferrite carries the strength and the resistance to chloride stress corrosion cracking; austenite carries the toughness and ductility. The result is a steel with roughly double the proof strength of 304 or 316 at a similar price band for chromium-rich chemistry, and with far better resistance to chloride stress corrosion cracking than any standard austenitic grade.

What separates 1.4460 from the modern duplex grades is the balance of the alloying elements. Nitrogen was a later addition to duplex metallurgy, and 1.4460 carries it with a minimum of only 0.05 %, against 0.10 % for 1.4462 and 0.24 % for super duplex grades. Molybdenum is also low. Chromium is high enough to keep the pitting resistance competitive on paper, but the grade behaves differently in welding and heat treatment than the nitrogen-rich grades that replaced it.

In current practice 1.4460 is specified where a drawing, a European plant standard or an existing spare calls for it by number, and in phosphoric acid, fertiliser and organic acid service where its chromium content does real work. For a new chloride-service design, most engineers now reach for 1.4462 instead, for the reasons set out under corrosion resistance.

Chemical composition of 1.4460

Chemical composition of 1.4460 / X3CrNiMoN27-5-2 per EN 10088-3:2014, in weight percent. Balance iron.
CSiMnP SCrNiMo N
max 0.05max 1.00max 2.00max 0.035 max 0.03025.0–28.04.5–6.51.30–2.00 0.05–0.20
Controlled sulphur is permitted and worth asking for. EN 10088-3 allows sulphur to be held in narrower bands for particular purposes: 0.015 to 0.030 % for machinability, 0.008 to 0.030 % for weldability, and 0.015 % maximum for polishability. EN 10088-1 lists the grade at 0.015 % maximum. If parts are going to be welded into an assembly, state the weldability band on the order rather than accepting the general 0.030 % ceiling.
The nitrogen range is the one to watch. A heat at 0.05 % nitrogen and a heat at 0.20 % nitrogen both pass EN 10088-3, but they do not behave the same. Nitrogen stabilises austenite and speeds its re-formation in the heat-affected zone after welding. At the bottom of the range the weld HAZ can finish ferrite-rich, which costs toughness and pitting resistance in exactly the place a joint is most exposed. Because we melt our own steel, a nitrogen minimum above the standard floor can be written into the order and set at the furnace.

Which UNS number does 1.4460 actually match?

Almost every published cross-reference table gives 1.4460 as AISI 329 / UNS S32900. That answer is good enough for a stockist and not good enough for a purchase order. The three American grades usually offered against 1.4460 have materially different chemistry, and only one of them specifies nitrogen in a way that matches.

Composition of 1.4460 compared with the American grades commonly offered against it. ASTM figures from ASTM A240 / A182. Values in weight percent.
Element 1.4460
EN 10088-3
S32900
Type 329
S31200
A182 F50
S32950
A182 F52
Carbon, max0.050.080.0300.030
Chromium25.0–28.023.0–28.024.0–26.026.0–29.0
Nickel4.5–6.52.0–5.05.5–6.53.5–5.2
Molybdenum1.30–2.001.00–2.001.20–2.001.00–2.50
Nitrogen0.05–0.20not specified0.14–0.200.15–0.35
Min. Rp0.2450 MPa485 MPa450 MPa485 MPa
Rm620–880 MPa620 MPa min690 MPa min690 MPa min

Read the nitrogen row first. S32900 specifies no nitrogen requirement at all, and allows nickel as low as 2.0 %, well under the 4.5 % floor of 1.4460. A mill can produce steel that is fully compliant Type 329 and simultaneously out of specification against X3CrNiMoN27-5-2 on two elements. When a drawing says 1.4460 and the certificate says 329, that gap is where incoming-inspection disputes come from.

S31200 is the closer match. Its nitrogen band of 0.14 to 0.20 % sits inside the 1.4460 range, its nickel band of 5.5 to 6.5 % sits inside it too, and molybdenum is almost identical. ISO 15510 agrees: it assigns 1.4460 the designation 4460-312-00-I, and the 312 in that number is Type 312, the older name for S31200. S32950 (A182 F52) is a third partial match, with higher chromium and a nitrogen floor above the EN minimum.

