EN 10088-2 X2CrNiMoCuWN25-7-4 1.4501 Stainless Steel Plate

EN 10088-2 X2CrNiMoCuWN25-7-4 1.4501 stainless steel plate is a super duplex (austenitic-ferritic) flat product supplied to EN 10088-2, the European standard for stainless steel sheet, plate and strip for general purposes. X2CrNiMoCuWN25-7-4 contains up to 0.030 % carbon, 24.0 – 26.0 % chromium, 6.0 – 8.0 % nickel, 3.0 – 4.0 % molybdenum, 0.20 – 0.30 % nitrogen, and 0.50 – 1.00 % each of copper and tungsten. It is the composition known as UNS S32760. EN 10088-2 places 1.4501 among its special grades, defined as grades for special use and/or with limited availability, and Table 8 lists it as hot rolled plate (P) up to 75 mm only, solution annealed, with a minimum proof strength of 530 MPa. Table 8 rates it resistant to intergranular corrosion both as delivered and after sensitization.

SHH STEEL works as a steel sourcing partner with long-term relationships with Chinese stainless mills that roll duplex and super duplex hot rolled plate. For large tonnages, the buyer can contract directly with a suitable mill, with SHH STEEL assisting for a modest service fee and handling follow-up and documents. For small orders we consolidate demand, so that 1 – 5 t lots are placed against genuine mill production instead of stock of unknown origin. Each shipment can be released after third-party inspection by TUV, ABS, BV, DNV, CCS or an agency the buyer nominates, and payment by TT or LC is accepted. The rest of this page covers the technical side of EN 10088-2 1.4501 and the steps we take so that the sheet that arrives is the sheet that was ordered.

The table below lists the concerns buyers raise most often when sourcing EN 10088-2 X2CrNiMoCuWN25-7-4 sheet and plate from China, and how SHH STEEL deals with each of them.

1.4501 corresponds to UNS S32760 in ASTM A240-22, which lists the grade without a type name. The composition is best known as ZERON 100, a registered trademark of Rolled Alloys, whose data sheet names both UNS S32760 and EN 1.4501 and lists EN 10088-2 and EN 10028-7 among its specifications. SHH STEEL orders and certifies by EN steel number and UNS number; a specific producer’s branded product has to be named and agreed in the order. For pressure equipment the grade is ordered to EN 10028-7; see EN 10028-7 1.4501 pressure vessel plate.

The alloying ranges are identical. ASTM is tighter only on phosphorus and sulphur, and A240-22 footnote K requires Cr + 3.3 (Mo + ½ W) + 16 N of at least 41. At the EN minimums this sum is only about 37.9, so a dual-certified heat needs phosphorus of at most 0.030 %, sulphur of at most 0.010 % and enough chromium, molybdenum, tungsten and nitrogen to reach 41. The IMOA guide gives a minimum annealing temperature of 1 100 °C for S32760, so dual-certified plate is annealed at 1 100 – 1 120 °C, the top of the EN range. SHH STEEL checks this when a buyer needs dual certification.

1.4501 is also listed in EN 10028-7:2016 for pressure purposes, together with 1.4410 (EN 10028-7 1.4410 pressure vessel plate) and 1.4507 (EN 10028-7 1.4507 pressure vessel plate). That standard may set its own test and property requirements, which we have not reproduced here.

Edition note: the values on this page are taken from EN 10088-2:2014. A revised edition (EN 10088-2:2024) has since been published. If your contract names the newer edition, SHH STEEL checks the order against that text before production, and any difference is raised at the quotation stage rather than after rolling.

The 1.4501 chemical composition below is the cast (heat) analysis from EN 10088-2:2014 Table 2. Values are percentages by mass; a single figure is a maximum.

The 1.4501 chemical composition adds 0.50 – 1.00 % each of copper and tungsten to a super duplex base, and limits manganese to 1.00 %. Table 2 gives 1.4501 no PRE footnote, so a minimum PRE has to be agreed in the order if required. SHH STEEL checks chromium, molybdenum, nickel, nitrogen, copper and tungsten on every certificate and calculates the PRE from the cast analysis.

Product analysis tolerances (EN 10088-2 Table 5)

A product analysis is a check made on the delivered sheet. It is not mandatory under EN 10088-2; it is carried out when agreed at the time of enquiry and order, and SHH STEEL can arrange it through a partner laboratory. The permissible tolerances on the cast limits are:

Where several product analyses are made on one cast, individual results may exceed the maximum or fall below the minimum, but not both for the same element. Copper (up to 1.00 %) and tungsten (up to 3.00 %) have plus-only tolerances in Table 5, so their minimums do not change. If a product analysis is required, it should be stated in the order together with the Table 5 tolerances.

