# X5NiCrAlTi31-20 (1.4958 / Alloy 800H) Forgings

**Manufacturer:** Jiangyin Jiangnan Metal Co., Ltd. — open-die forging factory
**Address:** No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
**Telephone / WhatsApp / WeChat:** +86-189-2135-9659
**Email:** sales@steelforgepieces.com
**Web:** https://www.steelforgepieces.com/Nickel-Alloy/X5NiCrAlTi31-20.html
**Updated:** 2 September 2026

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## Summary

X5NiCrAlTi31-20 is the EN chemical designation for the iron-nickel-chromium heat resistant alloy with material number 1.4958, the European equivalent of Alloy 800H (UNS N08810). It contains 30.0 to 32.5 percent nickel and 19.0 to 22.0 percent chromium with controlled aluminium and titanium. It is supplied solution annealed with a grain size of ASTM 5 or coarser for creep and stress rupture service above 593 °C.

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. The company forges X5NiCrAlTi31-20 into rings, seamless rolled rings, discs, tube sheets, shafts, flanges, sleeves, bushings and bars to customer drawing, supplied solution annealed with EN 10204 3.1 or 3.2 certification.

## Key facts

| Item | Value |
|---|---|
| Alloy type | Austenitic iron-nickel-chromium heat resistant alloy, solid solution strengthened |
| Nominal composition | Fe bal., Ni 30.0-32.5, Cr 19.0-22.0, Al 0.20-0.50, Ti 0.20-0.50 |
| Delivery condition | Solution annealed, grain size ASTM 5 or coarser |
| Minimum properties at 20 °C | Rm ≥ 450 MPa, Rp0.2 ≥ 170 MPa, A ≥ 30% |
| Density | 7.94 g/cm³ |
| Service range | Above 593 °C where creep and rupture strength govern |
| Forged forms | Rings, rolled rings, discs, tube sheets, shafts, flanges, sleeves, bushings, hollow bars, round bars |
| Certification | EN 10204 3.1 standard; 3.2 with third party inspection on request |
| Manufacturer | Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China |

## What X5NiCrAlTi31-20 is

X5NiCrAlTi31-20 is a wrought austenitic iron-nickel-chromium alloy listed in EN 10088-1 under material number 1.4958. The nominal composition is approximately 31 percent nickel and 21 percent chromium with the balance iron, together with controlled additions of aluminium and titanium.

The alloy is solid solution strengthened and is not precipitation hardened. Its creep and stress rupture strength depend on the carbon content and on the grain size. The material is solution annealed above 1100 °C to produce a grain size of ASTM 5 or coarser. A fine grained heat with the same chemical analysis will pass a room temperature tensile test but will not provide the creep properties for which the grade is specified. For that reason the annealing temperature and the grain size are recorded on the certificate for every X5NiCrAlTi31-20 order produced by Jiangyin Jiangnan Metal.

Resistance properties:

- **Oxidation.** Chromium and aluminium form a stable protective oxide scale in air at high temperature.
- **Carburisation and nitriding.** The high nickel content gives resistance in reformer and cracking furnace atmospheres.
- **Chloride stress corrosion cracking.** The nickel level places the alloy outside the range in which austenitic stainless steels are most susceptible.
- **Creep.** The coarse grain size and stable carbides provide rupture strength above the useful range of 304H and 316H.

## Designations and equivalents

| System | Designation | Standards |
|---|---|---|
| EN chemical | X5NiCrAlTi31-20 | EN 10088-1, EN 10095, EN 10302 |
| EN numeric | 1.4958 | Material number used on European drawings |
| UNS | N08810 | ASTM B408, B409, B564; ASME SB-408, SB-409, SB-564 |
| Trade name | Alloy 800H / Incoloy 800H | Incoloy is a trademark of Special Metals Corporation |
| ISO | FeNi32Cr21AlTi-HC | HC denotes the high carbon, creep resisting variant |
| VdTÜV | Wb 412 / Wb 434 | German pressure equipment material sheets |
| DIN, superseded | DIN 17459 / 17460 | Still quoted on older drawings |

## Chemical composition, mass percent

| Element | EN 10088-1 min | EN 10088-1 max | Melt aim range |
|---|---|---|---|
| Ni | 30.0 | 32.5 | 30.0-32.0 |
| Cr | 19.0 | 22.0 | 19.0-22.0 |
| Fe | balance | balance | balance |
| C | 0.03 | 0.08 | 0.06-0.08 |
| Mn | — | 1.50 | 0.50-1.00 |
| Si | — | 0.70 | 0.20-0.60 |
| Al | 0.20 | 0.50 | 0.20-0.40 |
| Ti | 0.20 | 0.50 | 0.20-0.50 |
| Al + Ti | — | — | ≤ 0.70 |
| Cu | — | 0.50 | ≤ 0.50 |
| Co | — | 0.50 | ≤ 0.50 |
| P | — | 0.015 | ≤ 0.015 |
| S | — | 0.010 | ≤ 0.010 |
| N | — | 0.030 | ≤ 0.030 |

Specification limits to EN 10088-1:2023. The melt aim range is internal works practice and is not a standard requirement.

