X8Cr28 is a high-chromium ferritic heat-resistant stainless steel containing about 28% chromium. This datasheet presents the material within the EN symbol designation system.
With nominally 28% chromium and no deliberate nickel or molybdenum, X8Cr28 offers excellent resistance to oxidation, sulfidation and other forms of hot corrosion at elevated temperature. It is among the most oxidation-resistant of the ferritic stainless steels and is used in furnace and combustion equipment. Being a high-chromium ferritic, it is magnetic, cannot be hardened by heat treatment, and is largely immune to chloride stress-corrosion cracking, but it embrittles on exposure in the 425–540 °C range (475 °C embrittlement) and forms sigma phase on long exposure at intermediate temperatures. Its elevated-temperature strength is low.
Typical applications include furnace parts, kiln and annealing-box components, burner and combustion hardware, and equipment exposed to sulphur-bearing hot gases.
Typical values, annealed condition, per EN reference data.
| Property | Value | Unit |
|---|---|---|
| Density | 7.5 | g/cm³ |
| Melting range | 1425–1510 | °C |
| Elastic modulus | 220 | GPa |
| Coefficient of thermal expansion (20–100 °C) | 10.5 | µm/m·°C |
| Thermal conductivity (20 °C) | 21.0 | W/m·K |
| Specific heat (20 °C) | 500 | J/kg·K |
| Structure | Ferritic | — |
Specified per EN / DIN (W.Nr. 1.4763, X8Cr28).
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Iron | Fe | Balance | — | Base element |
| Chromium | Cr | 26.0 | 29.0 | Oxidation / hot-corrosion resistance |
| Manganese | Mn | — | 1.00 | Deoxidiser |
| Silicon | Si | — | 1.00 | Deoxidiser; oxidation resistance |
| Nickel | Ni | — | 0.50 | Residual |
| Carbon | C | — | 0.12 | Strength |
| Nitrogen | N | — | — | Residual |
| Phosphorus | P | — | 0.040 | Residual impurity |
| Sulphur | S | — | 0.015 | Residual impurity |
Nominal: 28Cr high-chromium ferritic heat-resistant stainless steel.
Annealed (+A) condition, per EN / DIN for W.Nr. 1.4763.
| Condition | Property | Value |
|---|---|---|
| Annealed | Tensile strength (Rm) | 450–650 MPa |
| Annealed | 0.2% proof strength (Rp0.2) | ≥270 MPa |
| Annealed | Elongation (A5) | ≥18 % |
| Annealed | Hardness | ≤200 HB |
| — | Elastic modulus | 220 GPa |
Values per EN / DIN; elevated-temperature strength is low — the alloy is selected for oxidation / hot-corrosion resistance. Confirm against the inspection certificate (EN 10204).
| Environment | Performance | Notes |
|---|---|---|
| High-temperature oxidation | Excellent | Among the best of the ferritics |
| Sulfidation / hot corrosion | Excellent | High chromium resists sulphur-bearing atmospheres |
| Chloride stress-corrosion cracking | Very Good | Ferritic — largely immune |
| 425–540 °C exposure | Poor (embrittlement) | 475 °C embrittlement — avoid this range |
| Sigma phase | Risk on long exposure | Around 540–700 °C |
The very high chromium content gives outstanding resistance to oxidation, sulfidation and hot corrosion; the alloy embrittles in the 425–540 °C range and forms sigma phase on long intermediate-temperature exposure.
A ferritic grade; cannot be hardened by heat treatment. Properties are set by annealing.
Anneal Heat to approximately 780–850 °C and cool in air (rapid cooling through 540–425 °C is preferred to limit embrittlement). Do not use in the 425–540 °C range in service unless loss of room-temperature ductility is acceptable.
Weldable with care; weld and heat-affected zone suffer grain growth and embrittlement. Use low heat input and an austenitic or nickel-base filler for ductility.
| Welding Process | Applicability | Filler / Consumable |
|---|---|---|
| GTAW / TIG | Acceptable | Austenitic or nickel-base for ductility |
| GMAW / MIG | Acceptable | Austenitic / nickel-base filler |
| SMAW / stick | Acceptable | Austenitic-type electrode |
Weld metal and HAZ have reduced toughness; austenitic or nickel-base fillers are preferred.
Machining Guidelines
| Parameter | Recommendation |
|---|---|
| Machinability | Fair; high chromium increases tool wear |
| Work hardening | Low rate |
| Coolant | Ample flood coolant |
Forming Processes
| Process | Notes |
|---|---|
| Cold forming | Limited — lower ductility than lower-Cr ferritics |
| Hot forming | ~1050–800 °C; anneal afterward; avoid slow cooling through embrittlement range |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Furnaces / heat treatment | Furnace parts, annealing boxes, muffles | Oxidation resistance at high temperature |
| Combustion | Burner nozzles, combustion chambers | Hot-corrosion / sulfidation resistance |
| Thermal processing | Kiln furniture, recuperators | High-temperature oxidation resistance |
| Metals processing | Hot-gas handling components | Sulfidation resistance |
| Product Form | DIN / EN Standard | Notes |
|---|---|---|
| Plate, sheet and strip | EN 10095 · W.Nr. 1.4763 | X8Cr28 |
| Bar, rod and sections | DIN 17440 · W.Nr. 1.4763 | — |
| Wire | W.Nr. 1.4763 | — |
| Technical delivery | SEW 470 | — |
High-chromium ferritic heat-resistant stainless steel. W.Nr. 1.4763 (X8Cr28).
| EN Symbol | Cr % | Mo % | C % | Best Used For |
|---|---|---|---|---|
| X8Cr28 | 26–29 | — | ≤0.12 | High-Cr heat-resistant ferritic; oxidation resistance |
| X6Cr17 | 16–18 | — | ≤0.08 | General ferritic; non-heat-resistant |
| X2CrMoTi18-2 | 17–20 | 1.8–2.5 | ≤0.025 | 18Cr-2Mo ferritic; corrosion resistance |
| X8CrNi25-21 | 24–26 | — | ≤0.10 | Austenitic heat-resistant (higher strength) |
| X15CrNiSi25-21 | 24–26 | — | ≤0.20 | Austenitic heat-resistant |




