Nickel alloy forgings · Werkstoff 2.4066

2.4066 / Ni 99.2 / Nickel 200 / UNS N02200 Forging Parts

Published: 12 May 2022 · Last updated: 8 August 2026 · Technically reviewed by the Jiangyin Jiangnan Metal Co., Ltd. Metallurgical Engineering Team · Reading time ≈ 18 min

9 Exclusive 2.4066 Engineering Tools

These calculators are built specifically for commercially pure nickel and are not available on any other 2.4066 page. They encode the three decisions that actually go wrong on Nickel 200 orders: the 200-vs-201 temperature split, the sulfur-free forging requirement, and the caustic concentration limit.

What Is 2.4066 (Ni 99.2 / Nickel 200)?

2.4066 is the European material number (Werkstoff-Nummer) for Ni 99.2 — commercially pure wrought nickel. It is not an alloy in the usual sense: it is nickel with a minimum of 99 % purity, where the remaining fraction is residual carbon, iron, manganese, silicon, copper and sulfur, each held to a fraction of a percent. Internationally the same material is sold as Nickel 200, Alloy 200 or UNS N02200. The number 2.4060 also appears in older European literature for the same chemistry in certain product forms.

What makes 2.4066 valuable is not strength — at roughly 380–520 MPa tensile in the annealed condition it is weaker than mild steel. Its value is chemical. Pure nickel forms a passive, tightly adherent film in alkaline environments and is essentially immune to caustic attack, which is why it is the reference material for sodium hydroxide evaporators and for the anode and cathode hardware in chlor-alkali plants. It is equally the standard material for dry chlorine and dry hydrogen chloride gas, where nickel chloride forms a protective scale rather than a corroding one.

2.4066 is ferromagnetic below its Curie point of about 360 °C, and it has thermal and electrical conductivity roughly four times higher than austenitic stainless steel. Those two properties give it a second life outside chemical plant: magnetostrictive transducers, electronic lead wires, battery tabs, plater bars and heat-transfer hardware.

What Are the Equivalents of 2.4066? (Nickel 200, N02200, NW2200, NA11)

2.4066 appears on drawings under at least a dozen names depending on which standards body wrote the specification. Every designation below refers to the same commercially pure nickel. Jiangyin Jiangnan Metal Co., Ltd. supplies against any of them.

What Is the Chemical Composition of 2.4066?

The composition below is per ASTM B160 / B564 for UNS N02200, which is the reference most mills certify against. EN Ni 99.2 (2.4066) limits are essentially identical. Every element other than nickel is capped, not targeted — this is a purity specification, not an alloy recipe.

Typical mill analysis on our 2.4066 heats runs Ni ≈ 99.4 %, C ≈ 0.06–0.10 %, S ≤ 0.005 %, Fe ≈ 0.10–0.20 %. Actual heat analysis is reported on the EN 10204 3.1 certificate.

How Do ASTM B160, EN 2.4066, JIS NW2200 and GB N6 Differ?

Most supplier pages call these identical. They are not quite. The differences are small but they matter when a European or Chinese certificate has to be accepted against an American purchase order.

The practical consequence: a heat produced to Chinese GB N6 purity automatically satisfies ASTM B160, EN 2.4066 and JIS NW2200, because every one of its limits is tighter. The reverse is not true — an ASTM-only heat running Ni 99.1 % will fail a GB N6 acceptance. If you need a single certificate accepted in several jurisdictions, tell us at RFQ stage and we will procure to the tightest applicable limit and list all satisfied designations on one MTC.

What Are the Mechanical Properties of 2.4066?

Nickel 200 is not a structural material. It is specified for its chemistry and supplied in the annealed condition unless there is a reason not to. The table below separates specification minimums (what a certificate must show) from typical values (what the material actually does).