The 1.4501 mechanical properties below are the room-temperature values from EN 10088-2:2014 Table 8 for austenitic-ferritic steels in the solution annealed condition. Proof strength applies to transverse test pieces; elongation applies to longitudinal and transverse test pieces, with A80 below 3 mm and the proportional elongation A from 3 mm.

Table 8 gives no 1 % proof strength: under section 7.4.2 of EN 10088-2 the 1 % proof strength is determined for austenitic steels only. For bigger sizes than those listed, mechanical values are to be agreed at the time of enquiry and order.

EN 10088-2 lists 1.4501 as hot rolled plate only. Table 8 rates its resistance to intergranular corrosion (EN ISO 3651-2) as “yes” in both the delivery condition and the sensitized condition. Rolled Alloys’ ZERON 100 data sheet gives a minimum yield strength of 80 ksi (about 550 MPa) for its product, above the EN minimum.

Cold worked condition (process route 2H)

EN 10088-2 Tables 19 and 20 list no cold worked (2H) strength levels for 1.4501, or for any other austenitic-ferritic grade, so it is ordered in the solution annealed condition (+AT). Its annealed plate proof strength is already 530 MPa.

Minimum 0.2 % proof strength at elevated temperature (EN 10088-2 Table 13, +AT)

Table 13 gives values only from 100 °C to 250 °C, and only for the 0.2 % proof strength. These are the same values as for 1.4410 and 1.4507. The IMOA “Practical Guidelines for the Fabrication of Duplex Stainless Steels” (3rd edition) explains that alpha prime forms in the ferrite below about 525 °C, causing 475 °C embrittlement that is most pronounced in the molybdenum-containing grades.

EN 10088-2 Table A.2 gives the following guideline temperatures for 1.4501:

The footnotes to Table A.2 state that solution annealing temperatures shall be agreed for simulated heat-treated test pieces, that with a continuous furnace the upper part of the range is usually preferred or even exceeded, and that cooling must be rapid enough to avoid precipitation.

According to the IMOA “Practical Guidelines for the Fabrication of Duplex Stainless Steels” (3rd edition), postweld stress relief is not needed for duplex grades and is likely to be harmful, because it may precipitate intermetallic phases (700 – 1 000 °C) or alpha prime (around 475 °C); where a heat treatment is needed, it should be a full solution anneal followed by water quenching.

The IMOA guide gives a hot-forming range of 1 230 – 1 000 °C and a minimum soaking temperature of 1 100 °C for S32760, and a minimum annealing temperature of 1 100 °C. EN 10088-2 Table A.2 is a guideline; for dual-certified plate the anneal is therefore set at the top of the EN range. Material is delivered as +AT.

The values below are approximate reference figures for X2CrNiMoCuWN25-7-4 at room temperature, from the worldstainless “Tables of Technical Properties”, which follow EN 10088-1. They are suitable for design estimates and weight calculation; where a figure is critical, use EN 10088-1 itself.

The worldstainless table gives 1.4501 a density of 7.8 g/cm³, a modulus of 200 GPa, a thermal expansion of 13.5 × 10⁻⁶ /K (20 – 200 °C), a thermal conductivity of 15 W/(m·K), a specific heat of 500 J/(kg·K) and an electrical resistivity of 0.80 Ω·mm²/m, with no 20 – 400 °C expansion value reported, and lists it under the ferromagnetic grades. The IMOA guide notes that all duplex stainless steels are ferromagnetic because of their ferrite.

Rolled Alloys’ ZERON 100 data sheet describes resistance to pitting and crevice corrosion in warm seawater with a guaranteed PREN above 40, resistance to stress corrosion cracking in chloride and sour environments, and resistance to sulphuric acid, which it attributes to the copper. The 1.4501 PREN, calculated as Cr + 3.3 (Mo + ½ W) + 16 N, is about 37.9 at the minimum of the EN ranges; ASTM A240 requires at least 41 for S32760, and the IMOA guide gives a PREN range of 40 – 43. EN 10088-2 Table 8 rates its resistance to intergranular corrosion, tested to EN ISO 3651-2, as “yes” in the delivery condition and “yes” in the sensitized condition.

