EN 10088-2 X1NiCrMoCu25-20-5 1.4539 Stainless Steel Plate

EN 10088-2 X1NiCrMoCu25-20-5 1.4539 stainless steel plate is a high-alloy austenitic flat product supplied to EN 10088-2, the European standard for stainless steel sheet, plate and strip for general purposes. X1NiCrMoCu25-20-5 contains up to 0.020 % carbon, 19.0 – 21.0 % chromium, 24.0 – 26.0 % nickel, 4.0 – 5.0 % molybdenum and 1.20 – 2.00 % copper, with tighter limits on phosphorus (0.030 %) and sulphur (0.010 %) than the 300-series grades. Copper and molybdenum together give the grade its resistance to sulphuric and phosphoric acids. It corresponds to the 904L type. EN 10088-2 lists 1.4539 as a standard grade, as cold rolled strip up to 8 mm, continuously hot rolled strip up to 13.5 mm and hot rolled plate up to 75 mm, solution annealed. Table 7 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 high-alloy austenitic hot rolled plate, coil and cold rolled sheet. 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 1.4539 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 X1NiCrMoCu25-20-5 sheet and plate from China, and how SHH STEEL deals with each of them.

1.4539 is the EN counterpart of UNS N08904, Type 904L, in ASTM A240 (see ASTM A240 Type 904L sheet and plate). ASTM A240-22 notes that 904L is a common name, not a trademark, and not associated with any one producer. For pressure equipment the grade is ordered to EN 10028-7; see EN 10028-7 1.4539 pressure vessel plate.

The EN ranges for chromium, nickel and copper lie inside the ASTM ranges, and EN also has tighter phosphorus, sulphur and silicon limits. The one point to check is nitrogen: EN allows up to 0.15 %, ASTM only 0.10 %, so a dual-certified heat needs nitrogen at most 0.10 %. SHH STEEL checks this when a buyer needs dual certification.

1.4539 is also listed in EN 10028-7:2016 for pressure purposes. 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 1.4539 chemical composition below is the cast (heat) analysis from EN 10088-2:2014 Table 1. Values are percentages by mass; a single figure is a maximum.

The 1.4539 nickel of 24.0 – 26.0 % and the 1.4539 copper content of 1.20 – 2.00 % are what separate it from the 317-type grades. Phosphorus (0.030 %) and sulphur (0.010 %) limits are tighter than for the 300-series grades. SHH STEEL checks nickel, molybdenum, copper and carbon on every certificate as part of the 1.4539 chemical composition review.

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. Chromium uses ± 0.20 % at the 19.0 % minimum and ± 0.25 % at the 21.0 % maximum, because Table 5 changes band at 20.0 %. If a product analysis is required, it should be stated in the order together with the Table 5 tolerances.

The 1.4539 mechanical properties below are the room-temperature values from EN 10088-2:2014 Table 7 for austenitic steels in the solution annealed condition. Test pieces are transverse; the A80 elongation applies below 3 mm and the proportional elongation A from 3 mm.

Rp1.0 values are for guidance only. For continuously hot rolled products, 20 MPa higher minimum Rp0.2 and 10 MPa higher Rp1.0 may be agreed. For strip in rolling widths below 300 mm tested longitudinally, the minimum proof strength is reduced by 15 MPa and elongation by 5 % (constant gauge) or 2 % (proportional gauge). For bigger sizes than those listed, mechanical values are to be agreed.

Table 7 rates 1.4539 resistance to intergranular corrosion (EN ISO 3651-2) as “yes” in both the delivery condition and the sensitized condition.

Cold worked condition (process route 2H)

EN 10088-2 Tables 19 and 20 list no cold worked (2H) strength levels for 1.4539, so the grade is ordered in the solution annealed condition (+AT). Where higher annealed strength is needed, the nitrogen-alloyed 1.4529 is the related option.

Minimum proof strength at elevated temperature (EN 10088-2 Table 12, +AT)

EN 10088-2 Table 12 gives values from 100 °C to 550 °C for this grade, for the solution annealed condition (+AT). They are minimum values for design and are not tested unless agreed.

EN 10088-2 Table A.1 gives the following guideline temperatures for 1.4539:

The footnotes to Table A.1 state that with a continuous furnace the upper part of the range is usually preferred or even exceeded, and that the lower end of the range should be aimed at when the heat treatment is part of further processing, because otherwise the mechanical properties may be affected. Solution annealing may be omitted if hot working and cooling achieve the required mechanical properties and resistance to intergranular corrosion.

The Euro Inox tables give the same 1 060 – 1 140 °C range with cooling in air or water. This is higher than the 1 030 – 1 110 °C used for the 316L grades. Material is delivered as +AT.

The values below are approximate reference figures for X1NiCrMoCu25-20-5 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 1.4539 a density of 8.0 g/cm³; the EN 10088-1 extract by Häuselmann gives 8.1 g/cm³, so weight calculations should state which value is used. Both give a modulus of 195 GPa, a thermal conductivity of 12 W/(m·K) and an electrical resistivity of 1.00 Ω·mm²/m. The Häuselmann table lists 1.4539 as not magnetisable, with the note that small amounts of ferrite and/or martensite from cold working increase magnetisability.

The Euro Inox fabrication tables list 1.4539 for flue gas desulphurisation, parts exposed to condensates of combustion gases and building fasteners in aggressive atmospheres. They describe high resistance to sulphuric and phosphoric acid, to pitting corrosion and to stress corrosion cracking, and resistance to intergranular corrosion in continuous service up to 400 °C. EN 10088-2 Table 7 rates its resistance to intergranular corrosion, tested to EN ISO 3651-2, as “yes” in the delivery condition and “yes” in the sensitized condition.

