1.4563 is a high-alloy, multi-purpose austenitic stainless steel (iron–nickel–chromium–molybdenum–copper) developed for service in highly corrosive conditions. This datasheet presents the material within the European (EN / DIN / Werkstoff-Nummer) standard system.
It is characterised by very high corrosion resistance in strong acids, very good resistance to stress-corrosion cracking (SCC) and intergranular corrosion across a range of environments, high resistance to pitting and crevice corrosion, and good weldability. The high chromium (27%) and nickel (31%) contents give excellent SCC resistance; molybdenum and copper provide outstanding resistance to sulphuric and phosphoric acids; and the low carbon content (≤0.020%) minimises sensitisation in welded joints.
Originally developed for the manufacture of phosphoric acid — where it is today the most widely used metallic material for evaporator tubes by the "wet" method — it is also used in sulphuric-acid plant, deep sour oil and gas wells, fluoride-bearing off-gas handling, nuclear-plant heat exchangers, and seawater/chloride-bearing cooling-water systems. It should not be exposed to temperatures above ~593 °C (1100 °F) for prolonged periods, to avoid embrittlement.
Values per manufacturer (Alleima / Sandvik) data, solution-annealed condition.
| Property | Value | Unit |
|---|---|---|
| Density | 8.0 | g/cm³ |
| Young's modulus (20 °C) | 195 | GPa |
| Specific heat capacity (20 °C) | 460 | J/kg·K |
| Thermal conductivity (20 °C) | 12 | W/m·K |
| Electrical resistivity (20 °C) | 1.0 | µΩ·m |
| Coefficient of thermal expansion (20–100 °C) | 15.8 | µm/m·°C |
| Maximum service temperature (continuous) | ~593 | °C |
| Structure | Austenitic (FCC) | — |
Composition per EN 10088-2 / EN 10272 (W.Nr. 1.4563, X1NiCrMoCu31-27-4).
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Nickel | Ni | 30.0 | 32.0 | Austenitic matrix; SCC resistance |
| Chromium | Cr | 26.0 | 28.0 | Passivity; pitting resistance |
| Iron | Fe | Balance | — | Base element |
| Molybdenum | Mo | 3.0 | 4.0 | Pitting + reducing-acid resistance |
| Copper | Cu | 0.7 | 1.5 | Sulphuric-acid resistance |
| Manganese | Mn | — | 2.0 | Deoxidiser |
| Silicon | Si | — | 0.7 | Deoxidiser |
| Nitrogen | N | — | 0.11 | Austenite stability |
| Carbon | C | — | 0.02 | Very low (intergranular resistance) |
| Phosphorus | P | — | 0.03 | Residual impurity |
| Sulphur | S | — | 0.01 | Residual impurity |
Nominal: Ni-31Cr-27Mo-3.5Cu. Per EN 10272 the grade is named X1NiCrMoCu31-27-4. Resistant to intergranular corrosion in the delivery and sensitized condition; not for service below -270 °C.
Annealed (+A) condition, per EN 10088-2 for W.Nr. 1.4563.
| Property | Value | Unit |
|---|---|---|
| Tensile strength (Rm) | 500–750 | MPa |
| 0.2% proof strength (Rp0.2) | ≥220 | MPa |
| Elongation at fracture (A) | 35–40 | % |
| Impact energy (KV, +20 °C, long.) | ≥100 | J |
| Impact energy (KV, -196 °C) | ≥60 | J |
| Brinell hardness | ≤230 | HB |
Values per EN; confirm against the inspection certificate (EN 10204).
| Environment | Performance | Notes |
|---|---|---|
| Phosphoric acid (wet-process) | Outstanding | The benchmark material for evaporator tubes; far more tolerant of Cl⁻/F⁻ impurities than other high-alloy grades |
| Sulphuric acid | Outstanding | Resistant 40–70% and >85%; comparable to Alloy C in 98% H₂SO₄ |
| Hydrochloric acid | Very Good | Better than lower Cr-Mo stainless steels |
| Hydrofluoric / hydrofluosilicic acid | Very Good | Suitable where these occur as impurities |
| Nitric acid | Excellent | <0.15 mm/y in boiling 65% HNO₃ (Huey-type test) |
| Formic / acetic acid | Excellent | More resistant than 316L, 317L and 904L |
| Chloride stress-corrosion cracking | Outstanding | 27% Cr + 31% Ni; resists SCC where 1.4301/1.4401 fail |
| Pitting and crevice corrosion | High | Higher CPT than 904L and 825 |
| Sodium hydroxide (caustic) | Very Good | Superior to 1.4301/1.4401; alternative to pure nickel |
| Sour service (H₂S + chlorides) | Excellent | ISO 15156-3 MR0103 / MR0175 listed |
Austenitic; NOT age-hardenable. Heat treatment is solution annealing only; strength is increased by cold work.
