Nickel 200 (UNS N02200) and 201 (UNS N02201) are dual-certifiable wrought nickel materials. They differ only in the maximum carbon levels present—0.15% for Nickel 200 and 0.02% for Nickel 201.
Nickel 200 plate is normally limited to service at temperatures below 600ºF (315ºC), since at higher temperatures it can suffer from graphitization which can severely compromise properties. At higher temperatures Nickel 201 plate should be utilized. Both grades are approved under ASME Boiler and Pressure Vessel Code Section VIII, Division 1. Nickel 200 plate is approved for service up to 600ºF (315ºC), while Nickel 201 plate is approved up to 1250ºF (677ºC).
Both grades offer outstanding corrosion resistance to caustic soda and other alkalis. The alloys perform best in reducing environments but can also be used under oxidizing conditions that produce a passive oxide film. They both resist corrosion by distilled, natural water and flowing seawater but are attacked by stagnant seawater.
Nickel 200 and 201 are ferromagnetic and exhibit highly ductile mechanical properties across a wide temperature range.
Both grades are easily welded and processed by standard shop fabrication practices.