Where more resistance to chlorides is needed, the 6 % molybdenum grades EN 10088-2 1.4529 plate and EN 10088-2 1.4547 plate are the next step; where 4 – 5 % molybdenum without high nickel is enough, EN 10088-2 1.4439 plate.

As EN 10088-2 notes, corrosion resistance depends strongly on the environment and cannot always be judged from laboratory tests, so experience with the grade in similar service should be used.

1.4539 is weldable by the common arc and resistance processes; as a fully austenitic, highly alloyed grade, filler choice and heat input need attention.

• The Euro Inox fabrication tables rate TIG/MIG, manual metal arc and resistance welding as suitable for 1.4539; they give no rating for autogenous welding.
• Filler materials listed include the matching 1.4539 and 1.4519, and the nickel alloys 2.4831 and 2.4656.
• EN 10088-2 Table 7 rates 1.4539 “yes” for intergranular corrosion after sensitization.
• EN 10088-2 does not specify welding procedures; these are published guidelines and general practice.

These points reflect industry practice for high-alloy austenitic stainless steels rather than requirements of EN 10088-2, which does not specify welding procedures. In the SHH STEEL workshop, blanks and slit strips are cut with clean, burr-free edges so that seam, spot and tube welding run without edge preparation problems.

Annealed 1.4539 forms with standard austenitic practice and work-hardens during forming. Its minimum elongation of 35 % is lower than that of the 316L grades, so bend radii and forming steps should be checked for heavy forming.

Thick plate is cut by plasma or waterjet, and sheet by laser or shearing. Machining needs sharp tools and positive feeds to avoid work hardening at the cut.

We run our own workshop next to the warehouse, so 1.4539 hot rolled plate and X1NiCrMoCu25-20-5 plate blanks can be delivered cut to size, laser-cut or bent, with protective film on visible surfaces. Details are on our steel cutting services and bending and forming services pages.

1.4539 is listed in EN 10088-2 as cold rolled strip, continuously hot rolled strip and hot rolled plate, all solution annealed.

EN 10088-2 Table 7 gives mechanical values for hot rolled plate up to 75 mm; for bigger sizes the mechanical values shall be agreed at the time of enquiry and order. Under section 6.9 of the standard, EN ISO 18286 normally applies only to individually rolled quarto plate, while continuously rolled material follows EN ISO 9444-2.

SHH STEEL can supply 1.4539 hot rolled plate and 1.4539 cold rolled sheet, in standard sizes or cut to your drawing.

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.

The No.1, No.4 and BA cross-references follow worldstainless and IMOA comparison tables; EN 10088-2 itself defines only the EN symbols, and not every route is available for every grade. Special finishes such as 1J and 2J apply to one surface unless otherwise agreed. The Euro Inox tables rate 1.4539 polishability as good.

The usual 1.4539 equivalent, and the answer to most 904L equivalent enquiries, is UNS N08904.

For Chinese pressure vessels the grade is ordered as GB/T 713.7 S39042 pressure vessel plate. The foreign grades allow wider chromium and nickel ranges and higher phosphorus and sulphur, so a heat to those standards does not automatically meet 1.4539.

1.4539 vs 1.4439 and 1.4529

Compared with 1.4439, 1.4539 has the same 4.0 – 5.0 % molybdenum but about twice the nickel (24.0 – 26.0 % against 12.5 – 14.5 %), more chromium and a copper addition, which the Euro Inox tables link to resistance to sulphuric and phosphoric acid; 1.4439 has higher proof strength from nitrogen. Compared with 1.4529, it has less molybdenum (4.0 – 5.0 % against 6.0 – 7.0 %) and no nitrogen addition.

Typical applications of 1.4539 plate and sheet listed in the Euro Inox fabrication tables include:

• Flue gas desulphurisation plant
• Parts exposed to condensates of combustion gases
• Building fasteners in aggressive atmospheres
• Equipment handling sulphuric and phosphoric acid
• Pressure parts (to EN 10028-7)

For pressure equipment, 1.4539 plate is ordered to EN 10028-7; for other uses, EN 10088-2 applies.

Buyers choose 1.4539 when 316L or 317L types corrode in acid or chloride service. SHH STEEL can advise when a 6 % molybdenum grade should be compared. For still more nickel and chromium, EN 10088-2 1.4563 plate (26.0 – 28.0 % chromium, 30.0 – 32.0 % nickel, 3.0 – 4.0 % molybdenum) is the related EN 10088-2 grade.

For 1.4539 the main risks are nickel or copper below the EN minimums, nitrogen above the ASTM limit on dual-certified orders, and wrong filler metal.

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 1.4539 order is supported by documents and checks that make the material traceable to the heat:

• Cast analysis with nickel, chromium, molybdenum, copper and carbon checked
• Tensile test (transverse) to Table 7
• Impact test for plate over 10 mm when agreed
• Intergranular corrosion test to EN ISO 3651-2 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 acid plant, flue gas and chemical 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: 6 plates, 10 mm × 2 000 mm × 6 000 mm, EN ISO 18286, EN 10088-2, steel X1NiCrMoCu25-20-5 (1.4539), 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. 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 1.4539 and related high-alloy austenitic 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 1.4539 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 X1NiCrMoCu25-20-5 1.4539 is the 904L-type high-alloy austenitic steel with copper, supplied as hot rolled plate up to 75 mm and cold rolled sheet for sulphuric and phosphoric acid, flue gas and chemical 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.