Corrosion Resistant Alloys
NAS 325N
- JISー
- UNSN08031
- DIN/ENー
NAS 325N (UNS N08031) is a stainless steel with extremely superior corrosion resistance and can be used in many severe corrosion environments. In addition to local corrosion resistance approaching that of nickel-base corrosion-resistant alloys, it also provides excellent acid resistance. Nippon Yakin supplies this product in plate, sheet and strip form.
| Chemical Composition | 27Cr-31Ni-6.5Mo-1.2Cu-0.2N |
|---|---|
| Product shape |
 Coil Sheet Plate |
| Workability | NAS 325N has cold and hot workability similar to that of standard austenitic stainless steels. However, the high strength of this material must be considered in both cold working and hot working. |
| Weldability | Welding can be performed by TIG, MIG, and shield metal arc welding in much the same manner as with standard austenitic stainless steels. Alloy 276 welding consumable should be used. |
| Machinability | As a feature of high Ni stainless steels, machining of NAS 325N is difficult in comparison with standard austenitic stainless steels, but it is easier than with nickelbased alloys. A 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 NAS 325N is normally performed at the temperature range from 1150 to 1180℃ 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 NAS 325N, 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, flue gas desulfurization equipment, papermaking plants, heat exchangers using seawater, offshore structures |