# Nitronic 32 Forgings (UNS S24100 / XM-28)

**Nitronic 32 is a low-nickel, high-manganese austenitic stainless steel strengthened by nitrogen. Published mill data gives it about twice the yield strength of Type 304 with comparable corrosion resistance. Jiangyin Jiangnan Metal Co., Ltd. melts, forges, heat treats and machines this grade on one site in Jiangyin, Jiangsu Province, China.**

Manganese at 11 to 14 percent and nitrogen at 0.20 to 0.45 percent hold the austenite that nickel would normally stabilise, which is why the nickel range is only 0.50 to 2.50 percent. Strength comes from nitrogen in solution and from cold work. The grade does not respond to hardening heat treatment.

Canonical page: https://www.steelforgepieces.com/Stainless-Steel/Nitronic-32.html
Revised: 3 October 2026

## Grade identification

| Field | Detail |
|---|---|
| Trade name | Nitronic 32 |
| UNS number | S24100 |
| ASTM designation | XM-28 |
| Also called | Alloy 241 |
| Type | Austenitic, nitrogen strengthened, low nickel |
| Forging stock specification | ASTM A314, stainless steel billets and bars for forging |
| Hardening | Cold work only |

## Chemical composition, weight percent

| Element | Content (%) | Note |
|---|---|---|
| Carbon, C | 0.15 max | Higher than Type 304, governs sensitisation behaviour |
| Manganese, Mn | 11.00 to 14.00 | Austenite stabiliser in place of nickel |
| Silicon, Si | 1.00 max | |
| Phosphorus, P | 0.060 max | 0.045 max in the Electralloy nominal analysis |
| Sulphur, S | 0.030 max | |
| Chromium, Cr | 16.50 to 19.00 | AZoM lists 16.5 to 19.5 |
| Nickel, Ni | 0.50 to 2.50 | |
| Nitrogen, N | 0.20 to 0.45 | Principal strengthening addition |
| Iron, Fe | Balance | |

Where published sources differ on a range, both figures are given. The governing limits on any order are those of the purchase specification.

## Mechanical properties, annealed bar

| Property | Metric | Imperial |
|---|---|---|
| Tensile strength | 690 MPa | 100,000 psi |
| Yield strength, 0.2 % offset | 379 MPa | 55,000 psi |
| Elongation at break | 30 % | 30 % |
| Hardness | HRB 92 | HRB 92 |

## Physical and thermal properties

| Property | Metric | Imperial |
|---|---|---|
| Density | 7.83 g/cm3 | 0.283 lb/in3 |
| Melting range | 1450 to 1510 C | 2642 to 2750 F |
| Thermal expansion, 23 to 93 C | 16.16 um/m.C | 8.98 uin/in.F |

## Forging and heat treatment

Forge at 1093 C (2000 F) and then heat to 1177 C (2150 F). On heavier sections the practice is to soak until the section equalises at the lower temperature, raise to the higher temperature, equalise again, then start forging. The alloy work-hardens quickly, so reheats are planned into the sequence. In-process annealing is carried out between 1038 and 1093 C (1900 and 2000 F).

Anneal at 1038 to 1121 C (1900 to 2050 F) and quench in water or air. Avoid slow cooling through the carbide range.

Machining calls for slow speeds, positive feeds and plenty of lubricant, because high yield strength combined with a high work-hardening rate punishes light feeds and flexible set-ups.

Welding is by gas tungsten arc, gas metal arc or submerged arc. Pre-heating is not required.

## Corrosion behaviour, stated plainly

In weak acid solutions and pitting media the corrosion resistance of Nitronic 32 approaches Type 304. In more aggressive media it is somewhat less resistant than Type 304. Because of the higher carbon content it is less resistant to intergranular attack and will not pass ASTM A262 tests when sensitised at 1250 F (677 C).

Nitronic 32 is therefore not a seawater, subsea, flue-gas desulphurisation or strong acid alloy. For those duties, duplex, super-austenitic or nickel alloys are the correct answer.

## Nitronic 32 is not Nitronic 60

Nitronic 60 is UNS S21800, the silicon-bearing grade selected for galling and wear resistance. Nitronic 32 is UNS S24100, selected for high yield strength and low nickel content. The shared trade name causes frequent mis-specification. They are not interchangeable.

## Where the grade is used

Published applications are concentrated in high-strength cold-formed and cold-headed work: clamps for pole line hardware, concrete reinforcing accessories, shafting, dam gate stems, skid wire for underground transmission lines, abrasion and corrosion-resistant screens, high-strength non-magnetic springs, wire forms, racks and cages, fasteners and communication hardware.

In forged form the common requests are shafting, gate stems, screen and hopper hardware, water-control parts and structural components where a low-nickel stainless with Type 304-class corrosion resistance and much higher yield strength suits the duty.