What to write on the order. If the part is going into a European system, specify EN 10250-4 X3CrNiMoN27-5-2 for forgings, not just the number 1.4460, because EN 10250-4 is the forging standard and EN 10088-3 covers bars and bright products. If the part is going into an American system, specify ASTM A182 F50 (S31200) rather than 329 when the drawing origin is 1.4460. If both apply, ask for dual certification and state the tighter limits of each standard as the governing chemistry.

Mechanical properties of 1.4460

Solution annealed bar, rod, section and forged product

Room-temperature mechanical properties of 1.4460 in the solution annealed (+AT) condition per EN 10088-3:2014, for product up to 160 mm.
PropertyRequirementImperial
0.2 % proof strength Rp0.2min 450 MPa65 ksi
Tensile strength Rm620–880 MPa90–128 ksi
Elongation A, longitudinalmin 20 %min 20 %
Charpy KV, longitudinalmin 85 J63 ft-lb
Brinell hardnessmax 260 HBWmax 260 HBW
Intergranular corrosion resistanceResistant as delivered and after welding

Cold drawn and ground bar

Mechanical properties of cold drawn (2H, 2B) and ground (2G) 1.4460 bar in the solution annealed condition, per EN 10088-3:2014. Elongation values apply to sizes of 5 mm and above.
DiameterRp0.2 min RmA minKV min
up to 10 mm610 MPa770–1030 MPa12 %–
over 10 to 16 mm560 MPa770–1030 MPa12 %–
over 16 to 40 mm460 MPa620–950 MPa15 %85 J
over 40 to 63 mm460 MPa620–950 MPa15 %85 J
over 63 to 160 mm460 MPa620–880 MPa20 %85 J
Tensile strength has a ceiling, not just a floor. The 880 MPa upper limit is a requirement, and on duplex it is a quality check rather than a formality. A result above the band on a solution annealed forging usually means the cool from annealing was too slow and intermetallic phase has formed, or that residual cold work was never removed. Either explanation points at the same corrective action: re-anneal and quench properly.

Elevated-temperature properties and the 250 °C ceiling

Minimum 0.2 % proof strength of solution annealed 1.4460 at elevated temperature, in MPa.
Temperature100 °C150 °C200 °C250 °C
Rp0.2, +AT360335310295

That table stops at 250 °C for a metallurgical reason, not for lack of data. Above roughly 250 to 300 °C the ferrite phase in any duplex stainless steel begins to separate into chromium-rich and iron-rich regions, a process usually called 475 °C embrittlement because it runs fastest near that temperature. It is slow at 300 °C and rapid at 475 °C, and it is cumulative over the life of the part. The steel loses impact toughness and gains hardness while its room-temperature tensile figures look unchanged, so routine testing does not find it.

The practical consequence is that 1.4460 is a strength-and-corrosion material for ambient and warm service, not a high-temperature material, despite its chromium content. European pressure equipment practice caps duplex grades around 250 °C for this reason. If a design needs both corrosion resistance and sustained service above that, the answer is an austenitic grade such as 904L or a nickel alloy such as Incoloy 825, not a duplex.

The same phase chemistry sets a low-temperature limit. Duplex grades lose toughness below about −50 °C as the ferrite passes through its ductile-to-brittle transition. For cryogenic work an austenitic grade is the correct choice.

