EN 10088-2 X2CrTiNb18 1.4509 Cold Rolled Stainless Steel Strip

EN 10088-2 X2CrTiNb18 1.4509 cold rolled stainless steel strip is a ferritic flat product supplied to EN 10088-2, the European standard for stainless steel sheet, plate and strip for general purposes. X2CrTiNb18 is one of the special grades of the standard: a low-carbon steel, maximum 0.030 %, with a tight 17.5 – 18.5 % chromium range and two stabilising elements, 0.10 – 0.60 % titanium and niobium of at least 3 × C + 0.30 %. The niobium in solution raises strength at high temperature and resistance to thermal fatigue, which is why 1.4509 is widely used in the hot parts of exhaust systems, while the higher chromium gives better general corrosion resistance than 430. EN 10088-2 covers it as cold rolled strip and sheet up to 8 mm.

SHH STEEL works as a steel sourcing partner with long-term relationships with Chinese stainless mills that roll dual-stabilised 18 % chromium ferritic grades for exhaust and appliance work. 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 1.4509 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 X2CrTiNb18 sheet and plate from China, and how SHH STEEL deals with each of them.

1.4509 can be ordered to EN 10088-2 for general use or to EN 10028-7 1.4509 pressure vessel plate for pressure equipment. In America the closest listing is UNS S43940 in ASTM A240, whose chromium, titanium and niobium limits are practically the same as those of 1.4509. The market name 441 is used for both S43940 and UNS S44100, and A240 gives neither a type name. Our ASTM A240 Type 441 sheet and plate page is written to S44100, which allows 17.5 – 19.5 % chromium and needs niobium of 9 × C + 0.30 % to 0.90 %, so a drawing that just says 441 should state the UNS number.

Automotive exhaust drawings often name 1.4509 or 441 interchangeably. Before the order, SHH STEEL checks whether the heat meets both sets of limits, so dual certification can be offered where the customer needs it.

Hot-end exhaust parts are often designed against heat-resisting behaviour such as oxidation and thermal fatigue, which EN 10088-2 does not specify. Where such data are needed, they should be taken from the mill or the designer’s own tests, and SHH STEEL can request available mill data with the quotation.

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 1.4509 chemical composition below is the cast (heat) analysis from EN 10088-2:2014 Table 3. Values are percentages by mass; a single figure is a maximum.

No separate nitrogen limit is given for 1.4509 in Table 3. The niobium minimum depends on the carbon of the heat: with 0.015 % carbon it is 3 × 0.015 + 0.30 = 0.345 % Nb, and at the carbon maximum it is 0.39 %. The chromium range of only 1 % is narrower than for most ferritics, so SHH STEEL checks chromium, niobium and titanium on every certificate as part of the 1.4509 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. How a tolerance applies to the calculated titanium minimum should be confirmed in the contract if a product analysis is ordered.

The 1.4509 mechanical properties below are the room-temperature values for the annealed condition in EN 10088-2:2014 Table 9. Only the cold rolled product form is listed for this special grade.

Elongation is measured on an 80 mm gauge length below 3 mm thickness and on a proportional gauge length (5.65√S0) from 3 mm upwards. For bigger sizes the values are to be agreed at the time of enquiry and order. Table 9 records resistance to intergranular corrosion (tested to EN ISO 3651-2) as “yes” in both the delivery and the welded condition.

The minimum elongation of 18 % is lower than for EN 10088-2 1.4510 plate (23 %), reflecting the niobium in solution, so forming limits should be checked for deep or complex parts. SHH STEEL can add hardness or extra tensile tests on request.

Minimum 0.2 % proof strength at elevated temperature (EN 10088-2 Table 14, +A)

No value is given at 400 °C in EN 10088-2. The higher-temperature strength that makes 1.4509 attractive for manifolds lies outside the range of this table, so design values above 350 °C must come from other sources, such as mill data.

X2CrTiNb18 plate and sheet are delivered in the annealed condition (+A). EN 10088-2 Table A.3 gives the guideline temperatures:

Annealing at 870 – 930 °C, followed by air or water cooling, is a higher range than for 1.4526 or 1.4513. It is needed to recrystallise the niobium-bearing structure and keep niobium in the condition that gives good high-temperature strength.

As with all 17 % chromium and higher ferritics, long exposure around 400 – 550 °C can cause 475 °C embrittlement, prolonged exposure at higher temperatures can form sigma phase, and over-heating coarsens the grain. These effects are general knowledge for the grade family rather than EN 10088-2 requirements. The Annex A temperatures are guidelines; actual furnace settings are chosen by the mill, and we check that the annealed condition is stated on each certificate.

In service at high temperature, niobium can precipitate as Laves phase over long periods, which can reduce room-temperature toughness of parts after use. This is a known feature of niobium-bearing ferritics and is managed in design rather than by EN 10088-2.

The values below are room-temperature reference figures for X2CrTiNb18 1.4509, taken from the physical-property table in Euro Inox, Stainless Steel: Tables of Technical Properties (Materials and Applications Series, Volume 5). They are suitable for design estimates and weight calculation; where a figure is critical, use EN 10088-1 itself.

Low thermal expansion is a key benefit for exhaust manifolds and catalytic converter shells: compared with austenitic grades, 1.4509 expands much less when heated, so thermal stresses and distortion in cyclic heating are lower.

With 17.5 – 18.5 % chromium, 1.4509 has better general and pitting corrosion resistance than 430 and 1.4512, and in many indoor and mild environments it is compared with 304. Dual stabilisation keeps welds resistant to intergranular corrosion. At high temperature, the chromium forms a protective oxide that gives good oxidation resistance for a ferritic of this chromium level.

