Material Family

Low-Carbon Commercially Pure Nickel (Unalloyed)

The pure nickel alloy bar optimized for high-temperature stability.

Primary Distinction

Guaranteed Low Carbon Content (C ≤ 0.02 wt.%)

This is the sole but critical difference from Nickel 200, preventing graphite precipitation at grain boundaries during prolonged high-temperature service.

Common Forms (Bar)

Hot Rolled, Forged, or Cold Drawn Rounds, Hexagons, Squares. Also as Forging Billet.

Available in a wide range of diameters for machining and forging high-temperature components.

Chemical Composition (Typical wt.%)

Ni (+Co): ≥ 99.0
C: ≤ 0.02
Fe: ≤ 0.40
Mn: ≤ 0.35
Cu: ≤ 0.25
Si: ≤ 0.35
S: ≤ 0.01

The very low carbon level ensures long-term microstructural stability under thermal stress.

Mechanical Properties (Annealed, Room Temp)

Tensile Strength (Rm): 380 - 550 MPa
Yield Strength (Rp0.2): 100 - 275 MPa
Elongation (A): 40 - 55%

Identical ductility and formability to Nickel 200 bar. Lower strength than alloyed nickels but excellent for fabrication.

Physical Properties

Density: 8.89 g/cm³
Melting Point: 1435-1445 °C
Thermal Conductivity: 70 W/m·K (at 100°C)
Recommended Service Range: Cryogenic to ~650°C (1200°F) for continuous service.

Maintains excellent thermal and electrical conductivity. The safe upper temperature limit is significantly higher than for Nickel 200.

Key Corrosion Resistance

• Excellent resistance to hot, concentrated caustic alkalis (NaOH, KOH) – its premier application.

• Excellent resistance to neutral and reducing salts, organic acids, and dry halogen gases.

• Good resistance to dilute hydrochloric and sulfuric acids at room temperature.

• Poor resistance to oxidizing acids (e.g., nitric acid) and ammonium salts.

Corrosion resistance is identical to Nickel 200. Its advantage is sustained integrity in hot corrosive environments.

High-Temperature Stability

Resists the formation of intergranular graphite (embrittlement) caused by the decomposition of carbides (Ni₃C) when held in or slowly cooled through the 315°C-650°C range.

This stability is mandatory for equipment like high-temperature caustic evaporators, heaters, and heat exchangers.

Key Standards (Bar)

ASTM B160 / ASME SB-160 (Standard Specification for Nickel Rod and Bar - Grade UNS N02201)

The same ASTM standard covers both 200 and 201; the UNS number (N02201) defines the purchase.

Machinability

Machinability Rating: ~50%. Identical to Nickel 200. One of the more machinable nickel alloys. Requires sharp tools and positive rakes to manage its gummy nature.

Excellent for producing complex machined components for high-temperature service.

Typical Bar Applications

• High-Temperature Chemical Processing: Shafts, valves, fasteners, and support components for caustic evaporators and melters operating above 315°C (600°F).
• Electronics & Aerospace: High-temperature, high-purity structural components, heat sink bars.
• Synthetic Fiber Production: Godet rollers, spinnerets, and other high-temperature process machinery parts.
• Alkaline Fuel Cell & Electrolysis Systems: Current collectors, bipolar plates.
• Food & Pharmaceutical: High-temperature processing equipment requiring purity.

The specialist bar material for high-temperature, corrosive alkaline service and high-purity thermal applications.