Physical properties of 1.4460

Indicative physical properties of 1.4460 in the solution annealed condition at room temperature. Confirm against the applicable design code for calculation purposes.
PropertyMetricImperial
Density7.8 g/cm³0.282 lb/in³
Modulus of elasticity200 GPa29 × 10⁶ psi
Shear modulus80 GPa11.6 × 10⁶ psi
Poisson's ratio0.270.27
Thermal conductivity15 W/(m·K)8.7 BTU/(h·ft·°F)
Specific heat capacity480 J/(kg·K)0.11 BTU/(lb·°F)
Mean thermal expansion13 × 10⁻⁶/K7.2 × 10⁻⁶/°F
Electrical resistivity0.80 µΩ·m2.2 % IACS
Melting range1390–1430 °C2530–2610 °F
Magnetic responseFerromagnetic, from the ferrite phase
Two of these numbers govern how the steel is processed. Thermal conductivity of 15 W/(m·K) is under half that of carbon steel, so heat does not leave the cut zone during machining and does not leave the core during quenching. Thermal expansion of 13 × 10⁻⁶/K is about two thirds that of an austenitic grade, which is why duplex distorts less than 316 when welded and is easier to hold to tolerance across a large ring.
It is magnetic, and that is normal. Around half the structure is ferrite, so 1.4460 responds to a magnet. This regularly causes an incoming-inspection query from people used to austenitic stainless. A magnet is not a valid grade check on duplex. Use positive material identification, which we run on every heat, or a full chemical analysis.

Corrosion resistance and PREN

Pitting resistance for stainless steels is estimated from the pitting resistance equivalent number, PREN = %Cr + 3.3 × %Mo + 16 × %N. Applied to the EN limits for 1.4460 it gives a range rather than a figure.

PREN calculated from the composition limits of 1.4460 and compared with 1.4462 and 1.4410. A PREN of 34 and above is generally taken as the threshold for seawater service.
GradeCrMoNPREN range
1.446025.0–28.01.30–2.000.05–0.2030.1–37.8
1.4462 (2205)21.0–23.02.50–3.500.10–0.2230.9–38.1
1.4410 (2507)24.0–26.03.00–5.000.24–0.3537.7–48.1

The spread inside 1.4460 is the point. A heat at the top of the chromium, molybdenum and nitrogen ranges reaches PREN 37.8 and is a credible seawater material. A heat at the bottom of all three reaches 30.1 and is not. Both are fully compliant 1.4460. If the application is chloride service, a PREN minimum belongs on the purchase order, and it should be supported by an ASTM G48 pitting test at a stated temperature rather than by the calculation alone.

Where 1.4460 performs well is general corrosion in acidic media, thanks to the high chromium, and resistance to chloride stress corrosion cracking, where any duplex grade is far ahead of 304 and 316. Phosphoric acid, fertiliser production, organic acids and brackish or seawater cooling circuits are the classic duties. The grade also retains its resistance to intergranular corrosion both as delivered and after welding, which is a stated requirement of EN 10088-3 rather than a claim.

1.4460 against 1.4462, in one line. Their PREN ranges overlap almost exactly, but 1.4460 buys its pitting resistance with chromium while 1.4462 buys it with molybdenum and nitrogen. For equal PREN, the nitrogen-rich grade welds more forgivingly and holds its phase balance better, which is why 1.4462 has taken over most new chloride-service design. 1.4460 keeps its place where the chemistry suits the medium, in acid service, and where an existing specification calls for it.

Forging and heat treatment of 1.4460

Duplex stainless is less forgiving to forge than austenitic stainless, and heavy sections are where it gets difficult. Both problems come from the same source: the steel must spend as little time as possible between about 600 and 1000 °C, where sigma and chi phases precipitate and take the toughness and corrosion resistance with them.

Forging and solution annealing cycle for 1.4460 Temperature against time. The billet is soaked at 1150 to 1200 degrees Celsius, forged down to a finish temperature of 950, cooled, then solution annealed at 1020 to 1100 degrees Celsius and quenched rapidly through the sigma phase band between 1000 and 600 degrees Celsius. 1200 °C 1000 °C 600 °C 20 °C 1150–1200 soak forge, finish at 950 1020–1100 solution anneal water quench fast through this band sigma phase range Time
Processing route for 1.4460 open-die forgings. The shaded band between 600 and 1000 °C is where sigma and chi phases form, and the quench has to cross it quickly at the core of the part, not just at the surface.
Forging and heat treatment parameters for 1.4460 / X3CrNiMoN27-5-2.
OperationTemperatureCooling
Soaking before forging1150 – 1200 °C
(2100 – 2190 °F)
–
Hot forming range1200 down to 950 °C
(2190 to 1740 °F)
Air, then anneal
Solution annealing (+AT)1020 – 1100 °C
(1870 – 2010 °F)
Water or forced air, rapid
Stress reliefNot applicable. Use a full solution anneal and quench
Hardening by heat treatmentNot possible. Strength comes from the duplex structure and cold work