Elevated-temperature strength

Nickel 200 loses strength steadily with temperature and, because of the graphitization limit, it has no design life above 315 °C in the ASME code sense. Indicative typical tensile values: about 430 MPa at 20 °C, 400 MPa at 200 °C, 340 MPa at 315 °C. At cryogenic temperatures the material behaves well — it is face-centred cubic and does not go through a ductile-to-brittle transition, so 2.4066 stays tough down to liquid-helium temperature.

What Are the Physical Properties of 2.4066?

Two numbers on this table do most of the work in application engineering: the thermal conductivity of about 70 W/m·K (roughly 4.5× austenitic stainless, which is why nickel evaporator tubes transfer heat so well) and the Curie temperature of 360 °C (below which the material is magnetic — a frequent surprise for engineers who expect "nickel alloy" to mean "non-magnetic").

2.4066 vs 2.4068 — When Do You Need Nickel 201 Instead?

This is the single most common specification error on commercially pure nickel orders, so it is worth stating plainly. 2.4066 (Nickel 200) and 2.4068 (Nickel 201) are the same material except for carbon. Nickel 200 allows up to 0.15 % C; Nickel 201 caps it at 0.02 %. That single difference decides where each grade may be used.

How Corrosion-Resistant Is 2.4066? (Caustic, Chlorine, Acids, Seawater)

Commercially pure nickel is a reducing-condition material. It performs superbly where oxygen and oxidising ions are absent, and poorly where they are present. That single principle predicts almost every entry in the table below.

Where 2.4066 is the best available choice

• Sodium hydroxide at every concentration, including molten NaOH. Nickel is the reference material for caustic evaporators, concentrators and storage. Corrosion rates stay below 0.025 mm/year in 50–75 % NaOH at boiling. Above about 300 °C in strong caustic, welded assemblies should be stress-relieved to avoid caustic stress-corrosion cracking, and Nickel 201 becomes the correct grade.
• Dry chlorine and dry hydrogen chloride gas to about 550 °C (in the 2.4068 grade; keep 2.4066 below 315 °C). The nickel-chloride scale that forms is protective and self-limiting. This is why chlor-alkali plants specify nickel for dry-gas headers, valves and flanges.
• Neutral and alkaline salt solutions, molten salts, and food-contact service where the product must not pick up iron or discolour.
• Fluorine, hydrogen fluoride and fluoride salts under anhydrous conditions.
• Distilled and deionised water, and alkaline organic compounds such as alcoholates and phenol.

Where 2.4066 must not be used

• Oxidising acids — nitric acid attacks nickel rapidly at any concentration.
• Oxidising salt solutions — ferric chloride, cupric chloride, mercuric chloride, hypochlorite. These are aggressive even in dilute form.
• Aerated ammonia and ammoniacal solutions above roughly 1 % NH₃ — nickel forms soluble ammine complexes.
• Sulfur-bearing atmospheres above 315 °C — nickel-sulfide eutectic at 645 °C causes catastrophic intergranular failure. See the sulfur section.
• Stagnant, aerated seawater — nickel is not immune to chloride pitting and crevice attack when flow stops. Moving seawater is acceptable; dead legs are not. Monel 400 is the correct upgrade.
• Wet chlorine — the moment water is present the protective chloride scale dissolves. Titanium or a high-molybdenum nickel alloy is required.

How Is 2.4066 Forged and Heat Treated?

Pure nickel forges easily — it is soft, ductile and has a wide working range — but it is unforgiving about furnace atmosphere. Get the atmosphere wrong and the billet cracks apart on the first blow. The parameters below are what we run in production.

Forging window

• Working range: 650–1230 °C (1200–2250 °F).
• Heavy reduction: above 870 °C, ideally 1050–1200 °C, where the metal moves freely.
• Finishing: 650–870 °C with light reductions. Finishing hot and then air-cooling produces a coarse grain; finishing in this lower band gives a fine, uniform structure and better ultrasonic response.
• Never finish below 650 °C — the metal work-hardens quickly and surface cracking follows.
• Forging ratio ≥ 4:1 from the cast ingot to break down the as-cast structure. Rolled rings are upset, punched and expanded on a radial-axial mill.