Without copper and tungsten, the nearest EN super duplex is EN 10088-2 1.4410 plate; with more copper and no tungsten, it is EN 10088-2 1.4507 plate. The standard duplex EN 10088-2 1.4462 plate is the usual step down where super duplex resistance is not needed.

As NOTE 2 to section 6.4 of EN 10088-2 points out, corrosion resistance depends strongly on the environment and cannot always be clearly ascertained through laboratory tests, so experience with the grade in similar service should be used.

1.4501 is welded with the practices used for other super duplex grades. The Euro Inox welding table lists 1.4501 as one of the filler materials for 1.4462 but gives no row for 1.4501 itself, so the guidance below comes from the IMOA duplex guide and the producer.

• The IMOA guide limits the interpass temperature to 100 °C for super duplex grades and does not recommend preheating, except about 100 °C to remove moisture.
• For joints between super duplex grades, IMOA Table 16 lists AWS E2594 consumables; Rolled Alloys names its own ZERON 100X filler for its product.
• Very high heat input risks intermetallic phases, while very low heat input leaves an excessively ferritic weld.
• EN 10088-2 Table 8 rates 1.4501 “yes” for intergranular corrosion after sensitization; EN 10088-2 does not specify welding procedures.

These points reflect industry practice for super duplex (austenitic-ferritic) stainless steels rather than requirements of EN 10088-2, which does not specify welding procedures. In the SHH STEEL workshop, plate blanks are cut with clean, burr-free edges, ready for the fabricator’s own joint preparation.

Annealed 1.4501 plate has at least 25 % elongation in Table 8, but its proof strength of 530 MPa is well above that of 1.4462. The IMOA guide notes that the higher strength of duplex steels means higher forming forces and larger springback in bending than for austenitic grades, and that shears and slitters need more power: the maximum thickness of 2304 or 2205 that can be sheared on a given machine is about 75 % of that for Type 304 or 316, and about 65 % for super duplex. Plasma and laser cutting use the same equipment as for austenitic steels, with a narrow heat-affected zone of about 0.25 mm that is removed by normal weld preparation. Machining is more demanding than for the 300-series grades, so rigid set-ups, sharp tools and generous coolant are recommended.

The IMOA guide notes that the more highly alloyed duplex grades with higher nitrogen are disproportionately more difficult to machine, and cautions that prolonged warm forming above about 315 °C can reduce ambient-temperature toughness and corrosion resistance.

We run our own workshop next to the warehouse, so 1.4501 plate and X2CrNiMoCuWN25-7-4 plate blanks can be delivered cut to size or bent. Details are on our steel cutting services and bending and forming services pages.

EN 10088-2 Table 8 lists 1.4501 only as hot rolled plate (P) up to 75 mm.

For bigger sizes than those listed, the mechanical values shall be agreed at the time of enquiry and order. Under section 6.9 of the standard, EN ISO 18286 applies to individually rolled quarto plate, and under section 6.7, ultrasonic testing of austenitic-ferritic flat products of 6 mm and over may be agreed to EN 10307.

SHH STEEL can supply 1.4501 super duplex plate in standard sizes or cut to your drawing, after confirming availability with the mill; sheet and strip have to be agreed separately.

Surface finish is ordered by the process route symbols of EN 10088-2 Table 6; trade names from ASTM and JIS are shown for reference. Not every route is available for every grade, and the mill confirms which ones it can supply.

EN 10088-2 Table 8 lists 1.4501 as hot rolled plate (P) only, so the cold rolled routes 2D, 2B and 2R are not part of the standard offer and would have to be agreed separately. The No.1 cross-reference follows worldstainless and IMOA comparison tables.

The usual 1.4501 equivalent is UNS S32760, so the 1.4501 S32760 pairing is the one used for dual certification.

Our GB/T 4237 page gives 022Cr25Ni7Mo4WCuN the same alloying ranges as S32760, with phosphorus up to 0.030 % and sulphur up to 0.010 %; for pressure equipment its GB counterpart is GB/T 713.7 S27603 pressure vessel plate. Equivalent grades are close but not identical, so the heat must meet every standard named on the order.

1.4501 vs 1.4410

On 1.4501 vs 1.4410: both have 24.0 – 26.0 % chromium and 6.0 – 8.0 % nickel, the same plate proof and tensile strength in Table 8 (530 MPa and 730 – 930 MPa), the same Table 13 values and the same Table A.2 temperatures. 1.4501 adds copper and tungsten, has less molybdenum (3.0 – 4.0 % against 3.0 – 4.5 %) and nitrogen (0.20 – 0.30 % against 0.24 – 0.35 %), and reaches 25 % against 20 % elongation. EN 10088-2 1.4410 plate is also listed as strip, while 1.4501 is plate only. ASTM sets a PRE minimum of 41 for both S32750 and S32760, counting tungsten for S32760.

