X2CrNiMoN22-5-3 (1.4462) Duplex Stainless Steel Forgings

Jiangyin Jiangnan Metal Co., Ltd. melts, forges, heat-treats and machines X2CrNiMoN22-5-3, EN material number 1.4462, at one works in Jiangyin, Jiangsu. Forms include seamless rolled rings, forged rings, flanges, shafts, round bars, discs, tube sheets, sleeves, bushings, hollow cylinders and valve components, supplied solution annealed to EN 10088-3, EN 10250-4 or EN 10222-5 with EN 10204 3.1 or 3.2 certification.

Data checked against EN 10088-3 requirements for solution-annealed long products. Updated 9 October 2026. Plain-text version: X2CrNiMoN22-5-3.md.

What X2CrNiMoN22-5-3 is

X2CrNiMoN22-5-3 is the EN 10088 steel name for material number 1.4462, a nitrogen-alloyed austenitic-ferritic stainless steel. The name describes the chemistry. X marks a high-alloy steel, the figure 2 stands for a carbon content of about 0.02 to 0.03 %, the figures 22-5-3 give the nominal chromium, nickel and molybdenum contents in percent, and N denotes the deliberate nitrogen addition.

The structure is roughly half ferrite and half austenite. That balance gives a 0.2 % proof strength of at least 450 MPa, about twice the figure for a standard austenitic grade such as 1.4404 (316L), while the chromium, molybdenum and nitrogen together provide resistance to chloride pitting, crevice attack and chloride stress corrosion cracking. For a forging buyer the higher proof strength often allows a thinner section at the same design pressure, which offsets part of the price premium over 316L.

The limit on the grade is temperature. Duplex steels must not be held in the band where intermetallic phases form, so 1.4462 is used at ambient and moderate temperatures rather than in hot service. Published data sheets for the grade give a usable range of -100 °C to 250 °C.

Designations and equivalents

Standards covering 1.4462

1.4462 runs across the EN stainless product standards, and the governing part depends on the product form rather than on the alloy. For forged products the three that usually apply are EN 10088-3, EN 10250-4 and EN 10222-5.

Chemical composition

Nitrogen is the element that needs the closest control. It stabilises austenite, raises the proof strength and contributes heavily to pitting resistance, and it is also the element most readily lost during melting. Stainless and duplex heats at this works are refined under vacuum oxygen decarburisation, the route used to bring carbon down while holding nitrogen inside the specified band. Because the steel is melted here, chemistry is verified at the furnace by optical emission spectrometry rather than taken from a billet supplier's certificate.

Mechanical properties

Long products to EN 10088-3, solution annealed

Flat products to EN 10088-2, for comparison

Cold rolled strip carries the highest proof strength because the finishing passes leave a controlled amount of cold work in the material, and its minimum elongation is lower as a result. These flat-product figures are given because fabricated assemblies often combine forged nozzles and flanges with plate shells, and both sets of numbers are needed at the design stage.

Physical properties

Thermal expansion of duplex sits closer to carbon steel than austenitic stainless does. That simplifies dissimilar-metal joints in process pipework and reduces differential expansion in bolted flange assemblies.

Corrosion resistance and PREN

Pitting resistance is ranked by the pitting resistance equivalent number, PREN = %Cr + 3.3 × %Mo + 16 × %N. Across the full EN composition range 1.4462 gives a PREN of 30.9 to 38.0, with a typical value around 34. Where a project calls for a minimum PREN of 34 or 35, the heat has to be aimed at the upper part of the chromium, molybdenum and nitrogen ranges. That is a melting decision and cannot be corrected downstream, which is the main reason the in-house melt shop is relevant on this grade.

In service the grade is resistant to intergranular corrosion in the delivered condition, and the low carbon content keeps that resistance after welding. It performs well in chloride-bearing media and against organic and phosphoric acids, resists stress corrosion cracking far better than 304 or 316, and is resistant to seawater at room temperature. Concentrated chlorides, chlorides combined with raised temperature, and crevice geometries are the conditions where pitting can still start, so temperature and chloride concentration should be confirmed before 1.4462 is chosen over a super-duplex grade such as A182 F55 or A182 F53.

Forging and heat treatment

1.4462 is moderately forgeable and has a narrower working window than carbon or alloy steel, so the thermal schedule governs the result more than press capacity does.

The quench decides whether a heavy duplex forging passes its phase-balance test. A 300 mm ring section cannot be cooled through the sigma-forming range at the rate a 50 mm bar achieves, so quench tank capacity, charge spacing and the time between furnace door and water are written into the route card rather than left to the operator. Fourteen heat-treatment furnaces on site allow the solution treatment to be scheduled around the part.

Machining and welding

Duplex machines poorly compared with austenitic stainless. It work-hardens quickly and loads tooling heavily. Practical measures are rigid setups, coated carbide, reduced surface speed against 316L, a shallower depth of cut and generous coolant. Feed rates should be reduced only slightly: cutting too light a feed lets the tool rub instead of cut, which glazes the surface and shortens tool life. Parts can be supplied as forged with machining allowance, proof machined for volumetric inspection, or finish machined to drawing.

For welding, 1.4462 suits most common arc processes including MMA, TIG and laser welding, but not gas welding. Heat input in the region of 1 to 3 kJ/mm is recommended, because both very low and very high heat input disturb the ferrite and austenite balance in the weld and heat-affected zone. ASTM A182 does not permit weld repair of F51 forgings, and the same rule is applied to duplex forgings supplied under EN designations unless a customer specification states otherwise.

Product forms in X2CrNiMoN22-5-3

Where X2CrNiMoN22-5-3 forgings are used

1.4462 is specified where chlorides, moderate H₂S or aggressive process chemistry rule out 304 and 316, and where the higher proof strength lets the designer reduce section thickness.

• Oil and gas, offshore and subsea. Topside and subsea flanges, manifolds, wellhead and Christmas tree components, spools, riser parts and downhole components for moderately sour wells.
• Seawater handling and desalination. Firewater and cooling water flanges, injection systems, high-pressure reverse osmosis connections, separator and heat exchanger parts.
• Chemical and petrochemical plant. Pressure vessel flanges, tube sheets, covers, reactor nozzles, crystalliser equipment, pump and valve parts in brine and chloride-bearing acid service.
• Pulp and paper. Digesters, liquor tanks, bleach plant components, paper machine rolls and shafts.
• Power generation and rotating equipment. Turbine and gas compressor parts, gearbox components, industrial air compressors and nitrogen generators.
• Shipbuilding and marine. Propeller and rudder components, couplings and deck hardware, covered by CCS, BV, DNV, LR and NK approvals.
• Heavy machinery. Gear blanks, pinion shafts, forged rolls, wheels and slewing rings.

Testing, inspection and certification

Sour service

22Cr duplex of the S31803 and S32205 type is covered by NACE MR0175 / ISO 15156-3, which sets a required phase balance in the region of 35 to 65 % ferrite together with limits on H₂S partial pressure, chloride content and temperature. The limits that apply, and the hardness acceptance criteria used on the finished part, depend on the material data sheet the project invokes. Send the H₂S partial pressure, chloride level and service temperature with the enquiry and the applicable limits will be confirmed in writing before the order is accepted.

Manufacturing capability

Most forging suppliers in China buy billet. This works starts at the furnace, which on a nitrogen-alloyed duplex grade is the difference between aiming the chemistry at a PREN target and accepting whatever the purchased billet happens to hold.

Questions and answers