Nickel 200

Identity and selection

Special Metals normally limits Nickel 200 to below 600°F (about 315°C) because graphitization can impair properties above that range. It recommends low-carbon Nickel 201 (UNS N02201) for higher temperatures. Confirm product condition, environment, load and time in service separately. Special Metals Nickel 200 and 201 guidance

Nickel 200 is commercially pure wrought nickel, designated UNS N02200. It is distinct from nickel-chromium corrosion alloys and precipitation-hardened superalloys. Special Metals lists Werkstoff numbers 2.4060 and 2.4066 and a limiting composition of at least 99.0% nickel plus cobalt, with carbon at most 0.15% by mass. These are composition limits, not a promise that every delivered heat has the same chemistry. Special Metals, Nickel 200 & 201, SMC-061, September 2006

Producer offerings can be narrower. VDM's product finder lists Nickel 200 as Ni99.2 and describes material with differing nickel contents, 99.2 or 99.6 weight-%. It lists sheet/plate, strip, rod/bar, billet and wire. A requested purity level therefore belongs in the purchase specification, alongside the grade; the general name alone does not establish a particular producer variant or available size. VDM, complete product range, Nickel 200 entry

Specification, form and condition

ASTM B162-26 covers nickel plate, sheet and strip, including UNS N02200 and N02201. Its scope does not turn a plate certificate into a qualification for rod, tubing or a completed pressure component. Specify the applicable product standard and edition, dimensions, condition and required certification for the item being purchased. ASTM B162-26, official scope

Keep three kinds of information separate in a material record:

• Grade limits: chemical and mechanical requirements of the ordered specification.
• Producer reference data: values for the stated condition, form and test temperature.
• Delivered results: heat analysis, mechanical test results and traceability on the inspection document.

Bounded mechanical-property example

VDM's March 2022 data sheet, revision 02, gives the following short-term properties for soft-annealed Nickel 200 at 20°C, under its table 4a reference to DIN 17750. Its introductory qualification limits the mechanical data to specified semi-finished forms and dimensions; larger dimensions require separate agreement. VDM, Nickel 200/201, tables 4a–4c

These figures describe that annealed reference condition. They are not allowable stresses, fatigue strengths or values for a cold-worked finished part. For a purely illustrative calculation, a uniform 100 mm² section under 5,000 N has nominal stress 5,000 / 100 = 50 MPa. Its ratio to the tabulated proof strength is 50 / 100 = 0.50. This arithmetic omits stress concentrations, joint efficiency, corrosion loss, cyclic loading and design-code factors; it does not qualify a component.

Nickel 200 versus Nickel 201

Nickel 201 is a separate low-carbon grade, UNS N02201. Special Metals limits its carbon to 0.02%. The same bulletin normally restricts Nickel 200 to service below 600°F, approximately 315°C: graphitization at higher temperature can impair its properties, and it recommends Nickel 201 above that range. This is a material-selection warning, not a universal service-temperature rating or current pressure-code approval. Special Metals, Nickel 200 temperature limitation and Nickel 201 composition

Record transient metal temperatures and dwell as well as the steady operating condition.

Corrosion and process-fluid boundaries

The Nickel Institute's caustic-soda guide identifies commercially pure Nickel 200/201 as highly resistant to caustic itself, while warning that chromium-free nickel alloys are attacked by chlorate or hypochlorite contaminants. It also discusses mercury-related cracking and recommends low-carbon Nickel 201 above 300°C in this service to avoid graphite-related deterioration. Thus clean-caustic experience cannot establish suitability for an oxidizing, contaminated process stream. Nickel Institute, publication 10019, commercially pure nickel and chromium-free alloy sections

For selection, document concentration, impurities, temperature excursions, liquid/vapor location, flow and the acceptable corrosion rate. Include cleaning fluids and startup/shutdown chemistry, not only normal operation. Where published experience does not match the process, seek a supplier assessment or representative testing rather than assigning a generic “chemical resistant” label. Keep test conditions with any corrosion-rate entry so another reader can judge its applicability.

Fabrication and acceptance

VDM recommends soft-annealed stock for cold forming, with intermediate annealing where heavy deformation requires it. Its machining guidance addresses work hardening by maintaining tool engagement and cutting beneath the previously hardened layer. Heat-treatment cleanliness is important: sulfur, phosphorus, lead and other low-melting contaminants can damage material. Welding guidance calls for segregated, clean work areas and particularly effective shielding because pure nickel is susceptible to porosity. These are process considerations, not a complete machining or welding procedure. VDM, fabrication and welding sections, March 2022

Before releasing a part, retain the material certificate, final condition, relevant heat-treatment and joining records, dimensional acceptance criteria and service assumptions. Qualify the joint and inspect the finished condition required by the drawing or construction specification. Record deviations explicitly; do not silently substitute Nickel 201, another purity variant or cold-worked stock because its trade description sounds similar.

Source applicability

The Special Metals bulletin is printed September 2006; VDM's sheet is printed March 2022, revision 02. They provide producer guidance rather than certification of a particular shipment. The Nickel Institute guide is identified here by publication number; its URL contains a revision-year label, but no printed revision date was verified. Check contract-required editions separately.

See also grades, tempers and conditions.