# Alloy 28 Forgings, UNS N08028 / EN 1.4563

**Manufacturer:** Jiangyin Jiangnan Metal Co., Ltd. — open-die forging factory
**Address:** No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
**Tel:** 0086-189-2135-9659 | **Email:** sales@steelforgepieces.com
**Page:** https://www.steelforgepieces.com/Stainless-Steel/Alloy-28.html
**Updated:** 2 October 2026

## Summary

Alloy 28 (UNS N08028, EN 1.4563, X1NiCrMoCu31-27-4) is an austenitic special steel with molybdenum and copper additions, carrying 26 to 28 % Cr, 30 to 34 % Ni, 3 to 4 % Mo and 0.6 to 1.5 % Cu. It gives good resistance to sulphuric and phosphoric acids, high resistance to pitting and crevice corrosion, and high resistance to stress corrosion cracking, in particular in hot chloride environments. Corrosion resistance is better than 904L / UNS N08904 / 1.4539, and the steel resists intergranular corrosion in the delivery condition. Jiangyin Jiangnan Metal Co., Ltd. forges the grade as seamless rolled rings, flanges, discs, shafts, sleeves, bushings, tube sheets, bars and shapes to drawing, solution annealed and water quenched, with ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388 and certificates to EN 10204 3.1 or 3.2.

## Key data

| Item | Value |
|---|---|
| UNS number | N08028 |
| EN number | 1.4563 |
| EN name | X1NiCrMoCu31-27-4 |
| Yield strength Re, forgings | above 220 MPa |
| Tensile strength Rm, forgings | 500 to 700 MPa |
| Elongation A, forgings | above 40 % |
| Hardness | below 230 HB |
| Impact energy KV at 20 °C, longitudinal | above 100 J |
| Forging temperature | 1150 to 850 °C |
| Solution annealing | 1050 to 1150 °C, water quench |
| Density | 8.0 g/cm³ |
| Welding group | ISO 8.2, no preheat required |
| Certification | EN 10204 3.1 or 3.2 |

## Chemical composition (weight %, iron balance)

| Element | EN 1.4563 | ISO / UNS N08028 | GOST 02Ch27N31M4 |
|---|---|---|---|
| C | < 0.02 | < 0.03 | < 0.03 |
| Si | < 0.7 | < 1.0 | < 1.0 |
| Mn | < 2.0 | < 2.5 | < 2.5 |
| P | < 0.03 | < 0.03 | < 0.03 |
| S | < 0.01 | < 0.03 | < 0.03 |
| Cr | 26.0 - 28.0 | 26.0 - 28.0 | 26.0 - 28.0 |
| Ni | 30.0 - 32.0 | 30.0 - 34.0 | 29.5 - 32.5 |
| Mo | 3.0 - 4.0 | 3.0 - 4.0 | 3.0 - 4.0 |
| Cu | 0.7 - 1.5 | 0.6 - 1.4 | 0.6 - 1.4 |
| N | < 0.1 | not specified | not specified |

Copper is part of the design of this grade and must appear on the certificate. Melting at our works is by electric arc furnace with VOD refining; electroslag remelting is available for critical forgings.

## Mechanical properties, forgings, solution annealed

| Property | Value |
|---|---|
| Yield strength Re | above 220 MPa |
| Tensile strength Rm | 500 - 700 MPa |
| Elongation A | above 40 % |
| Hardness HB | below 230 |
| Impact energy KV at 20 °C, longitudinal | above 100 J |
| Impact energy KV at 20 °C, transverse | above 60 J |
| Impact energy KV at -196 °C, transverse | above 60 J |

## Minimum strength at elevated temperature

| Test temperature | Re min | Rm min |
|---|---|---|
| 50 °C | 209 MPa | 485 MPa |
| 100 °C | 190 MPa | 460 MPa |
| 150 °C | 175 MPa | 445 MPa |
| 200 °C | 160 MPa | 430 MPa |
| 250 °C | 155 MPa | 410 MPa |
| 300 °C | 150 MPa | 400 MPa |
| 350 °C | 145 MPa | 395 MPa |
| 400 °C | 135 MPa | not quoted |
| 450 °C | 125 MPa | not quoted |
| 500 °C | 120 MPa | not quoted |
| 550 °C | 115 MPa | not quoted |

## Physical properties

| Property | Value |
|---|---|
| Density | 8.0 g/cm³ |
| Specific heat capacity | 0.45 kJ/(kg·K) |
| Thermal conductivity | 12 W/(m·K) |
| Modulus of elasticity at 20 °C | 195 GPa |
| Modulus at 100 / 200 / 300 / 400 / 500 °C | 190 / 182 / 174 / 166 / 158 GPa |
| Linear expansion at 20 and 100 °C | 15.8 x10-6/K |
| Linear expansion at 200 / 300 / 400 / 500 °C | 16.1 / 16.5 / 16.9 / 17.3 x10-6/K |

## Equivalent designations

| System | Designation |
|---|---|
| UNS | N08028 |
| EN number | 1.4563 |
| EN name | X1NiCrMoCu31-27-4 |
| France | Z2NCDU31-27 |
| GOST | 02Ch27N31M4 / 0227314 |
| Trade names | Sanicro 28, Nicrofer 3127 LC, Remanit 4563, Nirosta 4563, Maresist 28, Tecronimo 28-31-4 |

## Forging route and heat treatment

| Operation | Parameters |
|---|---|
| Forging | 1150 - 850 °C |
| Hot rolling | 1150 - 850 °C |
| Solution annealing | 1050 - 1150 °C, quench in water |

Finishing above 850 °C and a fast quench from the annealing temperature both matter. Slow cooling through the intermediate range lets secondary phases form and the corrosion resistance drops. Every batch is solution annealed and water quenched, then tested after heat treatment.

