1.4571 steel (1.4571): properties, composition, equivalents
1.4571 (X6CrNiMoTi17-12-2, 316Ti) is the Ti-stabilized 316 of EN 10088: 2–2.5 % Mo, Ti ≥ 5×C. 220–240 MPa yield, 520–690 MPa tensile, PREN ≈ 24, creep-resistant to 550 °C. Data and 316Ti/SUS316Ti equivalents.
What is 1.4571?
1.4571 (X6CrNiMoTi17-12-2) is the titanium-stabilized member of the 316 family and, with 1.4404, one of the two grades German engineers mean by "V4A". Instead of driving carbon down to 0.03 %, the mill adds titanium at five times the carbon content; the carbon precipitates as harmless TiC during hot rolling, so the 17 % Cr / 2.2 % Mo matrix keeps its full corrosion resistance after welding or after service at 400–550 °C.
That heat stability is the reason 1.4571 remains the specified grade in German, Austrian and Eastern-European pressure-vessel, exhaust, flue-gas and chemical plant drawings (EN 10028-7, AD 2000). Strength is 10–20 MPa above 1.4404, creep strength is markedly better, and PREN is the same ≈ 24.
The price is surface quality: titanium carbonitride stringers show as fine streaks after bright polishing and can nucleate pits in thin sheet, so hygienic and decorative applications moved to 1.4404. Outside Europe, 316Ti is rare — ASTM lists it as S31635 but US mills stock 316L — and the cross-reference table explains what to accept as a substitute.
1.4571 chemical composition
| Element | Mass % | Note |
|---|---|---|
| C | ≤ 0.08 | |
| Si | ≤ 1 | |
| Mn | ≤ 2 | |
| P | ≤ 0.045 | |
| S | ≤ 0.015 | |
| Cr | 16.5 – 18.5 | |
| Mo | 2 – 2.5 | |
| Ni | 10.5 – 13.5 | |
| Ti | 5 × C – 0.7 | stabilizing ratio Ti ≥ 5×C, max 0.70 % |
EN 10088-2:2014 Table 3. Titanium ties up carbon as TiC so the steel cannot sensitize at 500–800 °C — the alternative to lowering carbon (1.4404).
1.4571 mechanical properties
| Thickness / condition | Yield strength ReH / Rp0.2 MPa (ksi) | Tensile strength Rm MPa (ksi) | Elongation A % | Hardness |
|---|---|---|---|---|
| Cold-rolled sheet (C), ≤ 8 mm, +AT | ≥ 240 (≥ 34.8) | 540–690 (78.3–100.1) | 40 | ≤ 215 HB |
| Hot-rolled strip (H), ≤ 13.5 mm, +AT | ≥ 220 (≥ 31.9) | 520–670 (75.4–97.2) | 40 | ≤ 215 HB |
| Hot-rolled plate (P), ≤ 75 mm, +AT | ≥ 220 (≥ 31.9) | 520–670 (75.4–97.2) | 40 | ≤ 215 HB |
| Bar ≤ 160 mm, +AT (EN 10088-3) | ≥ 200 (≥ 29.0) | 500–700 (72.5–101.5) | 40 | ≤ 215 HB |
| Rp0.2 at 300 °C (EN 10028-7) | ≥ 145 (≥ 21.0) | — | — | — |
| Rp0.2 at 500 °C (EN 10028-7) | ≥ 125 (≥ 18.1) | — | — | — |
Solution annealed 1020–1120 °C. Elevated-temperature minimums per EN 10028-7 (pressure-vessel plate).
Impact toughness
1.4571 requires a minimum Charpy V-notch energy of 60 J at -196 °C (typical). Austenitic; suitable for cryogenic service.
