EN 10088-2 X6CrNiMoNb17-12-2 1.4580 Stainless Steel Plate

EN 10088-2 X6CrNiMoNb17-12-2 1.4580 stainless steel plate is a niobium-stabilised austenitic flat product supplied to EN 10088-2, the European standard for stainless steel sheet, plate and strip for general purposes. X6CrNiMoNb17-12-2 contains up to 0.08 % carbon, 16.5 – 18.5 % chromium, 10.5 – 13.5 % nickel, 2.00 – 2.50 % molybdenum and niobium from 10 × C up to 1.00 %. It is the niobium-stabilised counterpart of the titanium-stabilised 1.4571, with the same base analysis. EN 10088-2 places 1.4580 among its special grades, defined as grades for special use and/or with limited availability, and Table 7 lists it as hot rolled plate (P) up to 75 mm only, solution annealed. Strip and cold rolled sheet are therefore outside the standard offer. 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. 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 1.4580 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 X6CrNiMoNb17-12-2 sheet and plate from China, and how SHH STEEL deals with each of them.

1.4580 is the EN counterpart of UNS S31640, Type 316Cb, in ASTM A240. For pressure equipment it is ordered to EN 10028-7; see EN 10028-7 1.4580 pressure vessel plate.

A heat can meet both 1.4580 and S31640 with chromium of 16.5 – 18.0 %, molybdenum at most 2.50 %, niobium at most 1.00 % and silicon at most 0.75 %. ASTM also limits nitrogen to 0.10 %, while EN 10088-2 sets no nitrogen limit for 1.4580. SHH STEEL checks these overlaps when a buyer needs dual certification.

1.4580 is also listed in EN 10028-7:2016 for pressure purposes, as is the titanium-stabilised 1.4571 (EN 10028-7 1.4571 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 1.4580 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 1.4580 niobium content of at least ten times the carbon is what stabilises the steel; EN 10088-2 sets no nitrogen limit for this grade. SHH STEEL checks carbon, niobium and molybdenum on every certificate as part of the 1.4580 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 1.4580 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 bigger sizes than those listed, mechanical values are to be agreed at the time of enquiry and order.

EN 10088-2 lists 1.4580 as hot rolled plate only. A footnote to the entry states that for stretcher levelled material the minimum value is 5 % lower. Table 7 rates 1.4580 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 1.4580, so the grade is ordered in the solution annealed condition (+AT). Where a higher strength is needed, 1.4571 (+C700 and +C850) 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 1.4580:

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 1 030 – 1 110 °C range with cooling in air or water. Plate is delivered solution annealed (+AT); we check the condition on each certificate.

The values below are approximate reference figures for X6CrNiMoNb17-12-2 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 1.4580 the same values as 1.4571: 8.0 g/cm³, a modulus of 200 GPa and a thermal expansion of 17.5 × 10⁻⁶ /K from 20 to 200 °C. 1.4580 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 1.4580 for the chemical industry, especially resin, paint and rubber production, and describe it as similar to 1.4571. 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, which comes from niobium stabilisation rather than a low carbon limit. Its chromium and molybdenum ranges are the same as those of 1.4401 and 1.4571.

The titanium-stabilised alternative, listed among the standard grades, is EN 10088-2 1.4571 plate; the CrNi counterpart without molybdenum is EN 10088-2 1.4550 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.

1.4580 niobium stabilised plate is readily weldable by the common arc and resistance processes, and niobium stabilisation keeps the heat-affected zone resistant to intergranular corrosion.

• The Euro Inox fabrication tables rate TIG/MIG, manual metal arc and resistance welding as suitable for 1.4580, and autogenous welding as suitable with restrictions.
• Filler materials listed are 1.4430 and 1.4576; 1.4576 is a niobium-stabilised molybdenum filler.
• EN 10088-2 Table 7 rates 1.4580 “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, plate blanks are cut with clean, burr-free edges, ready for the fabricator’s own joint preparation.

Annealed 1.4580 plate 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.

Plate is cut by plasma or waterjet, or sawn. Machining needs sharp tools and positive feeds to avoid work hardening at the cut.

We run our own workshop next to the warehouse, so 1.4580 hot rolled plate and X6CrNiMoNb17-12-2 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 7 lists 1.4580 only as hot rolled plate (P) up to 75 mm. A footnote to the 1.4580 entry states that for stretcher levelled material the minimum value is 5 % lower.

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.

SHH STEEL can supply 1.4580 hot rolled plate 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.

EN 10088-2 Table 7 lists this grade 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 Euro Inox tables give no polishability rating for 1.4580.

The usual 1.4580 equivalent is UNS S31640, Type 316Cb, in ASTM A240.

The niobium maximum of the foreign grades (1.10 %) is above the 1.4580 limit of 1.00 %, and their molybdenum allows up to 3.00 %. For a titanium-stabilised alternative with wider availability, see EN 10088-2 1.4571 plate.

1.4580 vs 1.4571 and 1.4404

Compared with 1.4571, 1.4580 is stabilised with niobium (10 × C to 1.00 %) instead of titanium (5 × C to 0.70 %); the base analysis is the same, and Table 12 gives almost identical values. Its plate tensile range in Table 7 is 520 – 720 MPa against 520 – 670 MPa. Compared with EN 10088-2 1.4404 plate, it reaches intergranular corrosion resistance by stabilisation and has higher elevated-temperature proof strength (145 against 118 MPa Rp0.2 at 300 °C).

Typical applications of 1.4580 plate listed in the Euro Inox fabrication tables include:

• Chemical industry equipment
• Resin production plant
• Paint production plant
• Rubber production plant
• Pressure parts (to EN 10028-7)

For pressure equipment, 1.4580 plate is ordered to EN 10028-7; for other uses, EN 10088-2 applies.

Buyers choose 1.4580 when a specification names it or prefers niobium to titanium stabilisation. SHH STEEL can advise when 1.4571 would serve.

For 1.4580 the main risks are low niobium, 1.4571 supplied instead, and the plate-only listing in EN 10088-2.

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 1.4580 order is supported by documents and checks that make the material traceable to the heat:

• Cast analysis with carbon, niobium, chromium, nickel and molybdenum 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 chemical, resin, paint and rubber plant 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: 5 plates, 12 mm × 1 500 mm × 6 000 mm, EN ISO 18286, EN 10088-2, steel X6CrNiMoNb17-12-2 (1.4580), 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 1.4580 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 1.4580 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 1.4580 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 X6CrNiMoNb17-12-2 1.4580 is the niobium-stabilised 316Cb-type austenitic special grade, supplied as hot rolled plate up to 75 mm for welded chemical, resin, paint and rubber 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.