EN 10088-2 X2CrNiMo18-15-4 1.4438 Stainless Steel Plate

EN 10088-2 X2CrNiMo18-15-4 1.4438 stainless steel plate is a low-carbon austenitic flat product supplied to EN 10088-2, the European standard for stainless steel sheet, plate and strip for general purposes. X2CrNiMo18-15-4 contains up to 0.030 % carbon, 17.5 – 19.5 % chromium, 13.0 – 16.0 % nickel and 3.0 – 4.0 % molybdenum, which puts it a step above the 316L grades in molybdenum. It corresponds to the 317L type. EN 10088-2 places 1.4438 among its special grades, defined as grades for special use and/or with limited availability, so sizes and lead time should be confirmed at enquiry. It is listed 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 1.4438 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 X2CrNiMo18-15-4 sheet and plate from China, and how SHH STEEL deals with each of them.

1.4438 is the EN counterpart of UNS S31703, Type 317L, in ASTM A240 (see ASTM A240 Type 317L sheet and plate). For pressure equipment it is ordered to EN 10028-7; see EN 10028-7 1.4438 pressure vessel plate.

The molybdenum ranges are the same, but chromium and nickel only overlap: a heat can meet both 1.4438 and S31703 with chromium of 18.0 – 19.5 %, nickel of 13.0 – 15.0 % and silicon at most 0.75 %. A 317L heat with less than 13.0 % nickel does not meet 1.4438. SHH STEEL checks these overlaps when a buyer needs dual certification.

1.4438 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 1.4438 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 1.4438 molybdenum of 3.0 – 4.0 % and nickel of 13.0 – 16.0 % are what separate it from 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, nickel and carbon on every certificate as part of the 1.4438 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 1.4438 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 1.4438 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 1.4438, so the grade is ordered in the solution annealed condition (+AT). Where a higher strength is needed, the nitrogen-alloyed 1.4439 is the usual options.

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 1.4438:

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 1 070 – 1 150 °C range with cooling in air or water. This is higher than the 1 030 – 1 110 °C used for the 316L grades, so mixed furnace loads should be avoided. Material is delivered as +AT.

The values below are approximate reference figures for X2CrNiMo18-15-4 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 1.4438 a slightly lower thermal conductivity (14 W/(m·K)) and higher electrical resistivity (0.85 Ω·mm²/m) than the 316L grades, reflecting its higher alloy content. 1.4438 is not listed in the EN 10088-1 extract by Häuselmann that we use for magnetic behaviour, so the magnetic statement above is the general austenitic one.

The Euro Inox fabrication tables list 1.4438 for containers and process equipment in the cellulose and textile industries. 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 3.0 % is higher than that of any 316L-type grade in the standard, which raises resistance to pitting and crevice corrosion in chloride media.

Where more molybdenum is needed, the nitrogen-alloyed EN 10088-2 1.4439 plate (4.0 – 5.0 % Mo) is the next step; where 2.50 – 3.00 % molybdenum is enough, 1.4435.

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.

1.4438 is weldable by the common arc and resistance processes.

• The Euro Inox fabrication tables rate TIG/MIG, manual metal arc and resistance welding as suitable for 1.4438, and autogenous welding as suitable with restrictions.
• Filler materials listed are 1.4440, 1.4438 and 1.4453.
• EN 10088-2 Table 7 rates 1.4438 “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 1.4438 forms with standard austenitic practice and work-hardens during forming, so forming forces are higher than for carbon steel and springback should be allowed for. Its minimum elongation is 35 – 40 %, slightly below that of the 316L grades.

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 1.4438 hot rolled plate and X2CrNiMo18-15-4 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.

1.4438 is listed in EN 10088-2 as cold rolled strip, continuously hot rolled strip and hot rolled plate, all solution annealed; as a special grade, not every size is rolled by every mill.

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 1.4438 hot rolled plate and 1.4438 cold rolled sheet, in standard sizes or cut to your drawing, after confirming availability with the mill.

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 give no polishability rating for 1.4438, so a polished finish should be agreed with the mill.

The usual 1.4438 equivalent, and the answer to most 317L equivalent enquiries, is UNS S31703.

For Chinese pressure vessels the grade is ordered as GB/T 713.7 S31703 pressure vessel plate with an agreed nickel minimum of 13.0 %. All three foreign grades allow nickel down to 11 %, below the 1.4438 minimum.

1.4438 vs 1.4435 and 1.4439

Compared with EN 10088-2 1.4435 plate, 1.4438 has 3.0 – 4.0 % molybdenum against 2.50 – 3.00 %, slightly more chromium and nickel, and the same plate proof strength in Table 7; its plate tensile range is 520 – 720 MPa with 40 % elongation. Compared with 1.4439, it has less molybdenum and no nitrogen addition, so its plate proof strength is lower (220 against 270 MPa).

Typical applications of 1.4438 plate and sheet listed in the Euro Inox fabrication tables include:

• Containers in the cellulose industry
• Process equipment in the cellulose industry
• Containers and process equipment in the textile industry
• Chemical equipment where 316L is not resistant enough
• Pressure parts (to EN 10028-7)

For pressure equipment, 1.4438 plate is ordered to EN 10028-7; for other uses, EN 10088-2 applies.

Buyers choose 1.4438 when 316L-type steels pit or crevice-corrode in service. SHH STEEL can advise when 1.4439 or a duplex grade is the better choice.

For 1.4438 the main risks are molybdenum or nickel below the EN minimums, certificates that only show 317L limits, and availability of a special grade.

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 1.4438 order is supported by documents and checks that make the material traceable to the heat:

• Cast analysis with molybdenum, nickel, chromium 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 cellulose, textile and chemical process 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 × 1 500 mm × 6 000 mm, EN ISO 18286, EN 10088-2, steel X2CrNiMo18-15-4 (1.4438), 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 1.4438 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 1.4438 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 X2CrNiMo18-15-4 1.4438 is the 317L-type austenitic special grade with 3.0 – 4.0 % molybdenum, supplied as hot rolled plate up to 75 mm and cold rolled sheet for cellulose, textile and chemical process 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.