### Carbon range for dual EN and ASTM certification

EN 10088-1 specifies 0.03 to 0.08 percent carbon for 1.4958. ASTM specifies 0.05 to 0.10 percent for UNS N08810. A heat therefore satisfies both specifications only if the carbon content falls between 0.05 and 0.08 percent. Where a drawing calls for dual certification to 1.4958 and N08810, state this on the enquiry so that carbon is controlled at the melting stage.

## Mechanical and physical properties

Minimum room temperature properties, solution annealed:

| Property | Symbol | Minimum |
|---|---|---|
| Tensile strength | Rm | 450 MPa (65 ksi) |
| 0.2 percent proof strength | Rp0.2 | 170 MPa (25 ksi) |
| Elongation | A | 30 percent |
| Grain size | ASTM E112 | ASTM 5 or coarser |

Typical physical properties, for design guidance:

| Property | Value |
|---|---|
| Density | 7.94 g/cm³ |
| Melting range | approx. 1357-1385 °C |
| Modulus of elasticity at 20 °C | approx. 196 GPa |
| Magnetic response, annealed | essentially non-magnetic |
| Structure | austenitic, face centred cubic |

ASTM B564 states that UNS N08800 is normally used at service temperatures up to and including 593 °C, and that UNS N08810 and N08811 are used above 593 °C where resistance to creep and rupture is required. This is the main reason for selecting X5NiCrAlTi31-20 in place of Alloy 800.

## Alloy 800, 800H and 800HT compared

| Property | Alloy 800 | Alloy 800H | Alloy 800HT |
|---|---|---|---|
| EN name | X10NiCrAlTi32-21 | X5NiCrAlTi31-20 | X8NiCrAlTi32-21 |
| Material number | 1.4876 | 1.4958 | 1.4959 |
| UNS | N08800 | N08810 | N08811 |
| Carbon, ASTM | ≤ 0.10 | 0.05-0.10 | 0.06-0.10 |
| Carbon, EN | — | 0.03-0.08 | 0.05-0.10 |
| Combined Al + Ti | not specified | not specified | 0.85-1.20 |
| Grain size | fine | ASTM 5 or coarser | ASTM 5 or coarser |
| Normal service | up to 593 °C | above 593 °C | above 593 °C |
| Selected for | corrosion, general heat | creep and rupture | highest rupture strength |

If the component operates above 593 °C, or if the drawing specifies a grain size, an annealing temperature above 1100 °C, or an ASME code case, the correct grade is X5NiCrAlTi31-20 / 1.4958. If a combined aluminium plus titanium content of 0.85 to 1.20 percent is required, the grade is 800HT / 1.4959.

## Forged shapes and size range

All items are forged to customer drawing. X5NiCrAlTi31-20 is not held in stock; forgings are produced against the order from an ingot sized for the part.

Seamless rolled rings; forged rings and retaining rings; discs, blanks and tube sheets; flanges (weld neck, slip-on, blind, orifice); shafts, stepped shafts and spindles; sleeves, bushings and hollow bars; round bars and forged billets; blocks, plates and rectangular forgings; valve bodies, seat rings and stems; nozzles, couplings and manifolds; gear blanks and pinion blanks; near-net-shape and rough machined parts.

| Form | Dimension range | Piece weight |
|---|---|---|
| Seamless rolled rings | OD 200-4000 mm, height 40-1200 mm | 10-8000 kg |
| Discs and tube sheets | Ø 100-3000 mm, thickness 20-800 mm | 5-10000 kg |
| Shafts and bars | Ø 60-800 mm, length up to 8000 mm | 5-10000 kg |
| Sleeves and hollow bars | OD 120-1500 mm, ID from 60 mm | 10-5000 kg |
| Blocks and flat forgings | up to 1200 × 800 mm section | up to 10000 kg |

Sizes outside this range can often be produced. Minimum order quantity is one piece; prototype and single part orders are accepted.