Solution Anneal Temperature: ~1080–1180 °C, followed by rapid cooling (water quench) Purpose: Dissolves precipitates, restores maximum corrosion resistance, recrystallises structure.
Service limit: Avoid prolonged exposure above ~593 °C (1100 °F) to prevent embrittlement. Solution annealing may be performed after welding to relieve residual stress where required.
Good weldability. TIG/GTAW is the first choice; MMA/SMAW and gas-shielded arc welding are also suitable. As a fully austenitic steel it has low thermal conductivity and high thermal expansion, so welding sequences should be planned to minimise distortion. Recommended heat input <1.0 kJ/mm and interpass temperature <150 °C, using a string-bead technique.
| Welding Process | Applicability | Filler / Consumable |
|---|---|---|
| GTAW / TIG | Excellent (first choice) | ISO 14343 S 27 31 4 Cu L |
| GMAW / MIG | Good | ISO 14343 S 27 31 4 Cu L |
| SMAW / stick | Good | ISO 3581 E 27 31 4 Cu L R |
Low carbon content makes the risk of intergranular attack after welding minimal. Solution anneal after welding if residual stress is a concern.
Machining Guidelines
| Parameter | Recommendation |
|---|---|
| Work hardening | Moderately high rate; intermediate anneals may be required |
| Tooling | Rigid setup, sharp tools (austenitic-stainless practice) |
| Coolant | Flood coolant recommended |
| Preferred condition | Solution-annealed |
Forming Processes
| Process | Notes |
|---|---|
| Hot forming | Followed by solution anneal for optimal corrosion resistance |
| Cold forming | Readily cold-formed; moderately high work-hardening rate; intermediate anneals for heavy reductions |
| Annealing | Recommended after hot or cold forming to restore SCC resistance |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Phosphoric acid production | Evaporator tubes, heat exchangers, piping | Resistance to Cl⁻/F⁻-contaminated wet-process acid |
| Sulphuric acid plant | Piping, heat exchangers | 40–70% and >85% H₂SO₄ resistance |
| Oil and gas | Sour-well production tubing, casing, liners, wirelines | SCC + sour-service resistance (ISO 15156-3) |
| Fertiliser / fluoride off-gas | Scrubbers, gas-recovery equipment | Fluoride-bearing off-gas resistance |
| Nuclear power | Heat exchangers | SCC, pitting, crevice resistance |
| Seawater / cooling water | Seawater piping, chloride-cooled heat exchangers | Pitting and crevice resistance |
| Product Form | EN / DIN Standard | Other |
|---|---|---|
| Seamless tube and pipe | EN 10216-5 | SEW 400, SS 14 25 84, NFA 49-217 |
| Plate, sheet and strip | EN 10088-2 | SS 14 25 84 |
| Bar | EN 10088-3 · EN 10272 | SS 14 25 84 |
| Composition / designation | EN Number 1.4563 · EN Name X1NiCrMoCuN31-27-4 | DIN, AFNOR Z1NCDU31-27-03 |
| Welding consumables | ISO 14343 S 27 31 4 Cu L · ISO 3581 E 27 31 4 Cu L R | — |
VdTÜV-Werkstoffblatt 483; ISO 15156-3 MR0103 and ISO 15156-3 / ISO 15156 listed.
| W.Nr. | Ni % | Cr % | Mo % | Other | Best Used For |
|---|---|---|---|---|---|
| 1.4563 | 31 | 27 | 3.5 | Cu 1.0 | Phosphoric/sulphuric acid; sour gas; SCC resistance |
| 1.4539 | 25 | 20 | 4.5 | Cu 1.5 | Sulphuric acid; lower-alloy economy grade |
| 2.4858 | 42 | 21.5 | 3 | Cu 2.3 | Phosphoric/sulphuric acid; higher Ni |
| 2.4660 | 34 | 20 | 2.5 | Cu 3.3 | Sulphuric acid; Nb-stabilised |
| 2.4819 | bal | 15.5 | 16 | W 4 | Severe reducing acids; far higher Mo |