Why the finish temperature matters

The hot working window closes at about 950 °C. Below that, the ferrite work-hardens faster than the austenite and the two phases stop deforming together, which opens edge cracks and surface tearing. The practical effect on a large ring or a long shaft is that the forging has to be returned to the furnace and reheated rather than worked down cold, and each reheat is time and cost. Quoting duplex realistically means allowing for those reheats rather than pricing it like a carbon steel forging of the same weight.

Why the quench is the real risk on heavy sections

Solution annealing puts the alloying elements back into solution and restores the phase balance. The quench that follows has to carry the part through the 1000 to 600 °C band fast enough that sigma phase has no time to form. On a 40 mm bar that is straightforward. On a 300 mm section, a large disc or a thick-walled ring, the core cools far more slowly than the surface, and sigma can form at the centre of a part whose surface tests perfectly.

Three things decide the outcome, and all three are shop-floor practice rather than specification: the transfer time from furnace to quench tank, the volume and agitation of the water, and whether the part is loaded so the water reaches all surfaces. Our 14 heat-treatment furnaces sit alongside the quench, which keeps the transfer short. For heavy duplex sections we quote proof machining before the final anneal where the geometry allows it, because removing stock before the quench reduces the section the water has to cool.

The test that proves it. Sigma phase is invisible to a tensile test and to a hardness check at the surface. ASTM A923 exists for this: Method A is a metallographic screen, Method B is a Charpy impact test, and Method C is a ferric chloride corrosion test. For critical duplex forgings, specify A923 on a test piece taken from the mid-thickness of the heaviest section, not from a separately forged coupon. We place A923 and ASTM G48 with an accredited third-party laboratory and issue the report alongside the mill certificate.

Welding 1.4460

1.4460 can be welded with all the common arc processes. Gas welding is not suitable. Unlike martensitic grades, it needs neither preheat nor post-weld heat treatment, and for most fabrication a correctly run joint is used as welded.

  • No preheat required
  • Heat input kept low and controlled
  • Interpass temperature typically 150 °C maximum
  • Over-alloyed filler, 25 Cr type or nickel-based
  • Nitrogen-bearing shielding gas where available
  • Surfaces clean, dry and free of grease before striking

The reason to keep heat input low and to use an over-alloyed filler is the same reason the nitrogen range matters. On cooling from welding temperature the heat-affected zone re-forms austenite from a fully ferritic structure, and it needs time and nitrogen to do so. Too fast a cool or too little nitrogen leaves the HAZ ferrite-rich, with lower toughness and lower pitting resistance than the parent metal. A filler carrying two to three percent more nickel than the parent compensates on the weld metal side; controlled heat input handles the HAZ side.

Where a welded assembly is going into severe service, the check is a ferrite count on the HAZ, by point count to ASTM E562 or by calibrated Ferritescope, with a target band typically 35 to 65 % ferrite. If a weld procedure has to be qualified, qualify it on material from the same heat as the production parts, since the nitrogen level inside the EN range changes the HAZ response.

Machining 1.4460

Duplex machines harder than its hardness number suggests. At a maximum of 260 HBW the material looks moderate, but the ferrite and austenite phases cut differently, the steel work-hardens rapidly, and thermal conductivity of 15 W/(m·K) means the heat generated at the tip stays at the tip.