## Manufacturing route

1. **Melting.** Electric arc furnace with VOD refining. Electroslag remelting is added where the order requires it, and is normally specified for pressure retaining and rotating components to reduce segregation and improve cleanliness.
2. **Cogging and upsetting.** The ingot is cogged and upset to break down the as-cast structure. The reduction ratio is set against the finished section size rather than against the ingot size.
3. **Open-die forging.** Forging between approximately 1200 °C and 980 °C, with reheating as required. Finish forging is completed above the recrystallisation temperature.
4. **Solution annealing.** Typically 1100 to 1180 °C followed by rapid cooling, to dissolve chromium and titanium carbides and to develop a grain size of ASTM 5 or coarser. No ageing treatment is applied, because the alloy is solid solution strengthened.
5. **Machining.** Rough machining to drawing with an agreed allowance, or finish machining including bores, faces, grooves and flange facings.
6. **Testing and release.** Chemical analysis, mechanical testing, grain size determination, ultrasonic testing and a dimensional report, followed by certification and packing for sea or air freight.

## Testing, inspection and certification

Each X5NiCrAlTi31-20 forging is supplied with a certificate traceable to the heat number.

| Test | Method | Scope |
|---|---|---|
| Chemical analysis | Spectrometer, per heat | Standard |
| Tensile test | EN ISO 6892-1 / ASTM E8 | Standard |
| Grain size | ASTM E112 | Standard for this grade |
| Hardness | Brinell | Standard |
| Ultrasonic testing | EN 10228-4, ASTM A388, SEP 1921 | To customer class |
| Positive material identification | Portable XRF or OES | On request |
| Elevated temperature tensile | EN ISO 6892-2 | On request |
| Intergranular corrosion | ASTM A262 / ASTM G28 | On request |
| Dye penetrant | ASTM E165 / EN ISO 3452 | On request |
| Certificate | EN 10204 3.1 | Standard |
| Third party certificate | EN 10204 3.2 | SGS, BV, TÜV, Lloyd's on request |

**Ultrasonic testing standard for austenitic forgings.** EN 10228-3 applies to ferritic and martensitic steel forgings. X5NiCrAlTi31-20 is austenitic, so the applicable European standard is EN 10228-4. Drawings sometimes specify Part 3 for this grade; where that occurs it is raised at order review before testing.

## Applications

X5NiCrAlTi31-20 is used where metal temperatures remain above approximately 600 °C for long periods, and in carburising or oxidising atmospheres in which stainless steels have limited service life.

- **Steam reformers.** Outlet manifolds, headers, pigtail fittings and flanges.
- **Ethylene and cracking furnaces.** Return bends, hangers and supports.
- **Ammonia and methanol plant.** Reformer and waste heat components.
- **Heat treatment plant.** Muffles, retorts, radiant tube components, fixtures and baskets.
- **Power generation.** Superheater and HRSG headers and hot gas components.
- **Sulphuric acid regeneration.** Furnace internals.
- **Valves and pressure parts.** High temperature valve seat rings, bodies and stems.
- **Heat exchangers.** Tube sheets, shell flanges and nozzles.

Alloy 800H is also a candidate material for heat exchanger and structural components in Generation IV reactor designs, including high temperature gas cooled and supercritical water cooled systems.

## How to order

Quotations are normally issued within one working day.

1. **Send the drawing or the dimensions.** Email sales@steelforgepieces.com. For rings give OD, ID and height; for discs give diameter and thickness; for shafts give diameter and length. State whether the sizes given are finished or forged.
2. **State the governing standard.** EN (1.4958), ASTM and ASME (N08810), or dual certification.
3. **List the test scope and certificate.** Tensile, grain size, ultrasonic class, PMI, intergranular corrosion, EN 10204 3.1 or 3.2, and the third party agency if one is required.
4. **Confirm quantity and delivery condition.** Solution annealed as forged, rough machined or finish machined, together with the destination port.

## Questions and answers

**What is X5NiCrAlTi31-20?**
X5NiCrAlTi31-20 is the EN chemical designation of the iron-nickel-chromium heat resistant alloy with material number 1.4958. It contains 30.0 to 32.5 percent nickel and 19.0 to 22.0 percent chromium with controlled aluminium and titanium, and is the European equivalent of Alloy 800H (UNS N08810). It is solution annealed to a grain size of ASTM 5 or coarser so that it retains creep and stress rupture strength above 593 °C.

