UNS Number N02200/N02201
Nickel 200 and Nickel 201 are solid solution strengthened, commercially pure wrought materials with good mechanical properties over a wide range of temperatures and excellent resistance to many corrosives, in particular hydroxides. Nickel 201 was a modification of 200 to control carbon (.02 max) which keeps it from being embrittled by intergranular precipitates at temperatures of 600째 F to 1400째 F in many processes. Typically, the elemental restrictions of both, nickel 200 and nickel 201, are combined into one, dual-certified chemistry resulting in a single alloy with the desired characteristics of both alloys, Nickel 200/201.
In what forms is Nickel 200/201 available?
• Pipe & Tube (welded & seamless)
• Fittings (i.e. flanges, slip-ons, blinds, weld-necks, lapjoints, long welding necks, socket welds, elbows, tees, stub-ends, returns, caps, crosses, reducers, and pipe nipples)
What are the characteristics of Nickel 200/201?
• Highly resistant to various reducing chemicals
• Excellent resistance to caustic alkalies
• High electrical conductivity
• Excellent corrosion resistance to distilled and natural waters
• Resistance to neutral and alkaline salt solutions
• Excellent resistance to dry fluorine
• Widely used to handle caustic soda
• Good thermal, electrical and magnetostrictive properties
• Offers some resistance to hydrochloric and sulfuric acids at modest temperatures and concentrations
Both Nickel 200 and 201 offer corrosion resistance in reducing and neutral media as well as in oxidizing atmospheres provided that the oxidizing media allows the formation of a passive oxide film. This oxide film accounts for the materials excellent resistance in caustic environments. Corrosion rates in both marine and rural atmospheres are very low. The resistance of Nickel 200/201 to corrosion by distilled and natural waters is excellent. Plus it also gives excellent service in flowing sea water even at high velocity, but in stagnant or very low-velocity sea water severe local attack may occur under fouling organisms or other deposits. In hot water systems where the steam contains carbon dioxide and air in certain proportions, corrosion rates will be initially high but will decrease with time if conditions favor the formation of a protective film.
Nickel 200 is normally limited to service at temperatures below 600° F. At higher temperatures Nickel 200 products can suffer from graphitization which can result in severely compromised properties. When operating temperatures are expected to exceed 600° F, carbon content becomes critical. The lower carbon content of Nickel 201 makes the material resistant to graphitization and therefore less subject to embrittlement. Nickel 200 & 201 are approved for construction of pressure vessels and components under ASME Boiler and Pressure Vessel Code Section VIII, Division 1. Nickel 200 is approved for service up to 600° F while Nickel 201 is approved for service up to 1230° F. Melting point is 2615-2635° F.
Nickel 200 (UNS N02200) Chemical Composition, %
Nickel 201 (UNS N02201) Chemical Composition, %
In what applications is Nickel 200/201 used?
• Food processing equipment
• Marine and offshore engineering
• Salt production
• Caustic handling equipment
• Manufacture and handling of sodium hydroxide, particularly at temperatures above 300° F
• Reactors and vessels in which fluorine is generated and reacted with hydrocarbons
Applications where Nickel 200-201 can be used include chemical processing and storage, synthetic fiber production, and processes where sodium hydroxide and fluorine is used. Other applications include aerospace and defense as well as food processing. Nickel 200/201 has exceptional resistance to caustic alkalies at various temperatures and concentrations.
Fabrication with Nickel 200/201
All hot working and cold working practices can be utilized when shaping Nickel 200/201. Hot working temperatures should be between 1200° F and 2250° F with heavy forming to be performed at temperatures above 1600° F. Annealing should be performed at a temperature between 1300° F and 1600° F. Care should be taken when choosing the anneal temperature and time at temperature for this can greatly influence the mechanical properties and structure of the material.
Nickel 200/201 can be easily welded by conventional welding, brazing, and soldering processes with the exception of the oxyacetylene process.
Nickel 200/201 ASTM Specifications
Room Temperature properties of Various Products
||.2% Yield (ksi)
|Rod & Bar
|Rod & Bar
||Cold Drawn/Annealed or Hot-Finished/Annealed
|Tube & Pipe