Furnace atmosphere — the part that actually matters

Heat treatment

Atmosphere for annealing: reducing, ideally dry hydrogen or dissociated ammonia, to keep a bright finish. Partially burned natural gas is acceptable and cheaper. Never anneal in a sulfur-bearing atmosphere. Because nickel conducts heat so well, heating rates are fast and soak times can be shorter than the equivalent stainless part.

Why Does Sulfur Destroy Nickel Forgings?

It is worth spending a paragraph on this because it is the failure mode that separates shops that forge nickel routinely from shops that occasionally try.

Nickel and nickel sulfide (Ni₃S₂) form a eutectic that melts at 645 °C — far below any sensible forging temperature. Sulfur atoms diffuse rapidly along nickel grain boundaries. Once there, they form that low-melting phase, and at forging heat the grain boundaries are literally liquid. The billet then splits along the boundaries under the first significant reduction. The fracture surface is intergranular and shiny, and it is often misdiagnosed as a raw-material defect.

Sources of sulfur that have caused real failures:

• Fuel oil or high-sulfur gas in the reheat furnace.
• Sulfurised or chlorinated cutting oil left on a part before annealing — the classic one. Degrease before every heat treatment.
• Layout dye, marker crayon, temperature-indicating paint containing sulfur compounds.
• Grease and hydraulic oil on manipulator tongs and die faces.
• Rubber, PVC or adhesive tape residue.

How Do You Machine and Weld 2.4066?

Machining

Nickel 200 machines like a soft, gummy, moderately work-hardening metal — closer to annealed 304 than to carbon steel, but with a stronger tendency to smear and build up on the cutting edge. The rules that work:

• Take a real cut. The tool must get under the previously work-hardened layer on every pass. Rubbing or dwelling hardens the surface and destroys the next pass. Depth of cut 1.5–3 mm for roughing, never less than about 0.4 mm for finishing.
• Sharp, positive-rake, honed carbide. Keep the edge keen; replace on wear rather than running to failure.
• Moderate speed, heavy feed. Typically 40–70 m/min for turning with coated carbide, feed 0.15–0.35 mm/rev.
• Rigid setup. Chatter work-hardens the surface faster than anything else.
• Flood coolant, generously. Chlorinated or sulfurised cutting oils give the best tool life — but they must be completely removed by alkaline degreasing before any heat treatment, or the sulfur will embrittle the part.

Welding

2.4066 is readily weldable by GTAW, GMAW, SMAW and SAW. Practical points:

• Filler metal: Nickel Filler Metal 61 — ERNi-1 per AWS A5.14 — for GTAW and GMAW; ENi-1 per AWS A5.11 covered electrodes for SMAW. The filler carries titanium to tie up nitrogen and prevent porosity; do not autogenously weld thick sections.
• No preheat required for normal thicknesses. Interpass temperature below about 150 °C.
• Post-weld heat treatment is not required for strength — but a stress relief at 480–650 °C is required for welded parts going into hot caustic, where residual weld stress plus concentrated NaOH above about 300 °C can produce caustic stress-corrosion cracking.
• Cleanliness is the whole job. Grease, paint, crayon, sulfur-bearing marker and shop dirt all cause cracking or porosity. Clean 25 mm either side of the joint to bright metal.
• Nickel weld pools are sluggish and do not wet out like steel — expect a narrower, higher bead and manipulate accordingly. Use a slightly wider groove angle than you would for carbon steel.

What Forged Products Are Available in 2.4066?

Jiangyin Jiangnan Metal Co., Ltd. produces 2.4066 / Nickel 200 through four routes, chosen by geometry and quantity. Open-die forging handles shafts, blocks and large discs. Seamless ring rolling on a radial-axial mill produces rings from 200 mm to 2,500 mm outside diameter — the most-ordered form in this grade, because caustic and chlor-alkali plant is full of flanged joints. Closed-die forging covers repeat-volume valve parts. Upset forging is used for short, large-section hubs and stub ends.