The practical rules are rigid clamping, positive rake coated carbide or high-grade high-speed steel, generous flood coolant, and a deliberate policy of never dwelling. A tool that rubs instead of cutting work-hardens the surface and the next pass has to cut through that layer. Depth of cut should stay below the work-hardened skin left by the previous pass, which in practice means fewer, deeper passes rather than many light ones.

We supply 1.4460 forgings as forged with machining allowance, proof machined to a finish suitable for ultrasonic examination, or finish machined to drawing on vertical lathes up to 5,000 mm swing and horizontal lathes up to 14,000 mm between centres. If parts will be machined in your own shop and the grade is new to it, ask for the material in the proof-machined condition so that the first cut starts below the as-forged skin.

1.4460 equivalent grades and cross-reference

The designations below refer to the same nominal grade across standards bodies. As set out under the UNS question, the American entries are approximate rather than identical, and the chemistry should be checked against the governing standard before a substitution is accepted.

International designations for 1.4460 / X3CrNiMoN27-5-2 duplex stainless steel.
Standard or systemDesignationNote
EN material number1.4460All product forms
EN chemical designationX3CrNiMoN27-5-2All product forms
EN 10250-4X3CrNiMoN27-5-2Open die forgings and rolled rings
EN 10088-3X3CrNiMoN27-5-2Bars, rods, sections, bright products
ISO 155104460-312-00-IThe 312 refers to Type 312 / S31200
UNS, closest by chemistryS31200ASTM A182 F50, nitrogen specified
UNS, common referenceS32900Approximate, no nitrogen requirement
AISI / SAE329Approximate
ASTM A182F50 / F52Forgings, flanges, valve parts
JIS (Japan)SUS329J1Approximate
AFNOR (France)Z5CND27-05AzApproximate
SS (Sweden)2324Approximate
UNE (Spain)F.3552Approximate
GOST (Russia)10Ch26N5MApproximate
GB (China)022Cr25Ni6Mo2NApproximate

Forged shapes we supply in 1.4460

Round bars and rods

Solid round, square, flat and hexagonal forged bar

Hollow bars and sleeves

Bushings, shells, cylinders, forged tube blanks

Seamless rolled rings

Radial-axial rolled rings to 6,000 mm outside diameter

Flanges and discs

Forged flanges, blanks, discs, plates and blocks

Tube sheets and covers

Heat-exchanger tube sheets, proof machined for testing

Valve components

Bodies, bonnets, seats, seat rings, stems, wedges

Shafts and stirrers

Pump shafts, stirrer shafts, spindles, pistons, bolts

Custom forgings

Any profile forged to your 2D drawing or 3D model

Our 1.4460 forging capability

Jiangyin Jiangnan Metal Co., Ltd. has been an integrated melting and open-die forging works in Zhouzhuang Town, Jiangyin, Jiangsu since 1997. Most forging suppliers in China buy billet. This plant starts one step earlier, at the furnace, which matters more for duplex than for most grades: nitrogen is set during vacuum oxygen decarburisation rather than inherited from a purchased bar, and the certificate traces the part back to its melt number.

Melting
Electric arc furnace, ladle furnace and vacuum oxygen decarburisation for duplex and stainless grades. Maximum heat size 60 tonnes
Forging
6,300 t, 4,000 t and 2,000 t hydraulic open-die presses, five hammers from 750 kg to 5 t
Ring rolling
Radial-axial mills at 6 m, 3 m and 1 m, maximum ring outside diameter 6,000 mm
Size limits
Single-piece weight to 30 t, turned shaft length to 14,000 mm, machined diameter to 5,000 mm, bored bores to 1,600 mm diameter by 10,000 mm
Heat treatment
14 furnaces on site including two 15 m well-type furnaces for vertical quenching of long shafts, with recorded furnace charts
Machining
As forged with allowance, proof machined for ultrasonic testing, or finish machined to drawing
In-house testing
Optical emission spectrometry, carbon and sulphur analysis, positive material identification, tensile to 600 kN, Charpy impact to −60 °C, ultrasonic and magnetic particle examination, metallography
Third-party testing
ASTM A923 phase balance, ASTM G48 pitting, ASTM A262 and G28 intergranular corrosion, placed with an accredited laboratory and reported with the mill certificate
Approvals
CCS, BV, DNV, LR and NK classification society approvals
Certification
EN 10204 3.1 as standard, 3.2 witnessed by a classification society, SGS, TÜV or your own inspector on request
Minimum order
10 kg, with no minimum piece count
Lead time
20 to 60 days from order confirmation
Quotation
Returned within two working days
Works address
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Contact
+86 189 2135 9659 · sales@steelforgepieces.com

