Manufacturer: Nippon Yakin Kogyo Co., Ltd
Model:NAS354N

NAS354N (UNS N08354) High Corrosion Resistant Super Stainless Steel

NAS354N (NCF354, UNS N08354, ASME Code Case 2585-1) is a super austenitic stainless steel with excellent corrosion resistance in various environments. The high chromium, molybdenum, and nitrogen contents provide high resistance to crevice and pitting corrosion in oxidizing chloride environments while the high nickel content enhances resistance to stress corrosion cracking. The corrosion resistance of NAS354N exceeds the conventional 6 Mo super austenitic stainless steels because of containing 7.5% Mo. Nippon Yakin supplies this product in plate , sheet, and strip form.

Chemical Composition	23Cr-35Ni-7.5Mo-0.2N
Product shape	Coil	Sheet	Plate
Workability	The hot and cold workability of NAS354N is basically the same as that of standard austenitic stainless steels such as Type 304, Type 316. However, you must consider the high strength of this material in both cold and hot working.
Weldability	Various welding methods are applicable in the same manner as with the standard austenitic stainless steels, including shielded metal arc welding, TIG welding, and plasma welding. You should use Alloy 276 welding consumable.
Machinability	As a feature of high Ni stainless steels, although machining is difficult in comparison with the standard austenitic stainless steels, it is easier than with Ni-based alloys. An ultrahard tool should be used in machining if at all possible. It is also advisable to use a slower feed rate and deeper cutting depth.
Heat Treatment	Solution annealing of NAS354N is normally performed at the temperature range from 1125 to 1175°C followed by being quenched in water or rapidly cooled by other means.
Pickling	A mixture of nitric acid and hydrofluoric acid is used in pickling. However, due to the high corrosion resistance of NAS354N, scale is somewhat difficult to remove in comparison with Type 304. Therefore, the material should be immersed in an alkaline solution before pickling, or if possible, shot blasting is extremely effective.
Applications	Chemical plants, Food manufacturing plants, Salt manufacturing plants, Heat exchangers, Marine structures, Environment-related equipment.

Steel Grade/Standard

Nippon Yakin Grade	JIS G 4902	ASTM B625	EN
NAS354N	NCF354	UNS N08354	—

Chemical Composition

Specification	C	Si	Mn	P	S	Ni	Cr	Mo	N
NCF354	≦0.030	≦1.00	≦1.00	≦0.030	≦0.010	34.00 – 36.00	22.00 – 24.00	7.00 – 8.00	0.17 – 0.24
UNS N08354	≦0.030	≦1.00	≦1.00	≦0.030	≦0.010	34.00 – 36.00	22.00 – 24.00	7.00 – 8.00	0.17 – 0.24

Physical Properties

Density [g/cm³]	8.16
Specific heat [J/kg·K]	454
Electrical resistivity [µΩ·cm]	105.6
Thermal conductivity [W/m·K]	11.3
Average coefficient of thermal expansion [10⁻⁶/°C]	30 – 100°C: 14.0 30 – 200°C: 14.4 30 – 300°C: 14.7 30 – 400°C: 15.1
Young’s modulus [MPa]	19.4 × 10⁴
Magnetism	None
Melting range [°C]	1362 – 1391

Mechanical Properties

Mechanical Properties at Room Temperature

Specification	0.2% proof stress [MPa]	Tensile strength [MPa]	Elongation [%]	Hardness [HV]	Hardness [HRBW]
Specification (NCF354)	≥295	≥640	≥40	—	—
Specification (UNS N08354)	≥295	≥640	≥40	—	—
Example: Cold-rolled sheet 2mm	393	795	52	188	89

NAS354N 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)
NAS329J3L	○	×	50
NAS64	○	○	55
NAS185N	○	○	70
NAS254N	○	○	80
NAS354N	○	○	103

ASTM G48 Method A (○: No pitting corrosion, ×: Pitting corrosion)
Test solution: 6%FeCl ₃
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)
NAS329J3L	25
NAS64	30
NAS185N	40
NAS254N	45
NAS354N	60

Test conditions: ASTM G48 Method D
Test solution: 6%FeCl ₃ + 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)
NAS329J3L	×	×	×	×	×	○	○	○
NAS64	×	×	×	○	○	○	○	○
NAS185N	×	×	×	○	○	○	○	○
NAS254N	×	×	○	○	○	○	○
NAS354N	×	×	×	○	○	○	○	○

 

Test conditions: Immersion in boiling MgCl₂ solution
Test time: 300h
U-bend test specimen is used.
○: No stress corrosion cracking ×: Stress corrosion cracking

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

Alloy	5%	10%	20%	40%	60%	80%
NAS329J3L	0.01	0.17	4.65	365.9	1456	106.4
NAS64	<0.01	0.02	1.07	191.9	1054	60.72
NAS185N	0.04	1.32	2.89	3.20	4.78	—
NAS254N	0.05	1.02	2.11	2.16	7.76	—
NAS354N	0.01	0.03	0.23	0.06	3.02	4.99

Test time: 24h

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

Alloy	0.1%	1%	2%	3%
NAS329J3L	0.02	0.03	31.10	60.62
NAS64	0.01	0.12	12.94	30.51
NAS185N	0.01	0.02	4.20	7.21
NAS254N	0.01	0.02	0.01	9.14
NAS354N	0.02	0.03	0.02	7.35

Test time: 24h

Alloy	JIS	UNS No.	Chemical composition
NAS329J3L	SUS329J3L	S32205	22Cr-5.3Ni-3.2Mo-0.16N
NAS64	SUS329J4L	S32506	25Cr-6.5Ni-3.3Mo-0.17N
NAS185N	SUS312L	S31254	20Cr-18Ni-6Mo-0.8Cu-0.2N
NAS254N	SUS836L	S32053	23Cr-25Ni-5.5Mo-0.2N
NAS354N	NCF354	N08354	23Cr-35Ni-7.5Mo-0.2N