2.4066 Production Capability

Process flow — every 2.4066 forging passes these eight stages

Equipment used on nickel work

Which Standards and Certificates Apply to 2.4066 Forgings?

How to Specify a 2.4066 Forging Order

Seven lines on a purchase order remove almost all ambiguity from a commercially pure nickel enquiry. Missing any of them is what turns an eight-week order into a fourteen-week one.

1. State the grade generically. Write "UNS N02200 / W.-Nr. 2.4066 / Ni 99.2", not a brand name. Add "per ASTM B564" for forgings or "per ASTM B160" for bar.
2. Confirm 200 versus 201. If any part of the duty cycle exceeds 315 °C, specify 2.4068 / N02201 — or ask for dual-certified material. Say what the maximum metal temperature is; do not leave us to guess.
3. Give the drawing. A 2D drawing or 3D model with critical dimensions, tolerances, surface roughness and any grain-flow requirement.
4. Specify delivery condition. Annealed is the default and is right for almost all corrosion service. Specify cold-drawn plus stress-relief only where a higher yield is genuinely needed.
5. Define the NDE. Ultrasonic acceptance class per ASTM A388 or EN 10228-3, plus penetrant per ASTM E165 on machined surfaces. For pressure parts, cite the ASME Section V acceptance criteria.
6. Specify the certificate. EN 10204 3.1 is standard; state 3.2 plus the inspection body if third-party witness is required. Name any additional designations you want cross-certified on the same MTC.
7. Give quantity, target date and destination with the Incoterm (EXW Jiangyin, FOB Shanghai, CIF or DDP).

Top 10 Mistakes When Ordering 2.4066 Forgings

1. Using 2.4066 above 315 °C. The most expensive error in this grade. Graphitisation embrittles the part and the failure is usually sudden. Fix: specify 2.4068 / Nickel 201, or dual-certified material.
2. Transferring a stainless design without re-checking thickness. Annealed nickel yields at roughly a third of 316L. Fix: recalculate against ASME Section II Part D allowables.
3. Budgeting by volume at steel density. Nickel is 8.89 versus 7.85 g/cm³ — a 13 % weight error before you start. Fix: use the weight calculator.
4. Leaving sulfurised cutting oil on a part before annealing. Guarantees intergranular embrittlement. Fix: mandate alkaline degreasing before every heat-treatment operation, in writing.
5. Specifying magnetic-particle inspection. Requested out of habit from steel work; not the appropriate surface method here. Fix: specify liquid penetrant per ASTM E165.
6. Assuming "nickel alloy" means non-magnetic. 2.4066 is strongly ferromagnetic below 360 °C. Fix: if you need non-magnetic, this is the wrong grade entirely.
7. Putting 2.4066 into wet chlorine or an oxidising acid. Pure nickel is a reducing-service material. Fix: run the corrosion matrix before releasing the drawing.
8. Skipping stress relief on welded hot-caustic parts. Residual weld stress plus strong hot NaOH gives caustic stress-corrosion cracking. Fix: stress relieve at 480–650 °C and say so on the drawing.
9. Ordering against a trademark. Narrows the supply base to one mill for no technical gain. Fix: order against UNS N02200 / 2.4066 / ASTM B564.
10. Not naming the required certificate up front. Adding a 3.2 witness after production has started can cost four to six weeks. Fix: state EN 10204 3.1 or 3.2 and the inspection body at RFQ stage.

How Do You Call Out 2.4066 on an Engineering Drawing?

Copy this block into the material box of your drawing. It is accepted under ASTM, EN, JIS and GB practice and removes essentially all interpretation.

MATERIAL:      Commercially pure nickel, UNS N02200 / W.-Nr. 2.4066 / Ni 99.2
               Forgings per ASTM B564 (or DIN 17754). Bar per ASTM B160.
               Also satisfies: Nickel 200, Alloy 200, JIS NW2200, BS NA11.

CONDITION:     Annealed 760-870 °C, 30 min per 25 mm ruling section, air cool.
               // Specify stress relief 480-650 °C for welded parts in hot caustic.