Applications of 1.4460 forgings

  • Pump casings, shafts and impeller hubs
  • Valve bodies, bonnets and seat rings
  • Heat-exchanger tube sheets and covers
  • Pressure-vessel flanges and nozzles
  • Phosphoric acid and fertiliser plant parts
  • Stirrer and agitator shafts
  • Seawater and brackish water cooling circuits
  • Marine and offshore fittings and couplings
  • Chlorine-bearing housings and pipework parts
  • Pulp and paper digester components
  • Special anchors, tie rods and fasteners
  • Screw conveyors and wear-exposed machine parts

How to order 1.4460 forgings

  1. Send the drawing or dimensions Email a 2D drawing, 3D model or rough dimensions to sales@steelforgepieces.com. Without a drawing, send outside diameter, inside diameter, length or thickness, and quantity. Minimum order is 10 kg with no minimum piece count.
  2. State the standard and any restricted chemistry Confirm EN 10250-4 X3CrNiMoN27-5-2 for forgings, EN 10088-3 for bar, or an American grade such as ASTM A182 F50. For chloride service, state any nitrogen minimum or PREN minimum you want held above the standard floor.
  3. Confirm the delivery condition Solution annealed at 1020 to 1100 °C with rapid cooling, supplied as forged with allowance, proof machined for ultrasonic testing, or finish machined to drawing.
  4. Confirm testing and certification Specify EN 10204 3.1 or 3.2, plus any duplex-specific testing: ASTM A923 phase balance, ferrite count, ASTM G48 pitting, ASTM A262 or G28 intergranular corrosion, and ultrasonic examination.
  5. Receive the quotation Unit price, forging weight, lead time and Incoterms come back within two working days. Normal lead time runs 20 to 60 days from order confirmation.

Frequently asked questions about 1.4460

What is 1.4460 stainless steel?

1.4460 is the EN material number for X3CrNiMoN27-5-2, an austenitic-ferritic duplex stainless steel containing 25.0 to 28.0 % chromium, 4.5 to 6.5 % nickel, 1.30 to 2.00 % molybdenum and 0.05 to 0.20 % nitrogen, with carbon at 0.05 % maximum. Its structure is roughly half ferrite and half austenite, which gives it about double the proof strength of 304 or 316 along with strong resistance to chloride stress corrosion cracking. It is standardised in EN 10088-3 for bars and bright products and in EN 10250-4 for open die forgings.

What is the American equivalent of 1.4460?

There is no exact equivalent. The commonly published cross-reference is AISI 329 / UNS S32900, but S32900 specifies no nitrogen requirement and allows nickel down to 2.0 %, against the 4.5 % minimum of 1.4460, so compliant 329 material can fall outside the EN band. By chemistry the closest UNS grade is S31200 (ASTM A182 F50), with nitrogen at 0.14 to 0.20 % and nickel at 5.5 to 6.5 %, both inside the 1.4460 ranges. ISO 15510 agrees, assigning 1.4460 the designation 4460-312-00-I, where 312 refers to Type 312 / S31200. S32950 (A182 F52) is a third partial match.

What is the tensile strength and yield strength of 1.4460?

In the solution annealed condition for product up to 160 mm, EN 10088-3 requires a minimum 0.2 % proof strength of 450 MPa (65 ksi) and a tensile strength of 620 to 880 MPa (90 to 128 ksi), with minimum longitudinal elongation of 20 %, minimum longitudinal Charpy KV of 85 J and hardness not exceeding 260 HBW. Cold drawn bar is stronger: up to 10 mm diameter the minimum proof strength is 610 MPa with tensile strength of 770 to 1030 MPa.

