Corrosion Resistant Alloys

NAS 625

  • JISNCF 625
  • UNSN06625
  • DIN/EN
, comparable to Inconel® 625 Alloy

NAS 625 (NCF 625, UNS N06625) is a nickel-chromium-molybdenum alloy with an additional of niobium. Matrix stiffening provided by molybdenum and niobium results in high strength. The alloy resists a wide range of severe corrosion environments. It also offers resistance to high temperatures. Uses include parts in chemical and garbage incinerator plants. Nippon Yakin supplies this product in plate, sheet, and strip forms.

* Inconel is a registered trademark of Special Metals Corporation.

Products & Materials

NAS 625ProductsPDF(561KB)

Chemical Composition 62Ni-22Cr-9Mo-3.7Nb-0.2Ti-0.2Al
Product shape
Workability Because the high-temperature strength of NAS 625 is extremely higher than that of Type 304, care is required when hot working. The cold workability of NAS 625 is basically the same as that of standard austenitic stainless steels such as Type 304, Type 316, etc. However, the fact that this is a high strength material must be considered in cold 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. Susceptibility of NAS 625 to solidification cracking is higher than that of Type 304.
Heat Treatment Annealing of NAS 625 is normally performed at 871℃ and higher followed by being quenched in water or rapidly cooled by other means.
Solution annealing of NAS 625 is normally performed at 1093℃ and higher followed by being quenched in water or rapidly cooled by other means.
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 Chemical plants, nuclear power, seawater applications, jet engine parts, aircraft material, heat treatment furnace material, evaporators