Corrosion Resistant Alloys
NAS 64
- JISSUS 329J4L
- UNSS32506
- DIN/ENー
Duplex Stainless Steel
NAS 64 (SUS 329J4L, UNS S32506, ASME Code Case 2543) is an austenitic-ferritic stainless steel which was developed by Nippon Yakin, and provides excellent corrosion resistance against phosphoric acid, acetic acid, various sulfur compounds, etc. In particular, due to its high Cr and Mo composition, its local corrosion resistance is particularly improved in comparison with Type 316L. Nippon Yakin supplies this product in plate, sheet and strip form.
| Chemical Composition | 25Cr-6.5Ni-3.3Mo-0.17N |
|---|---|
| Product shape |
 Coil Sheet Plate |
| Workability | High temperature strength is similar to Type 430 in the range of 950~1150℃. However the steel shows rapid increase in the strength below 900℃. 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 the standard austenitic stainless steels, including shielded metal arc welding, TIG welding, and plasma welding. Same duplex grade type welding consumable should be used. |
| Heat Treatment | NAS 64 is not hardened by heat treatment. After heating to a solution treatment temperature of 1050~1080℃, quenching is necessary. Cooling must be performed as rapidly as possible so at to minimize the time when the material is exposed to the embrittlement temperature range (475℃ embrittlement, σ phase embrittlement). |
| Pickling | A mixture of nitric acid and fluoric acid is used in pickling. However, because descaling is somewhat difficult in comparison with Type 304, alkali immersion before acid pickling, and if possible, shot blasting are extremely effective. |
| Applications | Various types of pollution prevention equipment, Chemical and petrochemical plant, Pulp and paper plant, Equipment handling sea water, Water gate, etc. |