# Nitronic 30 (UNS S20400) Forgings

Nitronic 30 is a nitrogen and manganese strengthened austenitic stainless steel developed for applications needing a good level of aqueous corrosion resistance together with good toughness, wet abrasion resistance and low alloy cost. Jiangyin Jiangnan Metal Co., Ltd. forges it to customer drawing as rings, seamless rolled rings, flanges, round bars, shafts, discs, sleeves, bushings and tube sheets.

- Manufacturer: Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory
- Address: No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Telephone: 0086-189-2135-9659
- Email: sales@steelforgepieces.com
- Page: https://steelforgepieces.com/Stainless-Steel/Nitronic-30.html

## Grade data

| Item | Value |
| --- | --- |
| UNS number | S20400 |
| Structure | Austenitic |
| Strengthened by | Nitrogen and manganese |
| Molybdenum | None |
| Tensile strength, min | 655 MPa (95 ksi) |
| Yield strength, min | 330 MPa (48 ksi) |

Nitronic 30 gives about 50 percent higher yield strength than Type 304L, so lighter sections can carry the same load. It work hardens quickly and still holds good ductility. Nickel is held at 1.5 to 3.0 percent and no molybdenum is added, which makes it a low cost grade for wet abrasive and moderate water service rather than a high alloy corrosion grade.

### Where not to use it

Nitronic 30 is not a seawater, subsea, desalination or strong acid alloy and does not replace duplex or 6 Mo grades. For chloride bearing seawater, firewater, subsea pipework and FGD service, specify A182 F51, F53, F55, F44, 904L or Alloy 31. We forge those grades as well.

## Chemical composition, weight percent

| Element | Min | Max |
| --- | --- | --- |
| Carbon (C) | - | 0.03 |
| Manganese (Mn) | 7.0 | 9.0 |
| Phosphorus (P) | - | 0.040 |
| Sulfur (S) | - | 0.030 |
| Silicon (Si) | - | 1.00 |
| Chromium (Cr) | 15.0 | 17.0 |
| Nickel (Ni) | 1.50 | 3.00 |
| Nitrogen (N) | 0.15 | 0.30 |
| Copper (Cu) | - | 1.00 |
| Iron (Fe) | Balance | Balance |

Manganese in S20400 is 7.0 to 9.0 percent. Some published tables show manganese as 15.0 to 17.0 percent, which simply repeats the chromium range. Our mill certificates state the 7.0 to 9.0 percent range.

## Mechanical properties

Specified minimums, annealed, ASTM A666 for UNS S20400:

| Property | Imperial | Metric |
| --- | --- | --- |
| Tensile strength, min | 95 ksi | 655 MPa |
| Yield strength 0.2 percent, min | 48 ksi | 330 MPa |
| Elongation in 2 in., min | 35 % | 35 % |

Typical room temperature values:

| Property | Typical |
| --- | --- |
| Ultimate tensile strength | 110 ksi (758 MPa) |
| Yield strength, 0.2 percent offset | 55 ksi (379 MPa) |
| Elongation in 2 in. | 50 % |
| Hardness | 95 HRB |

ASTM A666 and ASTM A240 cover sheet, strip, plate and flat bar, not forgings, and there is no separate ASTM forging specification for S20400. We certify forgings to S20400 chemistry and agree the mechanical acceptance values, test location and test direction on the order.

## Forging and heat treatment

| Operation | Parameters |
| --- | --- |
| Melting | EAF plus VOD as standard, ESR on request |
| Forging | Heat to 1093 C (2000 F) and soak, raise to 1176 C (2150 F), equalise, then forge |
| Annealing | Soak at 1038 to 1121 C (1900 to 2050 F), then cool rapidly in water or air |
| Hardening | By cold work only, no response to heat treatment |
| Machining | Same methods and tooling as 300 series austenitic stainless, positive rake, slower speeds, sulphurised lubricant, chip breakers and curlers because chips are stringy and tough |

## Corrosion, wear and magnetic behaviour

Pitting resistance measured in 10 percent FeCl3 solution is better than Type 304. In sulfuric acid and hydrochloric acid the grade is much better than Types 409 and 410 and approaches Type 304 in more dilute solutions.

Corrosive wear resistance is high under a range of sliding conditions. Stainless steels as a class resist abrasion far better than AR steels once conditions are even mildly corrosive, and Nitronic 30 is more cost effective than Types 409 and 304 in wet abrasive duty.