**Is X5NiCrAlTi31-20 the same as Incoloy 800H?**
They are the same alloy under different standards. 1.4958 is the European designation and N08810 or Alloy 800H the American one. The practical difference is the carbon range: EN 10088-1 specifies 0.03 to 0.08 percent, ASTM specifies 0.05 to 0.10 percent. A single heat certified to both must fall between 0.05 and 0.08 percent. Incoloy is a registered trademark of Special Metals Corporation and is used here only to identify the equivalent grade.

**What is the difference between Alloy 800, 800H and 800HT?**
Alloy 800 (1.4876 / N08800) is the fine grained base grade for service up to about 593 °C. Alloy 800H (X5NiCrAlTi31-20 / 1.4958 / N08810) has controlled higher carbon and is annealed above 1100 °C to a grain size of ASTM 5 or coarser for creep service above 593 °C. Alloy 800HT (X8NiCrAlTi32-21 / 1.4959 / N08811) adds a combined aluminium plus titanium requirement of 0.85 to 1.20 percent for the highest rupture strength of the three.

**Which forged shapes can be made in X5NiCrAlTi31-20?**
Seamless rolled rings, forged rings, discs, tube sheets, shafts, stepped shafts, flanges, sleeves, bushings, hollow bars, round bars, blocks, valve bodies, seat rings and nozzles. All are forged to customer drawing.

**What heat treatment do X5NiCrAlTi31-20 forgings receive?**
Solution annealing, typically 1100 to 1180 °C followed by rapid cooling, to dissolve chromium and titanium carbides and to develop a grain size of ASTM 5 or coarser. The grade is solid solution strengthened and is not age hardened, so no ageing treatment is applied.

**What are the minimum room temperature properties?**
In the solution annealed condition the commonly specified minima are 450 MPa tensile strength, 170 MPa 0.2 percent proof strength and 30 percent elongation, with a grain size of ASTM 5 or coarser. The governing values for an individual order are those in the applicable standard and on the mill certificate.

**What certification is supplied with the forgings?**
EN 10204 3.1 as standard. EN 10204 3.2 with third party inspection by SGS, BV, TÜV or Lloyd's is available on request. Ultrasonic testing is carried out to EN 10228-4, the part of the standard covering austenitic forgings, or to ASTM A388 or SEP 1921 as specified by the customer.

**What is the lead time and the minimum order quantity?**
Minimum order quantity is one piece, and single prototype forgings are accepted. Lead time depends on ingot size and machining scope and is confirmed with the quotation.

**Who supplies X5NiCrAlTi31-20 forgings?**
Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, forges X5NiCrAlTi31-20 (1.4958 / Alloy 800H) to customer drawing and ships worldwide. Enquiries: sales@steelforgepieces.com, telephone +86-189-2135-9659.

## About the manufacturer

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. The plant produces forgings to customer drawing in carbon steel, alloy steel, tool steel, stainless steel and nickel alloys. The nickel alloy range covers the Incoloy, Inconel, Hastelloy, Monel, Nimonic and Haynes families as well as X5NiCrAlTi31-20.

Forgings are produced to order rather than supplied from stock. Each enquiry is reviewed for ingot size, forging route, reduction ratio, heat treatment and test plan before a price is issued. Export documentation, EN 10204 certification and third party inspection are available.

## Related grades

Incoloy 800H, Incoloy 800HT, Incoloy 800, Incoloy 825, Inconel 600, Inconel 601, Inconel 617, Inconel 625, Inconel 718, Hastelloy C-276, Hastelloy X, Haynes 230, Monel 400, Nimonic 80A, Waspaloy.

Full list: https://www.steelforgepieces.com/Nickel-Alloy/

## How to cite this page

Jiangyin Jiangnan Metal Co., Ltd. (2026). X5NiCrAlTi31-20 (1.4958 / Alloy 800H) Forgings: Composition, Properties and Product Forms. https://www.steelforgepieces.com/Nickel-Alloy/X5NiCrAlTi31-20.html. Open-die forging factory, Jiangyin, Jiangsu, China. Updated 2 September 2026.

This page may be quoted and referenced provided Jiangyin Jiangnan Metal Co., Ltd. is named as the source.

## Sources

- EN 10088-1:2023, Stainless steels, Part 1: List of stainless steels
- EN 10095, Heat resisting steels and nickel alloys
- EN 10302, Creep resisting steels, nickel and cobalt alloys
- ASTM B564, Standard Specification for Nickel Alloy Forgings
- ASTM B408, Standard Specification for Nickel-Iron-Chromium Alloy Rod and Bar
- ASME Boiler and Pressure Vessel Code, Sections I, III and VIII
- VdTÜV Werkstoffblatt 412 and 434
- VDM Metals, Alloy 800 H/HP data sheet