EN 10088-2 X4CrNiMo16-5-1 1.4418 Stainless Steel Plate

EN 10088-2 X4CrNiMo16-5-1 1.4418 stainless steel plate is a soft martensitic flat product supplied to EN 10088-2, the European standard for stainless steel sheet, plate and strip for general purposes. X4CrNiMo16-5-1 contains no more than 0.06 % carbon, 15.0 – 17.0 % chromium, 4.0 – 6.0 % nickel, 0.80 – 1.50 % molybdenum and at least 0.020 % nitrogen. Compared with the 13 % chromium soft martensitic grade 1.4313, the higher chromium and molybdenum give better corrosion resistance at a similar strength level. EN 10088-2 lists 1.4418 only as hot rolled plate (product form P) up to 75 mm in the quenched and tempered condition +QT840. The grade is also one of the two martensitic grades in EN 10028-7 for pressure equipment.

SHH STEEL works as a steel sourcing partner with long-term relationships with Chinese stainless mills that roll quenched and tempered soft martensitic 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 1.4418 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 X4CrNiMo16-5-1 sheet and plate from China, and how SHH STEEL deals with each of them.

1.4418 plate can be ordered to EN 10088-2 for general purposes or to EN 10028-7 for pressure equipment; see EN 10028-7 1.4418 pressure vessel plate. There is no matching grade in ASTM A240. The nearest American soft martensitic plate grade is ASTM A240 S41500 sheet and plate (13Cr-4Ni), which has less chromium.

Neither American grade matches: S41500 has less chromium and molybdenum, and 431 has much more carbon and less nickel. Where a design calls for 1.4418, SHH STEEL supplies 1.4418 or states the differences clearly in the quotation.

1.4418 is one of only two martensitic grades in EN 10028-7:2016, the other being 1.4313; see EN 10028-7 1.4313 pressure vessel plate. EN 10028-7 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 1.4418 chemical composition below is the cast (heat) analysis from EN 10088-2:2014 Table 4. Values are percentages by mass; a single figure is a maximum.

* Footnote b of Table 4 permits controlled sulphur ranges for machinability (0.015 – 0.030 %), weldability (0.008 – 0.015 %) or polishability (0.015 % max.). The low carbon content and the balance of chromium and nickel give the tough soft martensitic structure. SHH STEEL checks chromium, nickel, molybdenum and nitrogen on every certificate as part of the 1.4418 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 1.4418 mechanical properties below are the room-temperature values from EN 10088-2:2014 Table 10 for martensitic steels in the heat-treated condition. The values depend on the heat-treatment condition as well as on the product form.

Table 10 gives a minimum impact energy of 55 J for plate thicker than 10 mm. For bigger sizes the mechanical values are to be agreed at the time of enquiry and order.

EN 10028-7 may set different or additional requirements for pressure equipment, so check that standard where it applies. SHH STEEL can arrange tensile and impact tests, witnessed by a third-party inspector when required.

Minimum 0.2 % proof strength at elevated temperature (EN 10088-2 Table 15, +QT840)

EN 10088-2 gives no values above 300 °C for 1.4418.

EN 10088-2 Table A.4 gives the following guideline temperatures for 1.4418:

The quenching range for 1.4418, 900 – 1 000 °C, is slightly lower than for 1.4313 (950 – 1 050 °C), and the tempering range is 570 – 650 °C. The Euro Inox fabrication tables give the same ranges.

EN 10088-2 lists no annealed condition for 1.4418 plate. The Annex A temperatures are guidelines; actual settings are chosen by the mill, and we check that the delivery condition is stated on each certificate.

The values below are approximate reference figures for X4CrNiMo16-5-1 at room temperature, as listed in EN 10088-1 and reproduced in stockholder datasheets. They are suitable for design estimates and weight calculation; where a figure is critical, use EN 10088-1 itself.

The thermal conductivity of 1.4418 (15 W/(m·K)) is about half that of the 13 % chromium hardening grades such as 1.4006 (30 W/(m·K)) and close to that of austenitic steels. The steel is magnetic.

1.4418 has better corrosion resistance than 1.4313, owing to its higher chromium and molybdenum. The ISSF guide on stainless steels in hydro turbines names 1.4313 and 1.4418 as the most suitable grades where cavitation erosion resistance is needed, and states that 1.4418 has similar properties to 1.4313 but better corrosion resistance. The Euro Inox fabrication tables describe it as resistant to water and dilute acids, heat treatable and of high strength. EN 10088-2 gives no corrosion data.

Where a lower-cost grade is acceptable, EN 10088-2 1.4313 plate gives similar strength with lower corrosion resistance.

