Manufacturer: Nippon Yakin Kogyo Co., Ltd
Model: NAS254N

NAS254N (UNS S32053)
High Corrosion Resistant Super Stainless Steel

NAS254N (SUS836L, UNS S32053) is a high corrosion resistance austenitic stainless steel with a high nickel, high chromium, high molybdenum alloy design, and provides excellent corrosion resistance in severe corrosion environments such as high temperature seawater. Depending on the environment, this stainless steel offers high economy combined with corrosion resistance comparable to that of Nickel alloy and pure titanium. Nippon Yakin supplies this product in plate, sheet, and strip form.

Chemical Composition	23Cr-25Ni-5.5Mo-0.2N
Product shape	Coil	Sheet	Plate
Workability	Hot and cold workability similar to standard austenitic stainless steels like Type 304, 316; requires care due to high strength
Weldability	Various methods applicable; shielded metal arc welding, TIG welding, and plasma welding suitable. Alloy 276 consumables recommended.
Machinability	Machining is difficult but easier than Ni-based alloys; use of ultra-hard tool and slow feed rate recommended
Heat Treatment	Solution annealing at 1080-1180°C, quenching in water or rapid cooling
Pickling	Mixture of nitric acid and hydrofluoric acid; material should be immersed in alkaline solution before pickling, shot blasting effective
Applications	Food manufacturing, Salt manufacturing, Pharmaceutical plants, Chemical plants, Marine structures, Heat exchangers

Steel Grade/Standard

Nippon Yakin Grade	JIS G 4304/4305	ASTM A240	EN
NAS254N	SUS836L	UNS S32053	—

Chemical Composition

Specification	C	Si	Mn	P	S	Ni	Cr	Mo	N
SUS836L	≤0.030	≤1.00	≤2.00	≤0.045	≤0.030	24.00 – 26.00	19.00 – 24.00	5.00 – 7.00	≤0.25
UNS S32053	≤0.030	≤1.00	≤1.00	≤0.030	≤0.010	24.00 – 26.00	22.00 – 24.00	5.00 – 6.00	0.17 – 0.22

Density [g/cm³]	8.06
Specific heat [J/kg·K]	457
Electrical resistivity [µΩ·cm]	94.7
Thermal conductivity [W/m·K]	11.9
Average coefficient of thermal expansion [10⁻⁶/°C]	30-100°C: 14.6 30-200°C: 15.2 30-300°C: 15.5 30-400°C: 15.8
Young’s modulus [MPa]	19.7 × 10⁴
Magnetism	None
Melting range [°C]	1330 – 1390

Mechanical Properties

Mechanical Properties at Room Temperature

Specification	0.2% proof stress [MPa]	Tensile strength [MPa]	Elongation [%]	Hardness [HBW]	Hardness [HRBW]	Hardness [HV]
SUS836L	≥275	≥640	≥40	≤217	≤96	≤230
UNS S32053	≥295	≥640	≥40	≤217	≤96	—
Cold-rolled sheet 2mm	385	760	46	—	—	—
Hot-rolled plate 16mm	336	725	56	172	—	—

NAS254N is a high Cr, high Mo stainless steel which provides excellent pitting corrosion resistance and crevice corrosion resistance in high Cl environments. As a high Ni steel, it also offers excellent stress corrosion cracking resistance.

Pitting Corrosion Resistance

Alloy	ASTM G48 Method A	ASTM G48 Method C
	22°C	50°C	Critical pitting corrosion temperature CPT (°C)
NAS255	○	×	50
NAS329J3L	○	×	50
NAS64	○	○	55
NAS254N	○	○	80

ASTM G48 Method A (○: No pitting corrosion, ×: Pitting corrosion)
Test solution: 6%FeCl₃
Test temperature: 22°C, 50°C (Recommended temperature in this test)
Test time: 72h

Crevice Corrosion Resistance

Alloy	ASTM G48 Method D
Critical crevice corrosion temperature CCT (°C)
NAS255	10
NAS329J3L	25
NAS64	30
NAS254N	45

* Test conditions: ASTM G48 Method D
* Test solution: 6%FeCl₃ + 1%HCl
* Test time: 72h

Stress Corrosion Cracking Resistance

Alloy	MgCl₂ concentration (boiling point °C are in brackets)
	45% (155°C)	42% (143°C)	40% (138°C)	38% (134°C)	35% (126°C)	30% (115°C)	25% (110°C)	20% (108°C)
NAS255	×	×	×	×	○	○	○	○
NAS329J3L	×	×	×	×	×	○	○	○
NAS64	×	×	○	○	○	○	○	○
NAS254N	○	○	○	○	○	○	○	○

 Test conditions: Immersion in boiling MgCl₂ solution
They use a U-bend test specimen.
○: No stress corrosion cracking
×: Stress corrosion cracking

Acid Resistance

Corrosion rate in sulfuric acid at 80°C (mm/y)

Alloy	5%	10%	20%	40%	60%	80%
NAS255	<0.01	<0.01	0.78	2.95	0.48	5.01
NAS329J3L	0.01	0.17	4.65	365.9	145.6	106.4
NAS64	<0.01	0.02	1.07	191.9	1054	60.72
NAS254N	0.02	0.05	1.02	2.11	2.16	7.76

Test time: 24h

Corrosion rate in hydrochloric acid at 80°C (mm/y)

Alloy	0.1%	1%	2%	3%
NAS255	<0.01	0.01	2.70	3.72
NAS329J3L	0.02	0.03	31.10	60.62
NAS64	0.01	0.12	12.94	30.51
NAS254N	0.01	0.02	0.01	9.14

Test time: 24h

Reference

Alloy	JIS	UNS No.	Chemical composition
NAS255	SUS890L	N08904	20Cr-24Ni-4.3Mo-1.5Cu
NAS329J3L	SUS329J3L	S32205	22Cr-5.3Ni-3.0Mo-0.16N
NAS64	SUS329J4L	S32605	25Cr-6.5Ni-3.3Mo-0.17N
NAS254N	SUS836L	S32053	23Cr-25Ni-5.5Mo-0.2N

Workability