Seamless rolled rings
Ring rolled to size, grain flow following the circumference. Retaining rings and bearing rings included.
Alloy 28 Forgings, UNS N08028 / EN 1.4563
X1NiCrMoCu31-27-4 · Z2NCDU31-27 · 02Ch27N31M4 · Nicrofer 3127 LC · Remanit 4563 · Sanicro 28 grade
Summary. Alloy 28 is an austenitic special steel with molybdenum and copper additions, carrying 26 to 28 % chromium, 30 to 34 % nickel, 3 to 4 % molybdenum and 0.6 to 1.5 % copper. It gives good resistance to sulphuric and phosphoric acids, high resistance to pitting and crevice corrosion, and high resistance to stress corrosion cracking. Corrosion resistance is better than 904L / 1.4539, and the steel resists intergranular corrosion in the delivery condition.
Jiangyin Jiangnan Metal Co., Ltd. forges Alloy 28 as seamless rolled rings, flanges, discs, shafts, sleeves, bushings, tube sheets, bars and shapes to drawing. Parts are solution annealed and water quenched, ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388, and certified to EN 10204 3.1 or 3.2. Send sizes or a drawing to sales@steelforgepieces.com or call 0086-189-2135-9659 for a price.
Seamless rolled ringsForged flangesForged shafts
Discs and blanksSleeves and bushingsTube sheets
Round and hollow barsValve partsOpen-die shapes
Grade description
Alloy 28 was developed for service in sour gas and in phosphoric, sulphuric and acetic acids and vinyl chloride. Typical equipment includes heat exchangers, coolers, tanks, pumps and pipelines in the chemical, cryogenic, paper, petrochemical and energy industries, together with parts for offshore platforms, screws and valves. The combination of molybdenum and nickel also helps prevent cracking caused by polythionic acid attack during plant start up and shut down, which is why the grade is common in acid plant evaporator service.
Resistance to stress corrosion cracking is excellent, in particular in hot chloride environments, and the high nickel level is the main reason. Because the carbon level is low and the steel is supplied solution annealed, it resists intergranular corrosion as delivered, without stabilising elements.
Designations and equivalents
| System | Designation |
|---|---|
| UNS | N08028 |
| EN number | 1.4563 |
| EN name | X1NiCrMoCu31-27-4 (also written X1NiCrMoCuN31-27-4) |
| France, NF | Z2NCDU31-27 |
| GOST | 02Ch27N31M4 / 0227314 |
| Trade names in circulation | Sanicro 28, Nicrofer 3127 LC, Remanit 4563, Nirosta 4563, Maresist 28, Tecronimo 28-31-4 |
| Data basis for EN grade | EN 10088-1, ISO 21457 |
Chemical composition
| 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 to 28.0 | 26.0 to 28.0 | 26.0 to 28.0 |
| Ni | 30.0 to 32.0 | 30.0 to 34.0 | 29.5 to 32.5 |
| Mo | 3.0 to 4.0 | 3.0 to 4.0 | 3.0 to 4.0 |
| Cu | 0.7 to 1.5 | 0.6 to 1.4 | 0.6 to 1.4 |
| N | < 0.1 | not specified | not specified |
Copper is part of the design of this grade and must appear on the certificate. A composition table without copper is incomplete. Melting at our works is by electric arc furnace with VOD refining, and electroslag remelting is available for critical forgings.
Mechanical properties of forgings
| Property | Value |
|---|---|
| Yield strength Re | above 220 MPa |
| Tensile strength Rm | 500 to 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 |
| 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 E | 195 GPa at 20 °C, 190 at 100 °C, 182 at 200 °C, 174 at 300 °C, 166 at 400 °C, 158 at 500 °C |
| Coefficient of linear expansion | 15.8 x10-6/K at 20 and 100 °C, 16.1 at 200 °C, 16.5 at 300 °C, 16.9 at 400 °C, 17.3 at 500 °C |
Forging, heat treatment, welding and machining
| Operation | Parameters |
|---|---|
| Forging | 1150 to 850 °C |
| Hot rolling | 1150 to 850 °C |
| Solution annealing | 1050 to 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 that the grade is bought for drops. Every batch here is solution annealed and water quenched, then tested after heat treatment rather than before.
Welding
The alloy belongs to welding group ISO 8.2 and preheating is not necessary. Filler metals 1.4562 and 2.4621 suit the grade. Where a vessel is built 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 get particular attention under that Case.
Machining
Alloy 28 work hardens, so cutting speed is reduced against 316 and 316L when turning with coated cemented carbide tools. Feeds are cut back only slightly and with care, because a light feed lets the tool rub and harden the surface ahead of the cut. Rigid setups, sharp tooling and plenty of 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 the composition and property requirements agreed on the purchase order or the customer specification |
If the job needs a named forging specification, or qualification to NACE MR0175 / ISO 15156 for sour service, state it on the enquiry. We confirm in writing what can be certified before the order is placed rather than after.
Forged products in Alloy 28
Forged flanges
Weld neck, slip on, blind and special profiles for pressure piping and vessel nozzles.
Shafts and spindles
Pump, agitator and compressor shafts, straight or stepped, plus eccentric shafts.
Discs, blanks and tube sheets
Heat exchanger tube sheets, covers, discs and blanks left with machining allowance.
Sleeves and bushings
Hollow forgings, bored or trepanned, for wear and corrosion duty.
