The core difference between Alloy 200 (UNS N02200) and Alloy 201 (UNS N02201) lies in their carbon content, which directly determines their high-temperature performance. HT PIPE is a Alloy 200 (UNS N02200) and Alloy 201 (UNS N02201) supplier with 15+ export experience. Contact us for more information and quotes for free!
Alloy 200 Alloy 201 Corrosion Resistance
Common Advantages: Both exhibit excellent corrosion resistance in reducing environments, neutral, and alkaline media. They are particularly resistant to caustic soda, making them ideal for handling media such as sodium hydroxide at all concentrations and temperatures. They also exhibit good resistance to freshwater, seawater, dry halogen gases, and many organic compounds.
UNS N02200 and UNS N02201 chemical composition
| Grade | C≤ | Mn≤ | Si≤ | S≤ | Cu≤ | Fe≤ | Ni(min) |
| Ni200 | 0.15 | 0.35 | 0.35 | 0.01 | 0.25 | 0.40 | 99.0 |
| Ni201 | 0.02 | 0.35 | 0.35 | 0.01 | 0.25 | 0.40 | 99.0 |
UNS N02200 and UNS N02201 Mechanical and Physical Properties
Mechanical Properties: In the annealed state, both exhibit strength similar to that of mild steel and possess excellent ductility and toughness, making them easily adaptable to hot and cold working.
Physical Properties: They share similar physical properties, including density, magnetic properties, and thermal conductivity. Both are paramagnetic materials, maintain good toughness even at low temperatures, and possess high thermal and electrical conductivity.
| Mechanical properties | Tensile, min, ksi[MPa] | Yield, min, ksi[MPa] | Elongation, %(min) |
| Ni200 | 55[380] | 15[105] | 40 |
| Ni201 | 50[345] | 10[70] | 40 |
Alloy 200 and UNS N02201 Processing and Welding
Processing Properties: Both are easily adaptable to cold working, such as stamping, drawing, and spinning. It's important to note that they have a rapid work hardening rate, and intermediate annealing may be required during cold working to restore plasticity.
Weldability: Alloy 201 welds better than Alloy 200 due to its low carbon content, and the weld area resists intergranular corrosion better after welding. TIG or MIG welding, along with compatible consumables, is recommended.
How to Choose?
If your equipment operates below 315°C for extended periods and there's no risk of intergranular corrosion from post-weld heat treatment or extended high-temperature service, Alloy 200 is an economical and reliable choice.
Once operating temperatures exceed 315°C, or if the equipment involves welded structures subjected to stress in a corrosive environment, or if there are stringent requirements for material stability at extended high temperatures, then paying the slightly higher price for Alloy 201 is a critical investment to ensure long-term, safe operation.