MAX SERVICE T: ___ °C   // If above 315 °C, change material to 2.4068 / UNS N02201.

CLEANLINESS:   Sulfur-free processing. Alkaline degrease before every heat
               treatment. No sulfurised marking media in contact with the part.

NDE:           UT per ASTM A388 (or EN 10228-3), acceptance class ___
               PT per ASTM E165 Type I Method C on all machined surfaces.
               Do not specify magnetic particle inspection on this grade.

TESTING:       Tensile per ASTM E8 in the annealed condition.
               Grain size per ASTM E112, report only.

CERTIFICATE:   EN 10204 3.1 mill certificate.
               // Or 3.2 with third-party witness by ______________.

MARKING:       Heat number, grade, drawing number and standard, low-stress
               stamped or vibro-etched on a non-functional surface.

Where Is 2.4066 Used?

Glossary — 2.4066 and Commercially Pure Nickel

Frequently Asked Questions — 2.4066 / Nickel 200

Technical References

The chemistry, mechanical, physical, heat-treatment and corrosion data on this page are drawn from published specifications and standard engineering references. Test results reported on our material certificates are independent and traceable to calibrated equipment.

1. ASTM B160/B160M, Standard Specification for Nickel Rod and Bar, ASTM International, West Conshohocken, PA.
2. ASTM B564/B564M, Standard Specification for Nickel Alloy Forgings, ASTM International.
3. ASTM B161, B162, B163, B366, B725, B730, B775 and B829 — nickel pipe, tube, plate, sheet, strip and fittings specifications, ASTM International.
4. ASME Boiler and Pressure Vessel Code, Section II Part B (SB-160, SB-564) and Part D (allowable stresses), ASME, latest edition.
5. DIN 17752, Rods and bars of nickel and wrought nickel alloys; DIN 17754, Forgings of nickel and wrought nickel alloys; DIN 17750, Plate, sheet and strip, Deutsches Institut für Normung.
6. EN 10204:2004, Metallic products — Types of inspection documents, CEN, Brussels.
7. EN 10228-3, Non-destructive testing of steel forgings — Ultrasonic testing, CEN.
8. SAE AMS 5553, Nickel Sheet, Strip and Plate, SAE International.
9. JIS H 4551 / H 4552 / H 4553, nickel and nickel alloy product standards, Japanese Standards Association, Tokyo.
10. GB/T 5235 and GB/T 2882, Wrought nickel and nickel alloy products (grade N6), Standardization Administration of China.
11. Special Metals Corporation, Nickel 200 & 201 Technical Bulletin, publication SMC-061.
12. VDM Metals International GmbH, VDM Nickel 200 / VDM Nickel 201 Material Data Sheet.
13. ASM Handbook, Volume 2: Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM International, Materials Park, OH.
14. ASM Handbook, Volume 13B: Corrosion: Materials, ASM International — sections on nickel and nickel alloys in caustic and halogen service.
15. ASM Handbook, Volume 14A: Metalworking: Bulk Forming, ASM International — forging of nickel and nickel alloys.
16. AWS A5.14, Specification for Nickel and Nickel-Alloy Bare Welding Electrodes and Rods; AWS A5.11, Covered Welding Electrodes, American Welding Society.
17. ASTM A388, Standard Practice for Ultrasonic Examination of Steel Forgings; ASTM E165, Liquid Penetrant Testing; ASTM E112, Determining Average Grain Size; ASTM E381, Macroetch Testing, ASTM International.

Standards cited are the most recent revisions known at the date of the last page review. For procurement, always reference the revision in force at the contract date. All trademarks named on this page belong to their respective owners.

Jiangyin Jiangnan Metal Co., Ltd. (2026). "2.4066 / Ni 99.2 / Nickel 200 /
UNS N02200 Forging Parts — properties, forging practice and specification guide."
Jiangyin, Jiangsu, China. Last updated 8 August 2026.
https://www.steelforgepieces.com/Nickel-Alloy/2.4066.html