Bars and billets
Forged round, square and flat bars, gear blanks and rolls.
Valve components
Bodies, bonnets, stems, seat rings and blocks for ball, gate, globe, check and plug valves.
Open-die parts to drawing
Nozzles, manifolds, crankshafts, wheels and one-off shapes.
Where these forgings are used
Phosphoric and sulphuric acid plants and other chemical and petrochemical process equipment take most of the output. The rest goes to pressure vessels, air receivers and shell and tube heat exchangers, to downhole and wellhead equipment in moderately corrosive deep sour gas wells, to subsea and deepwater production systems, to seawater and chloride bearing cooling circuits, to pulp, paper, pharmaceutical and biochemical plant, and to pumps, compressors and gearboxes where strength has to come with chloride cracking resistance.
Testing and documents
Composition is checked by spectrometer on each heat and by PMI on the finished part when asked. Mechanical testing follows final solution annealing. Ultrasonic testing is carried out to EN 10228-3, SEP 1921 or ASTM A388 at the acceptance class named on the order, and a dimensional report is issued against the drawing. Certificates are supplied as EN 10204 3.1, or EN 10204 3.2 verified by SGS, BV, TUV or the inspector you nominate. Hardness survey, intergranular corrosion testing, pitting tests and sub-zero impact testing can be added.
Questions we are asked about this grade
What is Alloy 28?
An austenitic special steel with molybdenum and copper additions, 26 to 28 % chromium, 30 to 34 % nickel, 3 to 4 % molybdenum and 0.6 to 1.5 % copper. It gives good resistance to sulphuric and phosphoric acids, high resistance to pitting and crevice corrosion, and high resistance to stress corrosion cracking. It is widely used for evaporator tubing in acid plants and for pipes in oil and gas production.
What are the mechanical properties of Alloy 28 forgings?
In the hot worked and solution annealed condition, forgings in 1.4563 give yield strength Re above 220 MPa, tensile strength Rm of 500 to 700 MPa, elongation A above 40 % and hardness below 230 HB. Impact energy KV at 20 °C is above 100 J longitudinal and above 60 J transverse, and transverse impact energy stays above 60 J at minus 196 °C.
How is Alloy 28 forged and heat treated?
Forged and hot rolled between 1150 °C and 850 °C, then solution annealed at 1050 to 1150 °C and quenched in water. Fast cooling from the solution annealing temperature is needed so that secondary phases do not precipitate and reduce corrosion resistance.
Which standards cover UNS N08028?
ASTM B668 covers seamless cold finished or hot finished pipe and tube for general corrosive service. ASTM B709 covers plate, sheet and strip in the solution annealed condition. ASME Code Case 1325 addresses N08028 and requires gas tungsten arc welding only. EN 10088-1 and ISO 21457 are the basis for the 1.4563 data. Forged shapes are supplied to the requirements agreed on the purchase order or to the customer specification.
Is Alloy 28 better than 904L?
Alloy 28 has better corrosion resistance than UNS N08904 / 904L / 1.4539, mainly because of its higher chromium and nickel content. It resists intergranular corrosion in the delivery condition and performs well against stress corrosion cracking in hot chlorides. Where the duty is milder, 904L is the cheaper choice and we forge that as well.
Can Alloy 28 be welded?
Yes. The alloy belongs to welding group ISO 8.2 and preheating is not necessary. Suitable filler metals are 1.4562 and 2.4621. Where construction follows ASME Code Case 1325 for N08028, welding is restricted to the gas tungsten arc process only.
What forged shapes and certificates does Jiangyin Jiangnan Metal supply in Alloy 28?
Seamless rolled rings, forged flanges, discs and blanks, round and hollow bars, shafts, sleeves, bushings, tube sheets, nozzles, valve bodies, stems and seat rings, and open-die shapes made to customer drawings. Ultrasonic testing is to EN 10228-3, SEP 1921 or ASTM A388 as agreed, with certificates to EN 10204 3.1 or EN 10204 3.2 verified by a third party. The factory is at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. Enquiries: sales@steelforgepieces.com, 0086-189-2135-9659.
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 classed as a high alloy austenitic stainless steel, while the N08xxx UNS number leads other suppliers 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 to deal with sour gas and is used downhole in moderately corrosive deep sour gas wells. Whether a particular part qualifies for your H2S partial pressure, chloride level and temperature has to be assessed against NACE MR0175 / ISO 15156, so give us the service conditions with the enquiry.
How low in temperature can it go?
Transverse impact energy stays above 60 J at minus 196 °C, so the steel keeps its toughness into cryogenic service. The grade is listed for cryogenic plant alongside chemical and petrochemical use.
Request a price for Alloy 28 forgings
Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Tel 0086-189-2135-9659
Email sales@steelforgepieces.com
Send the size or drawing of the Alloy 28 forging you need and we will quote our best price. Give the grade, quantity, delivery condition, as forged or rough machined or finish machined, plus NDT and certificate requirements. A quotation normally follows within one working day.
Composition, mechanical and physical data on this page follow published 1.4563 and UNS N08028 datasheets and the scopes of EN 10088-1, ISO 21457, ASTM B668, ASTM B709 and ASME Code Case 1325. Figures are for guidance. Order specific values are confirmed on the material certificate. Updated 2 October 2026. A plain text version of this page is at Alloy-28.md.