Is 1.4460 magnetic?

Yes. Roughly half the structure is ferrite, which is ferromagnetic, so 1.4460 responds strongly to a magnet. This is normal for every duplex stainless steel and is not a sign of contamination or of the wrong grade. It does mean a magnet is not a valid way to verify the material at incoming inspection. Use positive material identification or a full chemical analysis instead.

What is the maximum service temperature of 1.4460?

About 250 °C for continuous service. The limit is not strength but 475 °C embrittlement: above roughly 250 to 300 °C the ferrite phase separates into chromium-rich and iron-rich regions, and the steel loses impact toughness cumulatively over time while its room-temperature tensile figures look unchanged. Published proof-strength data for the grade stops at 250 °C for this reason. Duplex grades also lose toughness below about −50 °C, so they are not cryogenic materials either.

What is the PREN of 1.4460?

Between 30.1 and 37.8, depending where the heat sits inside the composition limits. PREN is calculated as %Cr + 3.3 × %Mo + 16 × %N, so a heat at the minimum of chromium, molybdenum and nitrogen gives 30.1 while one at the maximum gives 37.8. Both are fully compliant 1.4460. Since 34 is the usual threshold for seawater service, a PREN minimum belongs on the purchase order for chloride applications, supported by an ASTM G48 pitting test rather than by the calculation alone.

What heat treatment is applied to 1.4460 forgings?

Solution annealing at 1020 to 1100 °C followed by rapid cooling in water or forced air. Hot forming runs from 1200 °C down to a finish temperature of about 950 °C. The grade cannot be hardened by heat treatment; its strength comes from the duplex structure and from cold work. Stress relief at intermediate temperature is not used, because holding in the 600 to 1000 °C range precipitates sigma phase. Where stress relief is needed, a full solution anneal and quench is the correct treatment.

Why does the quench matter so much on heavy 1.4460 sections?

Because sigma and chi phases form between about 600 and 1000 °C, and the quench has to carry the part through that band quickly at the core, not just at the surface. On a 40 mm bar this is straightforward. On a 300 mm section, a thick ring or a large disc, the centre cools far more slowly and sigma can form there while the surface tests perfectly. Transfer time from furnace to quench tank, water volume and agitation, and how the part is loaded all decide the outcome. Sigma phase is invisible to a tensile test and to a surface hardness check, which is why ASTM A923 exists.

Can 1.4460 be welded?

Yes, with all common arc processes. Gas welding is not suitable. No preheat and no post-weld heat treatment are required. Keep heat input low, hold interpass temperature to about 150 °C maximum, and use an over-alloyed filler of the 25 Cr type or a nickel-based consumable. The reason is that the heat-affected zone re-forms austenite from a fully ferritic structure on cooling, and needs time and nitrogen to do so. Too fast a cool leaves the HAZ ferrite-rich, with lower toughness and pitting resistance than the parent metal. For severe service, check the HAZ ferrite count to ASTM E562 or with a calibrated Ferritescope, typically targeting 35 to 65 % ferrite.

What is the difference between 1.4460 and 1.4462 (2205)?

1.4460 has higher chromium at 25.0 to 28.0 % against 21.0 to 23.0 %, but lower molybdenum at 1.30 to 2.00 % against 2.50 to 3.50 %, and lower nitrogen at a 0.05 % minimum against 0.10 %. Their PREN ranges overlap almost exactly, so on paper the pitting resistance is comparable, but 1.4460 buys it with chromium while 1.4462 buys it with molybdenum and nitrogen. The nitrogen-rich grade welds more forgivingly and holds its phase balance better, which is why 1.4462 has taken over most new chloride-service design. 1.4460 keeps its place in acid service and wherever an existing specification calls for it by number.

Is 1.4460 suitable for seawater?

