Manufacturer: Nippon Yakin Kogyo Co., Ltd
Model: NAS329J3L

NAS 329J3L (UNS S32205, S31803)
NAS High Corrosion Resistant Duplex Stainless Steel

NAS 329J3L (SUS 329J3L, UNS S32205, S31803) is an Austenitic-ferritic stainless steel, which has superior corrosion resistance and high strength This steel provides better localized corrosion resistance than Type 316L and 317L, and industries such as chemical plants, seawater desalination plants, and seawater pumps apply it widely. Nippon Yakin supplies this product in plate, sheet, and strip form.

Chemical Composition	22Cr-5.3Ni-3.2Mo-0.1N
Product Shape	Coil	Sheet	Plate
Workability	High temperature strength is similar to Type 430 in the range of 950-1150°C. However, the steel shows a rapid increase in strength below 900°C. Cold working requires care because the higher proof stress and lower elongation of this steel, compared to Type 304, make the process more challenging.
Weldability	You can apply various welding methods, such as shielded metal arc welding, TIG welding, and plasma welding, in the same way as with standard austenitic stainless steels. It is recommended to use welding electrodes for UNS S32205. Preheating and post-heating are not necessary. The interpass temperature should not exceed 100°C to prevent formation of intermetallic compounds.
Heat Treatment	Solution annealing of NAS329J3L should be performed at 1040°C and higher followed by being quenched in water or rapidly cooled by other means. (Conditions provided in ASTM A480/A480M)
Pickling	You should use a mixture of nitric acid and hydrofluoric acid for pickling. Since descaling is more difficult compared to Type 304, it is recommended to perform alkaline immersion before pickling or to use shot blasting.
Applications	Chemical Plant, Chemical Tanker, Seawater desalination plant, Seawater pump, Thermal power plant flue gas desulfurization plants, Pulp and paper plants, Bridge.

Steel Grade/Standard

Chemical Composition

Physical Properties

Microstructure

A cross sectional microstructure of 16mm thick plate

Mechanical Properties

Mechanical Properties at Room Temperature

Corrosion Resistance

Pitting Corrosion Resistance

Test conditions

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

ASTM G48 Method C

• Test solution: 6% FeCl₃ + 1% HCl
  Test time: 72h

Crevice Corrosion Resistance

Test solution: 6% FeCl₃ + 1% HCl
Test time: 72h

Stress Corrosion Cracking Resistance

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

Acid Resistance

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

Test time: 24h

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

Test time: 24h

Workability

High temperature strength is similar to Type 430 in the range of 950-1150°C. However, the steel shows a rapid increase in strength below 900°C. Regarding cold workability, care is required as proof stress is high and elongation is low in comparison with Type 304.

Weldability

Various welding methods are applicable in the same manner as with standard austenitic stainless steels, including shielded metal arc welding, TIG welding, and plasma welding. The use of welding electrodes for UNS S32205 is recommended. Preheating and post-heating are not necessary. The interpass temperature should be no more than 100°C to prevent the formation of intermetallic compounds.

Heat Treatment

Solution annealing of NAS 329J3L should be performed at 1040°C and higher followed by being quenched in water or rapidly cooled by other means. (Conditions provided in ASTM A480/A480M)

Pickling

A mixture of nitric acid and fluoridic acid is used in pickling. Descaling is somewhat difficult in comparison with Type 304, so alkaline immersion before pickling, or shot blasting, is recommended.

Applications

• Chemical Plant, Chemical Tanker
• Seawater desalination plant, Seawater pump
• Thermal power plant flue gas desulfurization plants
• Pulp and paper plants
• Bridge

Certification

It is possible to manufacture UNS S32205/S31803 in accordance with the NORSOK standard. The thickness is up to 50mm.

• NORSOK M-650
• NORSOK M-630 MDS D45