Unlike the other nitrogen strengthened Nitronic grades, Nitronic 30 undergoes magnetic transformation when cold worked, because deformation martensite forms. That martensite raises strength, work hardening rate and abrasion resistance, but the grade should not be chosen where the part must stay non-magnetic after forming.

| Cold work, % | 0 | 10 | 20 | 30 | 40 |
| --- | --- | --- | --- | --- | --- |
| Ferrite number | 0 | 3 | 10 | 21 | 27 |

Nitronic 30 can be fusion welded with the arc processes normally used for austenitic stainless steels, with good ductility and toughness and resistance to weld cracking without preheat or postheat. A small amount of ferrite forms in autogenous welds, which holds down hot cracking sensitivity. Parameters follow the other Nitronic grades rather than standard austenitics, with slower travel speed and a hotter shielding gas for GTAW, argon plus 5 percent hydrogen or helium. Standard austenitic fillers or the AWS A5.9 and A5.4 Nitronic fillers 209, 240, 218 and 219 can be used. Matching weld wire is UNS S20980, AWS A5.9 Class ER209.

## Forged products in Nitronic 30

| Forged form | Service |
| --- | --- |
| Seamless rolled rings, forged rings | Magnetic ore separator screens, bulk solids handling equipment, wear rings |
| Round bars, shafts, spindles | Mechanical and structural parts needing high strength with wet abrasion resistance |
| Flanges, tube sheets, sleeves, bushings | Water supply and water control structures, sewage treatment plant equipment |
| Discs, blanks, gears, rolls | Coal buckets, hoppers, hopper cars, chutes and chute liners |
| Open-die blocks and custom forgings | Truck and bus frames, rapid transit structures, refrigerated truck rear frames, shipboard container structures, food processing equipment |

Tensilised Nitronic 30 has been used in rapid transit structures where a strength to weight ratio up to three times that of carbon steel improves operating efficiency. Other uses include hose clamps, safety belt anchors and fasteners. Sizes are made to drawing.

## Testing and certification

Ultrasonic testing is carried out to EN 10228-4, the part covering austenitic and austenitic-ferritic stainless steel forgings. EN 10228-3 applies to ferritic and martensitic forgings and does not apply to this grade. ASTM A388 and SEP 1921 can also be applied on request.

Certificates are issued to EN 10204 3.1, or EN 10204 3.2 with third party witness such as BV, SGS, TUV, LR or DNV. Chemical analysis, tensile, hardness, impact, grain size, PMI, liquid penetrant examination and a dimensional report are available.

## Questions we are asked about this grade

**What is Nitronic 30?**
Nitronic 30, designated UNS S20400, is a nitrogen and manganese strengthened austenitic stainless steel containing 15.0 to 17.0 percent chromium, 7.0 to 9.0 percent manganese, 1.5 to 3.0 percent nickel and 0.15 to 0.30 percent nitrogen.

**Is Nitronic 30 magnetic?**
In the annealed condition it is essentially non-magnetic, ferrite number 0. It becomes magnetic when cold worked, reaching ferrite number 3 at 10 percent cold work and 27 at 40 percent cold work.

**How does Nitronic 30 compare with Type 304?**
About 50 percent higher yield strength than Type 304L, better pitting resistance than Type 304 in 10 percent ferric chloride, at lower alloy cost because nickel is only 1.5 to 3.0 percent.

**What is the forging temperature for Nitronic 30?**
Soak at 1093 C (2000 F), raise to 1176 C (2150 F) and equalise, then forge. Anneal at 1038 to 1121 C (1900 to 2050 F) and cool rapidly in water or air.

**Which standards cover Nitronic 30?**
UNS S20400. Flat products: ASTM A240, ASTM A666, ASME SA240. Weld wire: UNS S20980, AWS A5.9 Class ER209. No dedicated ASTM forging specification exists for S20400.

**Can Nitronic 30 be used in seawater or subsea service?**
No. It has no molybdenum and only 1.5 to 3.0 percent nickel. Use A182 F51, F53, F55, F44, 904L or Alloy 31 instead.

**Who forges Nitronic 30 parts?**
Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. Telephone 0086-189-2135-9659, email sales@steelforgepieces.com.

## References

Composition, typical mechanical properties, corrosion behaviour, cold work ferrite data and weldability follow the Cleveland-Cliffs product data sheet for Nitronic 30 Stainless Steel and ASM International Alloy Digest SS-1138. Minimum mechanical requirements follow ASTM A666 for UNS S20400. Ultrasonic acceptance follows EN 10228-4.

NITRONIC is a registered trademark of Cleveland-Cliffs Inc., successor to AK Steel. Jiangyin Jiangnan Metal Co., Ltd. is an independent forging manufacturer and is not affiliated with, endorsed by or sponsored by the trademark owner.