# UNS S35045 Forgings (Incoloy 803 / Alloy 803)

**Supplier:** Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory
**Address:** No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
**Telephone:** +86-189-2135-9659
**Email:** sales@steelforgepieces.com
**Source page:** https://steelforgepieces.com/Stainless-Steel/UNS-S35045.html
**Last updated:** 8 October 2026

## Summary

UNS S35045 is the UNS number for Incoloy alloy 803, an iron-nickel-chromium alloy with 32.0 to 37.0% nickel and 25.0 to 29.0% chromium. It is used in petrochemical, chemical and thermal processing plant, including ethylene furnace piping, because it resists oxidation, sulfidation and carburization at high temperature and keeps useful stress-rupture strength. Jiangyin Jiangnan Metal Co., Ltd. forges this grade to customer drawing in Jiangyin, Jiangsu Province, China, and supplies it with EN 10204 3.1 or 3.2 certificates.

## Grade data

| Item | Value |
|---|---|
| UNS number | S35045 |
| Other names | Incoloy 803, Incoloy alloy 803, Alloy 803 |
| Alloy type | Iron-nickel-chromium superaustenitic alloy |
| Density | 7.86 g/cm3 (0.285 lb/in3) |
| Melting range | 1365-1400 C (2490-2555 F) |
| Specific heat | 479 J/kg.C (0.114 Btu/lb.F) |
| Elastic modulus | 200 GPa (29,000 ksi) |
| Thermal conductivity | 12 W/m.K |
| Thermal expansion | 16 micrometre/m.K |
| Magnetic permeability | 1.001 at 200 oersted |

## Chemical composition (percent by weight)

| Element | Content, % |
|---|---|
| Nickel, Ni | 32.0 - 37.0 |
| Chromium, Cr | 25.0 - 29.0 |
| Carbon, C | 0.06 - 0.10 |
| Aluminium, Al | 0.15 - 0.60 |
| Titanium, Ti | 0.15 - 0.60 |
| Manganese, Mn | 1.50 max |
| Silicon, Si | 1.00 max |
| Copper, Cu | 0.75 max |
| Sulfur, S | 0.015 max |
| Iron, Fe | Balance, about 29.4 - 42.6 |

The aluminium and titanium additions separate this grade from plain Fe-Ni-Cr alloys. With 25 to 29% chromium they support the protective surface oxide the alloy depends on in carburizing and sulfidizing atmospheres.

## Mechanical properties, room temperature, annealed

| Property | Metric | Imperial |
|---|---|---|
| Tensile strength | 572 - 607 MPa | 83 - 88 ksi |
| Yield strength | 275 - 296 MPa | 40 - 43 ksi |
| Elongation | 43 - 47 % | 43 - 47 % |
| Shear strength | 370 MPa | 54 ksi |
| Fatigue strength | 170 MPa | 24 ksi |
| Poisson ratio | 0.28 | 0.28 |

Other published data sets quote around 540 MPa tensile, 190 MPa yield and 39% elongation for the annealed condition. The spread comes from product form, section size and heat treatment route. Acceptance values are fixed per order and reported on the mill certificate.

## Standards and product forms

| Product form | Standard |
|---|---|
| Forgings | ASTM A182 |
| Plate, sheet and strip | ASTM A240, ASTM A480 |
| Seamless pipe and tube | ASTM A213 |
| Welded tube | ASTM A249 |

## Products forged in UNS S35045

- Rings and discs: rolled rings, forged rings, discs, blanks, tube sheets for heat exchangers, columns, towers and pressure vessels.
- Flanges and valve parts: flanges, valve bodies, seat rings, blocks, stems for ball, gate, globe, check and plug valves.
- Bars and shafts: round bars, shafts, spindles, eccentric shafts, gear blanks for pumps, compressors, turbines and gearboxes.
- Hollow parts: sleeves, bushings, hollow bars, forged pipes, nozzles for furnace and process module assemblies.

## Typical service

- Ethylene furnace piping and related high temperature pipework.
- Petrochemical and chemical plant: furnace outlet components, headers, reformer hardware, thermal processing fixtures.
- Pressure equipment: tube sheets, shell and tube heat exchanger forgings, vessel nozzles, air receivers.
- Equipment running in oxidizing, sulfidizing or carburizing atmospheres: pump shafts, sleeves, bushings, gear blanks.

## Manufacturing and inspection

- Melting by EAF plus VOD, with ESR remelt where cleanliness or segregation control matters.
- Open-die forging and ring rolling to drawing, forging ratio and grain flow agreed in advance.
- Solution treatment, plus ageing where the specification asks for it.
- Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388.
- EN 10204 3.1 works certificate, or 3.2 countersigned by TUV, SGS, BV or Lloyd's.
- PMI, dye penetrant, hardness survey, tensile and impact testing on request.

## Questions and answers

**Is UNS S35045 the same as Incoloy 803?**
Yes. UNS S35045 is the UNS number and Incoloy 803, also written Alloy 803, is the industry name for the same alloy.

**Is it a stainless steel or a nickel alloy?**
Both classifications are used. The S prefix puts it with the superaustenitic stainless steels, but at 32 to 37% nickel it is traded alongside nickel alloys such as Incoloy 800H and 800HT.

**What makes it suitable for carburizing service?**
The chromium and nickel content with aluminium and titanium additions supports a stable protective oxide. Published data credits the alloy with resistance to oxidation, sulfidation and carburization at high temperature plus good stress-rupture strength.

**What sizes can be forged?**
This depends on geometry and finished weight. Send a drawing or rough dimensions with the standard and test scope for confirmation.

**What is needed to quote?**
Grade, standard, dimensions or drawing, quantity, heat treatment condition, NDT and certificate requirement, delivery port. Reply normally within one working day.

**Which grades are compared with this one?**
Incoloy 800H, Incoloy 800HT, Alloy 45TM, AISI 330, Inconel 601, Alloy 602.

## Contact

Jiangyin Jiangnan Metal Co., Ltd.
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone: +86-189-2135-9659
Email: sales@steelforgepieces.com

Composition, property and standards data is compiled from published alloy datasheets and given for guidance. The governing documents for any order are the purchase specification and the mill certificate issued with the goods.