Views: 23 Author: Monica Publish Time: 2025-10-15 Origin: Site
Nickel 201 (UNS N02201) is a low-carbon, commercially pure wrought nickel (Ni ≥ 99.0%, C ≤ 0.02%) supplied as plate, sheet, coil and strip under ASTM B162 / ASME SB-162. Its controlled low carbon prevents graphite precipitation and embrittlement above 316 °C (600 °F), which makes N02201 the preferred pure-nickel form for caustic soda equipment and elevated-temperature service where Nickel 200 (UNS N02200) would degrade.
ASTM B162 covers rolled commercially pure nickel N02200 and low-carbon nickel N02201 plate, sheet and strip; N02201 is the low-carbon variant selected for service above 316 °C (600 °F), while N02200 (Nickel 200) is used below that limit.
ASTM B162 (current active version B162-26, ASTM International) specifies chemical composition, tensile strength, yield strength, elongation, Rockwell hardness, dimensional tolerances, grain size for deep-drawing quality, and inspection methods for rolled nickel plate, sheet and strip. ASME SB-162 is the pressure-vessel adoption of the same specification. For sheet and strip, AMS 5553 covers N02201 only. The material is normally delivered annealed; cold-rolled tempers raise strength for springs and formed parts.
UNS N02201 contains at least 99.0% nickel with carbon capped at 0.02%; iron, manganese, silicon, sulfur and copper each carry a low maximum, which preserves purity, ductility and alkaline corrosion resistance.
Element | ASTM B162 / UNS N02201 limit (wt%) | Function in the alloy |
Ni | ≥ 99.0 (balance) | Base element; delivers alkaline and neutral corrosion resistance |
C | ≤ 0.02 | Low carbon prevents graphite precipitation above 316 °C |
Fe | ≤ 0.40 | Residual impurity kept low to protect purity |
Mn | ≤ 0.35 | Deoxidizer; minor strengthening |
Si | ≤ 0.35 | Deoxidizer; controls melt cleanliness |
S | ≤ 0.010 | Kept low to avoid hot cracking and brittleness |
Cu | ≤ 0.25 | Residual impurity |
Table 1. UNS N02201 composition limits per ASTM B162; magnesium, when specified as a deoxidant, falls in 0.02-0.10%.
N02201 has a density near 8.9 g/cm³, a melting range of 1433-1446 °C, high thermal and electrical conductivity compared with stainless steel, and is ferromagnetic with a Curie point near 357 °C.
Property | Value | Note / source |
Density | 8.88-8.90 g/cm³ | NYK 8.88; ATI 8.90 |
Melting range | 1433-1446 °C | Mill datasheets |
Thermal conductivity | 72.7 W/(m·K) (room temp); 67.1 at 100 °C; 56.3 at 316 °C | NYK room temp; ATI temperature series |
Coefficient of thermal expansion | 12.9 (25-100 °C); 13.6 (25-200 °C); 14.2 (25-300 °C) µm/(m·K) | NYK average ranges |
Elastic modulus | About 207 GPa | ATI at 21 °C |
Magnetic behavior | Ferromagnetic; Curie point about 357 °C (670 °F) | ATI TDS |
Specific heat | 456 J/(kg·K) (room temp) | NYK / ATI |
Electrical resistivity | About 8.5-9.2 µΩ·cm (room temp) | ATI / NYK |
Table 2. Typical physical properties; values are representative and vary by gage and condition.
In the annealed condition, ASTM B162 requires N02201 sheet/strip to reach a minimum tensile strength of 345 MPa (50 ksi), yield strength of 80 MPa (12 ksi), and elongation of at least 30% (thickness-dependent); cold rolling raises strength into half-hard, hard and spring tempers.
Property (annealed) | ASTM B162 minimum | Typical ATI 201 annealed |
Tensile strength | ≥ 345 MPa (50 ksi) | About 403 MPa (58.5 ksi) |
0.2% yield strength | ≥ 80 MPa (12 ksi) | About 103 MPa (15 ksi) |
Elongation in 50 mm / 2 in | ≥ 30% (40% per NYK UNS sheet spec for gages ≥ 2.7 mm) | About 50% |
Hardness (soft/annealed) | Typically 65-85 HB (supplier reference) | Cold-worked tempers are higher |
Table 3. Spec minimums are contractual; typical values come from mill datasheets and are not guaranteed minimums.
N02201 is supplied as cold-rolled strip and sheet in soft to spring tempers and as hot-rolled plate; custom width, length and slit coil are standard, and the purchase order should state gage, temper and finish explicitly.