Corrosion behaviour depends on medium, temperature and surface finish, so it should be confirmed for each application.

1.4418 can be welded with a controlled procedure; its low carbon content makes it far more weldable than the higher-carbon martensitic grades.

• The Euro Inox fabrication tables rate GTAW/MIG, MMA, resistance and autogenous welding as suitable for 1.4418, list an approximate preheating temperature of 350 °C, and give filler materials 1.4430 or 1.4462; the qualified procedure governs the actual values.
• Use low-hydrogen processes and dry consumables.
• Temper after welding to restore toughness, at the temperature set by the procedure.
• EN 10088-2 does not specify welding procedures; these are published guidelines and general practice.

These points reflect industry practice for soft martensitic (16 % Cr – 5 % Ni – Mo) 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.

1.4418 plate is delivered quenched and tempered and is normally cut, machined and welded in that condition. Its strength is high for a stainless steel, so bending is limited to generous radii and should be trialled first.

Thermal cutting is common for this low-carbon grade; preheating thick plate before plasma cutting reduces the risk of edge cracks. Machining needs rigid set-ups because of the high strength.

We run our own workshop next to the warehouse, so 1.4418 martensitic plate can be delivered as cut pieces, sawn blocks, rings or drilled parts instead of raw mill sizes. Details are on our steel cutting services and bending and forming services pages.

EN 10088-2 lists 1.4418 only as hot rolled plate.

Plate thicker than 75 mm is outside the range of Table 10, so its properties must be agreed. State the impact test temperature and any ultrasonic testing requirement in the order.

SHH STEEL can supply 1.4418 soft martensitic plate and X4CrNiMo16-5-1 plate in standard sizes or cut to your drawing, including blanks and rings for runners, impellers and valve bodies.

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.

Most 1.4418 plate is machined, so 1C or 1E is often the economical choice. Wetted surfaces are usually ground or polished after machining.

There is no 1.4418 equivalent in ASTM A240, in GB/T 20878-2024 or in the JIS flat-product standards. The grades sometimes offered instead differ significantly.

Because no foreign standard grade matches, 1.4418 is normally bought to EN 10088-2 or EN 10028-7 by name and number. SHH STEEL quotes the EN grade and does not offer a cross-referenced grade without the buyer’s written approval.

1.4418 vs 1.4313 and 431

Compared with EN 10088-2 1.4313 plate, 1.4418 has about 3 % more chromium, more nickel and more molybdenum, and higher minimum strength in EN 10088-2 (+QT840: Rp0.2 660 MPa, against 630 MPa for 1.4313 +QT780), with better corrosion resistance. Compared with 431, it has much less carbon and more nickel, so it is tougher and more weldable. Compared with EN 10088-2 1.4021 plate and EN 10088-2 1.4006 plate, it is a high-strength structural grade rather than a 13 % chromium hardening grade.

Typical applications of 1.4418 plate listed in published sources (ISSF and Euro Inox) include:

• Hydro turbine runners and guide vanes
• Components for pumps and centrifuges
• Mechanical engineering parts and arbors
• Valve components
• Parts exposed to water and dilute acids
• Pressure equipment parts made to EN 10028-7

For pressure equipment, 1.4418 plate is ordered to EN 10028-7; for other uses, EN 10088-2 applies. 1.4418 martensitic sheet is not listed in EN 10088-2, which covers only plate for this grade.

1.4418 QT840 is the only EN 10088-2 delivery condition, so strength and impact requirements beyond Table 10 must be agreed in the order. SHH STEEL can advise on the specification.

For 1.4418 the main risks are substitution by grades that are not equivalent, the wrong standard and incomplete impact testing.

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 1.4418 order is supported by documents and checks that make the material traceable to the heat:

• Cast analysis with chromium, nickel, molybdenum and nitrogen checked
• Tensile test for +QT840
• Impact test (KV2) as specified in Table 10 or agreed
• Ultrasonic testing of thick plate when agreed
• 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 turbine, pump and valve 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 t hot rolled plate, 40 mm × 2 000 mm × 4 000 mm, EN 10088-2, steel X4CrNiMo16-5-1 (1.4418), heat-treatment condition +QT840, process route 1D, inspection certificate 3.2 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; quenched and tempered plate includes the heat-treatment stage at the mill. 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 1.4418 and related martensitic and 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 1.4418 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 X4CrNiMo16-5-1 1.4418 is the 16 % chromium, 5 % nickel, 1 % molybdenum soft martensitic steel, supplied as +QT840 plate up to 75 mm for hydro turbines, pumps and valves where 1.4313 is not corrosion resistant enough. 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.