Carbon (max ~0.02%)
Manganese (max ~0.35%)
Iron (max ~0.40%)
Copper (max ~0.25%)
Silicon (max ~0.10%)
These trace elements are carefully limited to preserve the material's key characteristics, such as ductility and corrosion resistance.
3.What are the properties of Ni201?
Ni201 (nickel 201) exhibits a combination of mechanical, chemical, and thermal properties that make it suitable for diverse industrial applications. Its key properties are summarized below:
Mechanical Properties (at Room Temperature, Annealed Condition)
Tensile Strength: 380–550 MPa
Yield Strength (0.2% Offset): 140–280 MPa
Elongation (in 50 mm): 40–55% (high ductility, enabling easy forming)
Hardness (Brinell): ~60–80 HB (soft and malleable, ideal for cold working)
Chemical/Corrosion Resistance
Excellent resistance to corrosion by neutral and alkaline solutions (e.g., sodium hydroxide, potassium hydroxide) at moderate temperatures.
Good resistance to organic acids (e.g., acetic acid, formic acid) and most non-oxidizing acids (e.g., hydrochloric acid) in the absence of aeration.
Limited resistance to oxidizing acids (e.g., nitric acid) and strong oxidizers, as these can cause surface passivation breakdown.
Resists corrosion in dry gases (e.g., hydrogen, nitrogen) but may tarnish slightly in moist, oxygen-rich environments (without significant material loss).
Thermal Properties
Melting Point: ~1455°C (similar to pure nickel, as alloying additions are minimal).
Thermal Conductivity: ~91 W/(m·K) at 20°C (higher than many nickel alloys, making it suitable for heat transfer applications).
Coefficient of Thermal Expansion: ~13.3 × 10⁻⁶/°C (20–100°C) – low enough to minimize thermal stress in temperature-cycling environments.
Electrical Properties
Electrical Resistivity: ~0.069 × 10⁻⁶ Ω·m at 20°C (lower than nickel 200, its close counterpart, due to lower carbon content). This makes it useful for electrical components like connectors and lead wires.
Other Key Characteristics
Low Carbon Content: Unlike nickel 200 (which has ~0.15% max carbon), Ni201 has ≤0.02% carbon, eliminating the risk of "graphitization" (carbon precipitation) at high temperatures (>315°C). This makes it stable for long-term use in elevated-temperature applications (e.g., furnace parts).
Weldability: Highly weldable using common methods (TIG, MIG, resistance welding) without significant cracking risk, thanks to its ductility and low impurity levels.
Magnetism: Ferromagnetic at room temperature (like pure nickel), but loses magnetism above its Curie temperature (~355°C).