Category | Common options |
Form | Plate, sheet, coil, slit strip, foil, flat sheet |
Thickness | Strip/sheet 0.1-6 mm typical; plate up to about 100 mm |
Width / length | Width up to 2500 mm; length cut to requirement; slit coil on request |
Temper | Soft/annealed, quarter hard, half hard, hard, spring hard |
Surface finish | 2B, 2D, bright annealed (BA), matte/satin; PVC-protected on request |
N02201 resists boiling sodium hydroxide and neutral to reducing media and is virtually immune to chloride stress corrosion cracking; it is not suited to oxidizing mineral acids or sulfurous atmospheres above 316 °C.
In mill tests, NAS Ni201 corroded at under 0.01 mm/year in 20% boiling NaOH, about 0.02 mm/year in 40%, and about 0.03 mm/year in 60%, far below stainless steel 304. Nickel is not susceptible to caustic stress corrosion cracking. Limits matter: oxidizing mineral acids, oxidizing salts, and sulfurous atmospheres above 316 °C are corrosive, and high-chlorate diaphragm-cell liquor may require a chromium-bearing alloy instead.
Yes; TIG, MIG, shielded metal arc and resistance welding all work, and neither preheat nor post-weld heat treatment is generally required. Use a low-carbon ENi-1 (Nickel 141) filler and clean the joint of oils, paints and markings before welding.
N02201 welds resemble austenitic stainless procedures, but the molten weld metal is sluggish and penetration is lower because of high thermal conductivity, so joint gaps must stay open for filler access. Choosing a low-carbon, stabilized filler avoids introducing free carbon that could embrittle N02201 at elevated temperature. After severe cold forming, an intermediate anneal at roughly 760-1050 °C followed by water quench or rapid cooling restores softness.
Choose Nickel 201 (N02201) whenever continuous or intermittent service exceeds 316 °C (600 °F); below that limit, Nickel 200 (N02200) is usually the economical choice.
Aspect | Nickel 201 (UNS N02201) | Nickel 200 (UNS N02200) |
Carbon max | 0.02% | 0.15% |
Long-term 427-649 °C exposure | Resists graphitization; preferred above 316 °C | Carbon phase precipitates; ductility loss; not recommended above 316 °C |
Annealed strength | Slightly lower; very ductile | Slightly higher at room temperature |
Typical use | Caustic soda equipment, elevated-temp parts, battery tabs, electronics | Food processing, electrical parts, process water, service below 316 °C |
Table 4. The deciding factor is maximum operating temperature; near 427 °C, creep must be evaluated as a design criterion.
· Caustic soda production equipment: evaporators, cell liners and handling parts in low-chlorate alkali liquor.
· Battery tabs, current collectors and stamped battery components.
· Electronic terminals, lead frames and mobile-device contacts.
· Automotive electrical and electronic parts requiring conductivity and corrosion resistance.
· Food processing equipment and neutral process-water handling.
· Heat exchanger and conductive components where stainless steel lacks alkali resistance.
State the product form, thickness, width and length, temper, surface finish, and standard (ASTM B162 / ASME SB-162). Request an EN 10204 3.1 mill certificate and, for critical projects, a third-party inspection report. Nickel 201 price per kg follows the LME nickel price plus conversion and processing, so request a current quotation rather than relying on a fixed posted number.
What UNS number is Nickel 201 sheet?
Nickel 201 sheet, coil and strip carry UNS N02201 and are supplied under ASTM B162 / ASME SB-162.
What is the carbon limit of ASTM B162 N02201?
Maximum 0.02% carbon, compared with 0.15% maximum for Nickel 200 N02200.
Is Nickel 201 magnetic?
Yes. N02201 is ferromagnetic with a Curie point near 357 °C (670 °F).
Does Nickel 201 sheet need annealing after forming?
Not after mild forming; severe cold forming calls for an intermediate anneal at roughly 760-1050 °C followed by water quench or rapid cooling.
Can N02201 replace N02200 above 316 °C?
Yes, N02201 is the elevated-temperature choice; near 427 °C, creep must be evaluated by the designer.
What does Nickel 201 sheet cost per kg?
Price tracks the LME nickel price plus conversion; ask the supplier for a current, dated quotation.
[1] ASTM B162-26, Standard Specification for Nickel Plate, Sheet, and Strip, ASTM International (active, last updated 2026-02-12): https://store.astm.org/standards/b162
[2] ATI 200/201 Nickel Alloy Technical Data Sheet (UNS N02200 / N02201), Allegheny Technologies: https://www.atimaterials.com/Products/Documents/datasheets/nickel-cobalt/nickel-based/ati_200_201_tds_en1_v1.pdf
[3] Nippon Yakin Kogyo, NAS Ni201 (UNS N02201) product technical data: https://www.nyk.co.jp/en/pdf/products/NAS_Ni201_E.pdf
Disclaimer: This guide provides general technical information and does not replace the purchase specification, design code, mill certificate or authorized inspection authority. Verify all limits against the current ASTM B162 edition and the supplier certificate for each batch.