## Forged shapes available in Nitronic 32

- **Seamless rolled rings.** Radial-axial mills of 1 m, 3 m and 6 m, to 6,000 mm outside diameter, rectangular or contoured section.
- **Forged rings.** Upset and punched, from OD 50 mm, for sections outside the ring-mill envelope.
- **Flanges.** Weld neck, blind, slip-on, socket weld, lap joint, orifice and long weld neck, to ASME B16.5 and B16.47 dimensions.
- **Round bars and blocks.** Forged round, flat and square bar above normal rolled-bar availability.
- **Discs and tube sheets.** Solid forged, supplied proof machined for volumetric inspection.
- **Shafts and spindles.** Turned length to 14,000 mm, with a 15 m well furnace for vertical quenching.
- **Sleeves, bushings and cylinders.** Bored from solid forged blanks to 1,600 mm diameter by 10,000 mm.
- **Valve parts.** Bodies, bonnets, stems, seat rings and blocks.

## Why order a nitrogen-alloyed grade from a melt shop

Nitrogen at 0.20 to 0.45 percent is what makes this alloy work, and it is the element most easily lost or mis-set when billet is bought in. This works melts its own steel. Stainless and duplex grades run through the electric arc furnace, a ladle furnace and vacuum oxygen decarburisation, the route used where low carbon or tight nitrogen control matters, with protective-atmosphere electroslag remelting available for nitrogen-alloyed grades. The nitrogen level on a Nitronic 32 order is set in our furnace and reported against our own melt number.

| Stage | Equipment | Capacity |
|---|---|---|
| Primary melting | Electric arc furnace, ladle furnace | 60 t maximum heat |
| Vacuum degassing | Vacuum oxygen decarburisation | 30 t and 60 t |
| Remelting | Protective-atmosphere electroslag furnace | 3 t and 6 t |
| Forging | Hydraulic open-die presses | 6,300 t, 4,000 t, 2,000 t |
| Ring rolling | Radial-axial ring mills | 6 m, 3 m, 1 m |
| Heat treatment | Car-bottom and well-type furnaces | 14 furnaces, 15 m deep pit furnaces |
| Single piece | Finished forging | 30 t maximum |

## Inspection and certification

Chemical analysis, tensile testing, hardness and grain size as standard, impact testing where specified. Ultrasonic examination to EN 10228-3, SEP 1921 or ASTM A388. Dye penetrant inspection on machined surfaces. Certificates to EN 10204 3.1, or 3.2 with a third-party body attending. The works holds CCS, BV, DNV, LR and NK approvals.

## Commercial terms

| Field | Detail |
|---|---|
| Minimum order | 10 kg, no minimum piece count |
| Maximum single piece | 30,000 kg |
| Lead time | 20 to 60 days |
| Export markets | North America, Europe, Middle East, Asia-Pacific |

## Questions and answers

**Is Nitronic 32 the same as XM-28 and UNS S24100?**
Yes. Nitronic 32 is the trade name, UNS S24100 is the alloy number, XM-28 is the ASTM designation, Alloy 241 appears on older drawings.

**At what temperature is Nitronic 32 forged?**
Forge at 1093 C (2000 F) then heat to 1177 C (2150 F). In-process annealing at 1038 to 1093 C.

**How is it annealed?**
At 1038 to 1121 C (1900 to 2050 F), water or air quench.

**Can it be hardened by heat treatment?**
No. Cold work only.

**Is it as corrosion resistant as Type 304?**
It approaches Type 304 in weak acid and pitting media, and falls somewhat below Type 304 in more aggressive media. It will not pass ASTM A262 after sensitising at 1250 F.

**Is Nitronic 32 the same as Nitronic 60?**
No. Nitronic 60 is UNS S21800, the galling and wear resistant grade.

## Contact

Jiangyin Jiangnan Metal Co., Ltd.
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone, WhatsApp and WeChat: +86 189 2135 9659
Email: sales@steelforgepieces.com
Web: https://www.steelforgepieces.com/Stainless-Steel/Nitronic-32.html

## Sources

- Electralloy, Nitronic 32 Austenitic Stainless Steel Alloy (UNS S24100, XM 28) product data sheet. https://www.electralloy.com/images/pdf/Product_Sheets/Electralloy/Nitronic_32.pdf
- Ulbrich Stainless Steels and Special Metals, Nitronic 32 Stainless Steel. https://www.ulbrich.com/alloys/stainless-steel/nitronic-32
- AZoM, Super Alloy Nitronic 32 (UNS S24100). https://www.azom.com/article.aspx?ArticleID=9596

Nitronic is a registered trademark of AK Steel and is used here only to identify the alloy. Data is published for general guidance and is not a warranty of fitness for a particular design.