It depends on the heat, which is an unusual answer but the correct one. Seawater service generally requires PREN of 34 or above, and 1.4460 spans 30.1 to 37.8 across its composition limits. A heat near the top of the chromium, molybdenum and nitrogen ranges qualifies; a heat near the bottom does not. If the duty is seawater or another chloride-bearing medium, state a PREN minimum on the order and require an ASTM G48 pitting test at a defined temperature. For demanding seawater work a super duplex grade such as 1.4410 is the safer specification.

How is 1.4460 machined?

Slowly and rigidly. Although hardness is capped at 260 HBW, the two-phase structure work-hardens rapidly and thermal conductivity of 15 W/(m·K) keeps the cutting heat at the tool tip. Use positive rake coated carbide or high-grade high-speed steel, rigid clamping and generous flood coolant, and never allow the tool to dwell or rub. Take fewer, deeper passes rather than many light ones, so each cut starts below the work-hardened layer left by the last. Asking for proof-machined material means the first cut starts below the as-forged skin.

What certificates are supplied with 1.4460 forgings?

EN 10204 3.1 material certificates as standard, covering heat number, chemical analysis, mechanical test results and heat-treatment records. EN 10204 3.2 witnessed by a classification society or an inspection body such as SGS or TÜV is available on request. Duplex-specific testing including ASTM A923 phase balance, ferrite counting, ASTM G48 pitting and ASTM A262 or G28 intergranular corrosion is placed with an accredited third-party laboratory and reported alongside the mill certificate. The works holds CCS, BV, DNV, LR and NK classification society approvals.

What is the minimum order quantity and lead time for 1.4460 forgings?

Minimum order is 10 kg with no minimum piece count, so 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. Duplex grades sit toward the middle of that range because the forging schedule allows for reheats and the solution anneal and quench cycle cannot be rushed. Third-party witnessed inspection and outside corrosion testing need scheduling, so flag both at enquiry stage to have them built into the quoted date rather than added to it.

Who supplies 1.4460 forgings?

Jiangyin Jiangnan Metal Co., Ltd. is an integrated steel melting works and open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, operating since 1997. It melts duplex grades in-house through the electric arc furnace, ladle furnace and vacuum oxygen decarburisation route, so nitrogen is set at the furnace rather than inherited from purchased billet, and forges 1.4460 into bars, seamless rolled rings to 6,000 mm outside diameter, flanges, discs, tube sheets, valve parts and shafts to drawing. Contact +86 189 2135 9659 or sales@steelforgepieces.com. Quotations within two working days.

Standards referenced on this page

  • EN 10088-1, Stainless steels, Part 1: List of stainless steels
  • EN 10088-3:2014, Stainless steels, Part 3: Technical delivery conditions for semi-finished products, bars, rods, wire, sections and bright products of corrosion resisting steels for general purposes
  • EN 10250-4, Open die steel forgings for general engineering purposes, Part 4: Stainless steels
  • EN 10204, Metallic products, types of inspection documents
  • EN 10020, Definition and classification of grades of steel
  • ISO 15510, Stainless steels, chemical composition
  • ASTM A240/A240M, Chromium and chromium-nickel stainless steel plate, sheet and strip for pressure vessels and for general applications
  • ASTM A182/A182M, Forged or rolled alloy and stainless steel pipe flanges, forged fittings, valves and parts for high-temperature service
  • ASTM A923, Detecting detrimental intermetallic phase in duplex austenitic/ferritic stainless steels
  • ASTM G48, Pitting and crevice corrosion resistance of stainless steels and related alloys by use of ferric chloride solution
  • ASTM E562, Determining volume fraction by systematic manual point count

Page last reviewed 22 September 2026 by Jiangyin Jiangnan Metal Co., Ltd.

Values on this page are indicative and drawn from the standards listed above. They do not replace the current edition of the applicable standard or design code. Confirm all design values against the governing code for your project before use.

Need 1.4460 duplex forgings?

Send your drawing and we will quote weight, price and lead time within two working days. Minimum order 10 kg.

Request a quote