For cold-end parts with heavy chloride exposure, molybdenum grades such as EN 10088-2 1.4513 plate or EN 10088-2 1.4521 plate are more suitable. The temperatures above are typical industry figures, not requirements of EN 10088-2, and depend on part design and gas composition.

1.4509 has good weldability for a ferritic stainless steel. Titanium deoxidises and stabilises, while niobium helps refine the weld zone and keeps strength at temperature. Thin sheet is welded by TIG, MIG, plasma, laser and resistance processes without preheat.

• Keep heat input low to limit grain growth in the heat-affected zone.
• For exhaust tubes, use a niobium-bearing ferritic filler (for example an 18 % Cr Nb type) so that the weld keeps high-temperature strength; an austenitic filler can differ in thermal expansion.
• Shield the root with argon on tube welds to avoid oxidation.
• Remove heat tint on visible appliance parts.
• Post-weld annealing is not normally needed.

These points reflect industry practice for dual-stabilised 18 % chromium ferritics 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.

In the annealed condition 1.4509 ferritic sheet bends and forms well enough for tube bending, hydroforming and pressing of manifold shells, but its elongation of 18 % minimum is lower than that of 1.4510 or 1.4520, so very deep draws need care. Springback is typical of ferritics.

Machining is comparable to other stabilised ferritic grades and easier than for austenitic steels; the hard titanium or niobium carbonitrides that stabilise the steel can wear tools a little faster, so sharp tools and steady feeds are recommended. Punching and drilling of thin sheet is routine.

We run our own workshop next to the warehouse, so 1.4509 can be delivered as slit coil, cut-to-length sheets, laser-cut blanks or bent parts instead of raw mill sizes. Details are on our steel cutting services and bending and forming services pages. Protective film can be applied for visible or deep-drawn parts.

Because EN 10088-2 lists 1.4509 only as cold rolled strip and sheet, the supply range is thin gauge.

Exhaust tube mills usually need slit strip with narrow width tolerance, low camber and clean edges, so state these together with the EN ISO 9445 thickness class.

SHH STEEL can supply 1.4509 cold rolled sheet in standard sizes or cut to your drawing, slit coil for tube mills, and laser-cut flanges and heat-shield blanks. Hot rolled plate in this grade is not covered by EN 10088-2.

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.

For exhaust parts the surface finish is mostly a matter of cleanliness and freedom from defects, while appliance parts need BA or brushed finishes and protection. State the end use in the enquiry, and SHH STEEL can apply PVC film where needed.

Buyers looking for a 441 stainless steel equivalent in European terms will be offered 1.4509. The American and Chinese grades are close, while Japan has no listed equivalent.

As a 1.4509 equivalent, UNS S43940 is the practical match, and most heats can be certified to both, since the chromium, titanium and niobium limits coincide. Note that 441 is a market name rather than an A240 type designation, and that it is also used for UNS S44100, which requires niobium of at least 9 × C + 0.30 %; confirm which UNS number the customer means. UNS S43932, a titanium plus niobium stabilised 17.0 – 19.0 % chromium grade of the 439 family, is sometimes cross-referenced as well, but its stabilisation rule differs and it is not a 1.4509 match.

1.4509 vs 1.4510, 1.4512 and 1.4526

Compared with EN 10088-2 1.4510 plate, the counterpart of ASTM A240 Type 439 sheet and plate, 1.4509 adds niobium for high-temperature strength and thermal fatigue resistance, which is why it is preferred at the hot end of exhaust systems. Compared with 1.4512 (409 type), it has much more chromium, giving better oxidation and corrosion resistance. Compared with EN 10088-2 1.4526 plate, it has no molybdenum but more chromium and better hot strength, so the choice depends on whether the part is at the hot end or exposed to road salt.

Typical applications of 1.4509 ferritic plate and sheet include:

• Exhaust manifolds, front pipes and catalytic converter shells
• Diesel particulate filter housings and heat shields
• Cooker and oven parts, burners and hob components
• Heat exchangers and boiler parts in domestic heating
• Catering equipment and appliance interiors
• Indoor architectural parts where a nickel-free alternative to 304 is wanted

Where the part carries pressure, the order should use EN 10028-7. For very high temperatures, beyond the typical range of 1.4509, heat-resisting grades to EN 10095 are usually considered, and SHH STEEL can advise on the alternatives.

Because 1.4509 serves both the exhaust and the appliance market, the same chemistry may be supplied with very different surface and flatness requirements; make sure the enquiry says which one applies.

Most problems with 1.4509 come from substitution with titanium-only grades and from strip quality for tube mills.

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 1.4509 order is supported by documents and checks that make the material traceable to the heat:

• Cast analysis with chromium, niobium minimum and titanium range checked
• Tensile test on the annealed sheet: Rp0.2, Rm and A
• Intergranular corrosion test to EN ISO 3651-2 when ordered
• Dimensional and edge inspection of slit strip against EN ISO 9445
• 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 automotive 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: 12 t cold rolled strip, 1.5 mm × 205 mm slit coil, EN 10088-2, steel X2CrTiNb18 (1.4509), process route 2B, 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; slit coil for tube mills is processed in our workshop after the mill coil arrives. 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 1.4509 and related ferritic 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 1.4509 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 X2CrTiNb18 1.4509 is the dual-stabilised 18 % chromium ferritic of the 441 type, chosen for hot-end exhaust parts, cookers and appliances where heat and corrosion resistance must come without nickel. 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.