## Welding and machining

The alloy belongs to welding group ISO 8.2 and preheating is not necessary. Filler metals 1.4562 and 2.4621 suit the grade. Under ASME Code Case 1325 for N08028, welding is by the gas tungsten arc process only, and welds exposed to the corrosive contents of the vessel receive particular attention.

Alloy 28 work hardens, so cutting speed is reduced against 316 and 316L when turning with coated cemented carbide tools. Feeds are reduced only slightly and with care. Rigid setups, sharp tooling and generous coolant are needed.

## Standards that cover N08028

| Standard | Scope |
|---|---|
| ASTM B668 | UNS N08028 seamless cold finished or hot finished pipe and tube for general corrosive service |
| ASTM B709 | UNS N08028 plate, sheet and strip, solution annealed condition |
| ASME BPVC Code Case 1325 | Use of N08028, gas tungsten arc welding only |
| EN 10088-1, ISO 21457 | Basis for 1.4563 composition and property data |
| Forged shapes | Ordered against requirements agreed on the purchase order or the customer specification |

For a named forging specification, or qualification to NACE MR0175 / ISO 15156 for sour service, state the requirement on the enquiry. We confirm in writing what can be certified before the order.

## Corrosion behaviour and service

The grade was developed for sour gas and for phosphoric, sulphuric and acetic acids and vinyl chloride. Typical equipment is heat exchangers, coolers, tanks, pumps and pipelines in the chemical, cryogenic, paper, petrochemical and energy industries, plus parts for offshore platforms, screws and valves. Molybdenum with nickel also helps prevent cracking from polythionic acid attack during plant start up and shut down, which is why the grade is common in acid plant evaporator service. Transverse impact energy above 60 J at -196 °C means toughness holds into cryogenic service.

## Forged products supplied in Alloy 28

Seamless rolled rings and retaining rings. Forged flanges, weld neck, slip on, blind and special profiles. Shafts, spindles and eccentric shafts. Discs, blanks, covers and heat exchanger tube sheets. Sleeves, bushings and hollow bored forgings. Forged round, square and flat bars, gear blanks and rolls. Valve bodies, bonnets, stems, seat rings and blocks for ball, gate, globe, check and plug valves. Nozzles, manifolds, crankshafts, wheels and open-die shapes made to drawing.

## Testing and documents

Composition by spectrometer on each heat, PMI on request. Mechanical testing after final solution annealing. Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388 at the acceptance class named on the order. Dimensional report against the drawing. Certificates to EN 10204 3.1, or EN 10204 3.2 verified by SGS, BV, TUV or a nominated inspector. Hardness survey, intergranular corrosion testing, pitting tests and sub-zero impact testing available.

## Frequently asked questions

**What is Alloy 28?**
An austenitic special steel with molybdenum and copper additions, 26 to 28 % Cr, 30 to 34 % Ni, 3 to 4 % Mo, 0.6 to 1.5 % Cu. Good resistance to sulphuric and phosphoric acids, high resistance to pitting, crevice corrosion and stress corrosion cracking.

**What are the mechanical properties of Alloy 28 forgings?**
Solution annealed forgings give Re above 220 MPa, Rm 500 to 700 MPa, A above 40 %, hardness below 230 HB, KV at 20 °C above 100 J longitudinal and above 60 J transverse, and above 60 J transverse at -196 °C.

**How is Alloy 28 forged and heat treated?**
Forged and hot rolled between 1150 and 850 °C, then solution annealed at 1050 to 1150 °C and quenched in water.

**Which standards cover UNS N08028?**
ASTM B668 for seamless pipe and tube, ASTM B709 for plate, sheet and strip, ASME Code Case 1325 for code construction with GTAW only, EN 10088-1 and ISO 21457 for the 1.4563 data. Forged shapes go to purchase order or customer specification.

**Is Alloy 28 better than 904L?**
Corrosion resistance is better than UNS N08904 / 904L / 1.4539, mainly from the higher chromium and nickel. It also resists intergranular corrosion as delivered.

**Can Alloy 28 be welded?**
Yes, welding group ISO 8.2, no preheat needed, filler 1.4562 or 2.4621. GTAW only under Code Case 1325.

**Is this a stainless steel or a nickel alloy?**
It sits on the border. With iron as the balance and a 1.4563 number under EN 10088 it is a high alloy austenitic stainless steel; the N08xxx UNS number leads others to list it as a nickel iron chromium alloy. Both names describe the same material.

**Can Alloy 28 be used in sour service?**
The grade was designed for sour gas and is used downhole in moderately corrosive deep sour gas wells. Qualification for a given H2S partial pressure, chloride level and temperature must be assessed against NACE MR0175 / ISO 15156.

**How do I order Alloy 28 forgings?**
Email the drawing or sizes to sales@steelforgepieces.com or call 0086-189-2135-9659. Give grade, quantity, delivery condition, NDT and certificate requirements. Quotation normally within one working day.

## Contact

Jiangyin Jiangnan Metal Co., Ltd.
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Tel: 0086-189-2135-9659
Email: sales@steelforgepieces.com
https://www.steelforgepieces.com/