1.4571 equivalent grades
| Grade | System | Match | Why / differences |
|---|---|---|---|
| 316Ti | AISI / SAE | Identical | UNS S31635 (ASTM A240 316Ti): C ≤ 0.08, Cr 16–18, Ni 10–14, Mo 2–3, Ti 5×(C+N)–0.70. Rarely stocked in the USA. |
| 320S31 | BS (superseded British) | Identical | BS 1449 320S31. |
| 06Cr17Ni12Mo2Ti | GB/T (China) | Identical | GB/T 20878 06Cr17Ni12Mo2Ti (formerly 0Cr18Ni12Mo2Ti). |
| 10Kh17N13M2T | GOST (Russia/CIS) | Identical | GOST 5632 10Kh17N13M2T: C ≤ 0.10, Cr 16–18, Ni 12–14, Mo 2–3, Ti 5×C–0.7 — the Russian workhorse Mo grade. |
| SUS316Ti | JIS (Japan) | Identical | JIS G4304 SUS316Ti: C ≤ 0.08, Cr 16–18, Ni 10–14, Mo 2–3, Ti ≥ 5×C. |
| 316L | AISI / SAE | Near | Same corrosion class; 316L achieves weld-zone stability by low carbon instead of Ti. Usual substitute outside Europe. |
| 316 | AISI / SAE | Near | 316Ti — Ti-stabilized; equivalent corrosion class, better at 400–550 °C. |
| 1.4404 | EN (European) | Near | Low-carbon route to the same stability; better polish, slightly lower strength. |
| 1.4401 | EN (European) | Near | Unstabilized 316; sensitizes in thick welds. |
Identical = same composition and mechanical limits within rounding. Near = one limit differs (e.g. carbon max or impact temperature). Functional = interchangeable for most uses after an engineering check. Full cross-reference for 1.4571 →
Old and superseded designations
| Old name | Standard | Note |
|---|---|---|
| X10CrNiMoTi18 10 | DIN 17440 (withdrawn) | Same number 1.4571; name changed in EN 10088. |
| 320S31 | BS 1449 | British 316Ti. |
| Z6CNDT17-12 | NF A 35-573 |
Product forms and tolerance standards
Product forms: hot-rolled plate (dominant form), cold-rolled sheet, bar, forgings, profiles, seamless and welded pipe (EN 10216-5 / 10217-7), fittings and flanges.
Dimensional tolerances: plate: EN 10029; cold-rolled: EN ISO 9445-2; bar: EN 10278 / EN 10060.
Key property values
1.4571 yield strength
Rp0.2 ≥ 220 MPa plate, ≥ 240 MPa cold-rolled (≈ 32–35 ksi); at 300 °C ≥ 145 MPa, at 500 °C ≥ 125 MPa (EN 10028-7).
1.4571 tensile strength
520–670 MPa plate, 540–690 MPa cold-rolled.
1.4571 hardness
Max 215 HB solution annealed; not hardenable by heat treatment.
Corrosion and heat resistance
PREN ≈ 24; intergranular corrosion resistant in the as-welded and 500–800 °C-exposed condition (EN ISO 3651-2 passes without sensitization). Maximum continuous service ≈ 550 °C for pressure parts; scaling resistance in air to ~850 °C.
Physical properties
Density 8.0 g/cm³, E = 200 GPa, expansion 16.5 × 10⁻⁶/K, conductivity 15 W/m·K, non-magnetic annealed.
Heat treatment
Solution anneal 1020–1120 °C, quench in water or air. Stabilizing anneal (870–900 °C) is possible for maximum intergranular resistance.
Weldability
Very good weldability; filler 19 12 3 Nb (ER318) or 19 12 3 L (ER316L). Titanium does not transfer across the arc, so unstabilized filler is acceptable when C ≤ 0.03 %. No preheat, interpass ≤ 150 °C, no PWHT required. Pickle welds for corrosive service.
Machining, forming and heat treatment
Machinability ≈ 40 %; TiC particles increase tool wear slightly relative to 1.4404. Forming and bending excellent; polishing to mirror finish is difficult (streaking). Preferred for heavy plate, forged flanges and machined pressure parts rather than decorative sheet.
Typical applications
- Pressure vessels, columns and heat exchangers to EN 10028-7 / AD 2000 (German-spec projects)
- Chemical and petrochemical piping and valves
- Exhaust systems, flue-gas ducting and scrubbers
- Textile, paper and pulp equipment
- Food industry heavy equipment (non-polished)
- Structural parts in warm marine and de-icing environments
1.4571 compared with related grades
Frequently asked questions
Is 1.4571 the same as 316L?
Not identical but equivalent in corrosion class. 1.4571 (316Ti) is titanium-stabilized with up to 0.08 % C; 316L is low-carbon (≤ 0.03 %). Both resist weld sensitization. 316L can generally replace 1.4571 for ambient service; for service above 400 °C, 1.4571 is superior.
What is the ASTM equivalent of 1.4571?
UNS S31635 / ASTM A240 Type 316Ti. Because it is seldom stocked in North America, specifications usually allow 316L (S31603) as an alternative.
Why does 1.4571 not polish well?
Titanium combines with carbon and nitrogen into hard TiC/TiN particles that appear as streaks and pin-holes on a bright-polished surface. For mirror or hygienic finishes use 1.4404.
What is 1.4571 used for?
Pressure equipment and piping in the chemical, petrochemical and power industries, exhaust and flue-gas systems, heat exchangers, and heavy plate structures in corrosive environments — especially in projects built to German standards (AD 2000, EN 13445 with EN 10028-7).
Related grades
Verified against EN 10088-2:2014; EN 10088-2:2014 Tables 3 and 12; EN 10028-7:2016; ASTM A240/A240M-22 (comparison). Last checked: September 2026.