EN 10088-2 X2CrNiMoN17-13-5 1.4439 Stainless Steel Plate

EN 10088-2 X2CrNiMoN17-13-5 1.4439 stainless steel plate is a low-carbon, nitrogen-alloyed austenitic flat product supplied to EN 10088-2, the European standard for stainless steel sheet, plate and strip for general purposes. X2CrNiMoN17-13-5 contains up to 0.030 % carbon, 16.5 – 18.5 % chromium, 12.5 – 14.5 % nickel, 4.0 – 5.0 % molybdenum and 0.12 – 0.22 % nitrogen. It has the highest molybdenum of the 17 – 18 % chromium austenitic grades in EN 10088-2, and the nitrogen raises its proof strength to 270 MPa for plate. It corresponds to the 317LMN type. EN 10088-2 lists 1.4439 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 austenitic CrNiMo hot rolled plate 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 1.4439 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 X2CrNiMoN17-13-5 sheet and plate from China, and how SHH STEEL deals with each of them.

1.4439 is the EN counterpart of UNS S31726, Type 317LMN, in ASTM A240 (see AISI 317LMN stainless steel plate). For pressure equipment it is ordered to EN 10028-7; see EN 10028-7 1.4439 pressure vessel plate.

The molybdenum ranges are the same, but chromium, nickel and nitrogen only overlap: a heat can meet both 1.4439 and S31726 with chromium of 17.0 – 18.5 %, nickel of 13.5 – 14.5 %, nitrogen of 0.12 – 0.20 % and silicon at most 0.75 %. SHH STEEL checks these overlaps when a buyer needs dual certification.

1.4439 is also listed in EN 10028-7:2016 for pressure purposes, as is the lower-molybdenum 1.4429 (EN 10028-7 1.4429 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 1.4439 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 1.4439 molybdenum of 4.0 – 5.0 % and nitrogen of 0.12 – 0.22 % are what separate it from 1.4438 and the 316L grades. Footnote b to Table 1 permits controlled sulphur ranges: 0.015 – 0.030 % for machinability, 0.008 – 0.015 % for weldability, and 0.015 % max. for polishability. SHH STEEL checks molybdenum, nitrogen and carbon on every certificate as part of the 1.4439 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. If a product analysis is required, it should be stated in the order together with the Table 5 tolerances.

The 1.4439 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 1.4439 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 1.4439, so the grade is ordered in the solution annealed condition (+AT). Its nitrogen content already gives a higher annealed proof strength than the 316L grades.

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

EN 10088-2 Table 12 gives values for 1.4439 from 100 °C to 400 °C only, for the solution annealed condition (+AT); no values are given above 400 °C. They are minimum values for design and are not tested unless agreed.

EN 10088-2 Table A.1 gives the following guideline temperatures for 1.4439:

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 X2CrNiMoN17-13-5 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 EN 10088-1 table as reproduced by Häuselmann lists 1.4439 as not magnetisable, with the note that small amounts of ferrite and/or martensite formed by cold working increase magnetisability. It gives a modulus of 200 GPa at 20 °C falling to 186 GPa at 200 °C, a thermal conductivity of 14 W/(m·K) and an electrical resistivity of 0.85 Ω·mm²/m.

The Euro Inox fabrication tables list 1.4439 for the chemical industry, seawater desalination and flue gas cleaning, and describe high corrosion resistance at elevated temperatures and higher chlorine concentrations, at temperatures of up to 400 °C in continuous service. 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. Its molybdenum minimum of 4.0 % is the highest among the 17 – 18 % chromium austenitic grades in the standard.

Where 3.0 – 4.0 % molybdenum is enough, EN 10088-2 1.4438 plate is the lower-alloyed step; for 2.00 – 2.50 % molybdenum with nitrogen, EN 10088-2 1.4406 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.

1.4439 is weldable by the common arc and resistance processes, with filler choice being the key point.

• The Euro Inox fabrication tables rate TIG/MIG, manual metal arc and resistance welding as suitable for 1.4439; they give no rating for autogenous welding.
• Filler materials listed are 1.4440, 1.4439, 1.4453 and 1.4519, and the nickel alloys 2.4831 and 2.4656.
• EN 10088-2 Table 7 rates 1.4439 “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 austenitic CrNiMo 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 1.4439 forms with standard austenitic practice, but its higher proof strength and lower minimum elongation (35 – 40 %) mean more forming force and springback than for 1.4404. EN 10088-1 data note that cold forming can raise magnetisability slightly.

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 1.4439 hot rolled plate and X2CrNiMoN17-13-5 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.

1.4439 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 1.4439 hot rolled plate and 1.4439 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 1.4439 polishability as good.

The usual 1.4439 equivalent, and the answer to most 317LMN equivalent enquiries, is UNS S31726.

Both the ASTM and the GB grade require at least 13.5 % nickel and allow chromium up to 20 %, so a 1.4439 heat at the low end of its nickel range would not meet them.

1.4439 vs 1.4438 and 1.4406

Compared with 1.4438, 1.4439 has 4.0 – 5.0 % molybdenum against 3.0 – 4.0 %, adds 0.12 – 0.22 % nitrogen and has slightly less nickel; its plate proof strength is 270 against 220 MPa, and both are rated “yes” after sensitization. Compared with 1.4406, it has roughly double the molybdenum and more nickel, with a slightly lower proof strength (270 against 280 MPa).

Typical applications of 1.4439 plate and sheet listed in the Euro Inox fabrication tables include:

• Chemical industry equipment
• Seawater desalination plant
• Flue gas cleaning equipment
• Service at elevated temperatures and higher chlorine concentrations, up to 400 °C continuous
• Pressure parts (to EN 10028-7)

For pressure equipment, 1.4439 plate is ordered to EN 10028-7; for other uses, EN 10088-2 applies.

Buyers choose 1.4439 when 1.4438 or the 316L grades are not resistant enough to chlorides. SHH STEEL can advise when a duplex or super-austenitic grade should be compared.

For 1.4439 the main risks are molybdenum below 4.0 %, missing nitrogen, and certificates that only show 317LMN limits.

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 1.4439 order is supported by documents and checks that make the material traceable to the heat:

• Cast analysis with molybdenum, nitrogen, nickel 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 flue gas, desalination 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, 8 mm × 2 000 mm × 6 000 mm, EN ISO 18286, EN 10088-2, steel X2CrNiMoN17-13-5 (1.4439), 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 1.4439 and related 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 1.4439 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 X2CrNiMoN17-13-5 1.4439 is the 317LMN-type austenitic steel with 4.0 – 5.0 % molybdenum and nitrogen, supplied as hot rolled plate up to 75 mm and cold rolled sheet for flue gas, desalination 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.