Nickel 200 is a commercially pure wrought nickel alloy (99.6 percent minimum nickel) with excellent mechanical properties and outstanding corrosion resistance, particularly in reducing environments and caustic alkalis. The alloy is magnetic, has good thermal and electrical conductivity, and exhibits good formability and weldability.

The nominal chemical composition is: nickel 99.6 percent minimum, carbon up to 0.15 percent, iron up to 0.40 percent, manganese up to 0.35 percent, silicon up to 0.35 percent, copper up to 0.25 percent, and sulfur up to 0.01 percent.

Key mechanical properties (typical, annealed condition):

● Tensile strength: 380–550 MPa

● Yield strength (0.2% offset): 100–300 MPa

● Elongation: 40–50 percent

● Hardness: 80–120 HV

● Density: 8.89 g/cm³

Nickel 200 offers excellent resistance to caustic alkalis (sodium and potassium hydroxide) across a wide temperature and concentration range. It also resists many reducing acids, neutral and alkaline salt solutions, and dry gases. However, it has poor resistance to oxidizing acids (e.g., nitric acid) and is not recommended for high-temperature sulfur-containing atmospheres. The alloy maintains good ductility from cryogenic temperatures up to about 315°C (600°F) for continuous service, though it can be used at higher temperatures for shorter durations.

Common standards: ASTM B162 (plate, sheet, strip), B160 (rod, bar, wire), B161 (seamless pipe and tube), B163 (seamless tube for heat exchangers), ASME SB-162, SB-160, SB-161, and QQ-N-281.

Typical applications include:

● Chemical processing: equipment handling caustic alkalis, such as evaporators, tanks, piping, and pump shafts.

● Electronics: leads, battery components, and electrical contacts.

● Food processing: equipment for handling fatty acids and other food products.

● Aerospace and military: various components requiring pure nickel properties.

● Manufacture of nickel salts and catalysts.

Comparison with Nickel 201: Nickel 201 is a low-carbon version (carbon max 0.02 percent) of Nickel 200, designed for use at elevated temperatures (above 315°C) where graphite precipitation could embrittle Nickel 200. For service below 315°C, Nickel 200 is preferred; above 315°C, Nickel 201 should be used.

Selection guidance: Choose Nickel 200 for applications requiring excellent corrosion resistance to caustic alkalis and reducing environments, combined with good mechanical properties and electrical conductivity, at temperatures below 315°C. For higher temperature service, select Nickel 201. For oxidizing acid environments, a nickel-chromium alloy such as Inconel 600 is more suitable.