Nickel 200 vs. Nickel 201: A Complete Guide to Choosing the Right Pure Nickel Alloy
When you need the corrosion resistance, conductivity, and formability of commercially pure nickel, two grades immediately come to mind: Nickel 200 and Nickel 201.
At first glance, they look nearly identical. Both contain at least 99% nickel, with only trace amounts of iron, silver, manganese, copper, carbon, and sulfur. But a small difference in carbon content leads to a major performance divide — especially when temperatures rise.
In this guide, we’ll break down:
What makes Nickel 200 and Nickel 201 different
Why carbon content matters above 315°C
How to choose the right grade for your application
Cost, availability, and industry standards
Let’s dive in.
The Core Difference: Carbon Content
The only significant chemical difference between Nickel 200 and Nickel 201 is carbon.
| Grade | Maximum Carbon Content |
|---|---|
| Nickel 200 | 0.15% |
| Nickel 201 | 0.02% |
That’s just 0.13% — but it changes everything at high temperatures.
Why Carbon Matters: The Embrittlement Problem
When exposed to temperatures above 315°C (600°F) , Nickel 200 can undergo a process called graphitization.
Here’s what happens:
Carbon precipitates at grain boundaries
Brittle graphite networks form
The material becomes weak and brittle (intergranular embrittlement)
Under stress, it can fail unexpectedly
Nickel 201, with its much lower carbon content (≤0.02%), resists graphitization and maintains its strength and ductility at higher temperatures.
Quick Temperature Guide
| Grade | Safe Service Temperature |
|---|---|
| Nickel 200 | Below 315°C (600°F) |
| Nickel 201 | Above 315°C (600°F) — up to 600°C in vessels |
Corrosion Resistance at Temperature
Both alloys offer excellent resistance to:
Caustic alkalies
Reducing chemicals
However, Nickel 201 is the preferred choice for high-temperature applications such as:
Sodium hydroxide evaporators operating up to 450°C
High-temperature chemical processing equipment
Components subject to thermal cycling above 315°C
Mechanical Properties: How They Compare
At room temperature, Nickel 200 and Nickel 201 behave similarly — but with a few important differences.
Tensile Strength & Hardness (Annealed Condition)
| Property | Nickel 200 | Nickel 201 |
|---|---|---|
| Tensile Strength (Ultimate) | 420 – 540 MPa | 390 – 660 MPa |
| Yield Strength (Proof) | 120 – 370 MPa | 80 – 510 MPa |
| Elongation at Break | 23 – 44% | 4.5 – 45% |
| Hardness (Brinell) | ~110 | ~110 |
| Elastic Modulus | 180 GPa | 180 GPa |
In the annealed condition specifically:
Nickel 200 shows slightly higher tensile strength (420 MPa vs. 400 MPa)
Nickel 200 also has higher yield strength (120 MPa vs. 93 MPa)
Both offer excellent ductility (~43-44% elongation when annealed)
Fatigue Strength — A Big Difference
This is where the two grades really separate:
| Grade | Fatigue Strength (Annealed) |
|---|---|
| Nickel 200 | ~230 MPa |
| Nickel 201 | ~78 MPa |
👉 Nickel 200 is the better choice for applications involving cyclic loading at room temperature.
How to Choose: Nickel 200 or Nickel 201?
Choose Nickel 200 When:
✅ Operating temperatures stay below 315°C (600°F)
✅ You need slightly higher room-temperature strength
✅ Fatigue resistance is a primary concern
✅ Cost optimization matters (generally less expensive)
✅ Standard alkaline electrolyzers (70-90°C operation)
Choose Nickel 201 When:
✅ Operating temperatures may exceed 315°C (600°F)
✅ Thermal cycling could approach the embrittlement threshold
✅ Long-term high-temperature stability is critical
✅ You need slightly better electrical/thermal conductivity
✅ Advanced high-temperature electrolysis systems
✅ Components near heat sources or in process upset scenarios
Cost and Availability
Material Cost
Both grades have similar base pricing. However, Nickel 201 typically carries a small premium (5-15%) due to tighter carbon control during production. For many engineers, this modest premium is well worth the broader temperature range.
Availability
Both Nickel 200 and Nickel 201 are widely available in:
Wire mesh (woven and expanded) — rolls or sheets
Foil and strip — for precision applications
Wire — diameters from 0.025mm to 21mm
Sheet and plate — thicknesses from 0.1mm to 10mm+
Custom fabricated components
Industry Standards
| Grade | Specifications |
|---|---|
| Nickel 200 | ASTM B160, ASTM B162, BS 3076 NA11, W.NR 2.4066 |
| Nickel 201 | ASTM B160, ASTM B162, BS 3076 NA12, W.NR 2.4061/2.4068 |
Final Thoughts
Choosing between Nickel 200 and Nickel 201 doesn’t have to be complicated.
Stay below 315°C? Nickel 200 is a cost-effective, high-fatigue-strength option.
Going above 315°C or facing thermal cycling? Nickel 201 is your only safe choice.
Both materials deliver excellent corrosion resistance, formability, and electrical performance. The decision comes down to temperature — and that 0.13% of carbon.
About ZYTC Alloy
ZYTC Alloy is a certified supplier of Nickel 200 and Nickel 201. We offer pure nickel alloys in bar, plate, wire, strip, and custom forms — backed by full traceability and mill test reports.
📧 Email: daisy@zytcsteel.com
📱 WhatsApp / WeChat: +86 17335753350
🌐 Website: www.zytcalloys.com
Contact us for product information, technical support, and competitive pricing.
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