Typical applications of 1.4501 plate named in Rolled Alloys’ ZERON 100 data sheet include:

• Seawater reverse osmosis desalination
• Heat exchangers
• Flue gas desulphurization (FGD) equipment
• Offshore oil and gas and sour gas service
• Sulphuric acid service

For pressure equipment, 1.4501 plate is ordered to EN 10028-7; for other uses, EN 10088-2 applies.

Rolled Alloys does not recommend its product for extended exposure above 600 °F (315 °C), because of a substantial loss of toughness; the IMOA guide gives the same 315 °C ASME limit for other super duplex grades.

For 1.4501 the main risks are a heat that meets EN but not the ASTM PRE of 41, 1.4410 supplied instead, phosphorus or sulphur above the ASTM limits, and intermetallic phases from slow cooling or high interpass temperature.

None of these steps is complicated, but they need to be agreed at the start. When you send an enquiry, tell us which of these points matters most to you, and the order will be built around it.

Every 1.4501 order is supported by documents and checks that make the material traceable to the heat:

• Cast analysis with chromium, molybdenum, tungsten, nickel, nitrogen and copper checked, and PRE calculated
• Tensile test (transverse) to Table 8
• Impact test for plate over 10 mm when agreed
• Intergranular corrosion test to EN ISO 3651-2, ferrite content or intermetallic-phase checks when agreed
• Thickness, flatness and surface inspection
• Additional checks through our third-party testing service: PMI, dimensional, flatness and surface inspection

If the order does not name an inspection document, EN 10088-2 requires only a test report 2.2. Because this is rarely enough for offshore, desalination and FGD equipment or export work, SHH STEEL supplies an EN 10204 3.1 inspection certificate as standard and a 3.2 certificate when an independent inspector (TUV, ABS, BV, DNV, CCS or an agency you nominate) witnesses testing and countersigns the document.

Ordering example and lead time

Following the pattern of the example in EN 10088-2, a typical order line would read: 4 plates, 20 mm × 2 000 mm × 6 000 mm, EN ISO 18286, EN 10088-2, steel X2CrNiMoCuWN25-7-4 (1.4501), process route 1D, inspection certificate 3.1 to EN 10204. Mill production lead time is generally 30 – 40 days from order confirmation, depending on the rolling schedule, the size and the tests requested; because 1.4501 is a special grade, the campaign date should be confirmed at enquiry. Consolidated small lots follow the same mill schedule, and we send progress updates at rolling, testing and packing.

• Mill relationships: long-term cooperation with Chinese stainless mills helps us secure competitive pricing and steadier delivery for 1.4501 and related duplex and super duplex grades.
• Direct mill contracts: for larger tonnages you can contract directly with a suitable mill, for a modest service fee, while we handle follow-up and documents.
• Order consolidation: 1 – 5 t lots are combined so they can be placed against genuine mill production.
• Own workshop: slitting, cut-to-length, laser cutting, bending and protective film before shipment.
• Inspection and certificates: third-party inspection by TUV, ABS, BV, DNV, CCS or your nominated agency, with EN 10204 3.1 or 3.2 certificates.
• Flexible payment: TT, LC or a combination of both.
• Port logistics: coil and sheet are packed seaworthy with heat-number labels and shipped through our worldwide shipping service, together with other grades if needed.

As a 1.4501 plate supplier SHH STEEL also stocks and sources the wider range of stainless steel sheets and plates, so mixed orders of different stainless grades can travel in one container with one set of paperwork.

EN 10088-2 X2CrNiMoCuWN25-7-4 1.4501 is the copper- and tungsten-alloyed super duplex special grade of the S32760 type, with a proof strength of 530 MPa, supplied as hot rolled plate up to 75 mm for offshore, desalination and FGD equipment. Choosing it is the easy part. Getting genuine material that matches the certificate, in the gauge and finish your parts need and on a predictable schedule, is where a sourcing partner earns its place, and that is the work SHH STEEL does every day through long-term mill cooperation, consolidation and its own workshop.

The next step is simple. Send SHH STEEL your drawing, or an enquiry with the quantity, thickness, width, finish and delivery destination, and we will judge whether a direct mill contract or consolidation with processing fits your order better, and quote accordingly. Send your sizes and quantities for a quotation.