N6 nickel plate selection full solution| Ni200 pure nickel plate high temperature concentrated alkali + reducing acid exclusive zone| 6 types of applications +5 cases + domestic import prices

Published by Engineering Team, Shaanxi Qianyi Tuoda Technology Co., Ltd on 2026-07-25

Rooted in Baoji China Titanium Valley, Shaanxi Qianyi Tuoda deep-ploughed nickel, Titanium non-standard corrosion equipment for many years, Pure nickel sheet in N6, nickel clad plate, A large number of chlor-alkali has been accumulated in the field of nickel chemical equipment, lithium battery, Experience in hydrometallurgical projects.30% sodium hydroxide evaporator project of a caustic soda plant, Drawing requires N6 nickel plate (Ni200), Q235 carbon steel delivered by supplier, The equipment has been in operation for only 6 months, Large area corrosion perforation of carbon steel base metal and weld, Caustic soda medium leakage caused production line shutdown.The corrosion resistance of N6 nickel plate is much better than that of carbon steel under high temperature and concentrated alkali condition, so it is the best material for this kind of corrosion condition.the composition of N6 nickel plate is explain in detail in this paper, material property, Six application scenarios, Five real projects, Market prices and processing procurement pit-avoidance points, Equipment Engineer, Material procurement personnel collection consult.

core conclusionsCarbon content ≤0.10%) and N4 (Ni201), Carbon content ≤0.02%) belongs to industrial pure nickel, At high temperatures, concentrated alkali, For example, sodium hydroxide concentrations greater than 50%., potassium hydroxide system, Reducing acids without oxidizing agents, High temperature molten salt has unique advantages in these three working conditions.Titanium materials are prone to hydrogen absorption embrittlement under such conditions, Stainless steel is subject to general corrosion, Pure nickel materials are more suitable under such conditions.

N6 nickel plate basic composition and brand distinction.N6 is Ni200, the total content of nickel + cobalt is not less than 99.5%, and the upper limit of carbon content is 0.10%;N4 is Ni201, the total content of nickel + cobalt is not less than 99.9%, and the upper limit of carbon content is 0.02%.Manganese, iron, sulfur, silicon, copper as impurity elements, the two control indicators are basically the same.The core difference between N6 and N4 focuses on carbon content., N6 Long-term use temperature upper limit 315℃, The material is prone to graphitic embrittlement between 425-650℃, Heat treatment is required to relieve stress after welding is completedN4 low-carbon grade, no sensitization interval, can be used for working conditions above 315℃, the purchase price is 10%-15% higher than N6.Selection reference: working temperature does not exceed 315℃, and with post-weld heat treatment conditions, N6 is preferred;If the working temperature exceeds 315℃ or post-weld heat treatment cannot be carried out, N4 is selected.GB/T 5235-2021 shall be implemented for national standard system N6 and N4; American standard shall correspond to UNS N02200 and UNS N02201; ASTM grade shall be Nickel200 and Nickel201; European standard grade shall correspond to 2.4060 and 2.4061.

N6 three core applicable conditions.The first is the high temperature concentrated alkali scenario, which is also the most advantageous application field of N6.Sodium hydroxide in various concentrations, potassium hydroxide medium environment, N6 material corrosion rate less than 0.05mm per year, There is basically no obvious corrosion.20% boiling sodium hydroxide condition, N6 corrosion rate ≤0.02mm per year;50% boiling sodium hydroxide at about 150℃, corrosion rate ≤0.03mm per year;75% boiling sodium hydroxide condition, corrosion rate ≤0.05mm per year;400℃ molten sodium hydroxide environment, corrosion rate control within 0.5mm per year.The corrosion rate of carbon steel is extremely high under the same working condition, 316L stainless steel corrosion is obvious, Serious hydrogen absorption embrittlement will occur in titanium materials, N6/N4 is suitable for high temperature and concentrated alkali condition.The second is reducing acid condition without oxidant, normal temperature 10% sulfuric acid medium, N6 corrosion rate ≤0.2mm per year;Boiling 5% hydrochloric acid short-term availability, corrosion rate ≤0.3mm per year;Boiling 30% phosphoric acid corrosion rate ≤0.3mm per year.If the medium contains ferric iron, oxidizing ion such as divalent copper, N6 corrosion rate will obviously increase, TA9 titanium palladium alloy is recommended for this scenario.The third type is high temperature molten salt and electronic scene, molten alkali 500℃ working condition, N6/N4 is the appropriate material;Low carbon N4 high purity nickel can be used for semiconductor target, electronic components, Food-related scenarios can achieve controllable nickel ion dissolution risk.

Six typical application industries and equipment.Sodium hydroxide evaporator for chlor-alkali caustic soda industry, Adaptation 110-150℃ boiling lye, Relying on excellent alkali resistancePET industry for oxidation reactors and coolers, Suitable for 120℃ working condition of bromoacetic acid, Resistant to weak reducing acid corrosionLithium battery cathode material field Used in nickel cobalt sulfate solution evaporator, suitable for sulfate feed solution, no metal ion pollution;Glass bulb manufacturing industry for mold and glass stirring components, Suitable for melting glass of thousand degrees Celsius, High temperature resistance and reduced precipitationHydrometallurgical industry for nickel-cobalt electrodeposition cell, 60 to 80℃ nickel-cobalt sulfate feed solution, resistant to weak reducing acid;Used in nuclear power and electronic fields for nuclear island components and semiconductor targets, relying on high purity and low carbon characteristics, radiation resistance.According to the data of Nickel Cobalt Branch of China Nonferrous Metals Industry Association, The domestic market scale is about CNY 2.8 billion for N6 nickel plate products in 2024, Chlor-alkali and lithium sectors together account for 55%-60% of total N6 demand.

Five real-life projects.Case 1: 50% sodium hydroxide evaporator in a 600,000 tons/year caustic soda plant, equipment specification DN1200, length 4000mm, using 6mm thick N6 nickel plate, medium boiling concentrated alkali at 150 ° C.The original carbon steel lining scheme will be used for 6-12 months, and the lining will fall off and perforate., Replacement of N6 nickel plate equipment, match 600-650 DEG C post-weld annealing proces, Stable operation for 12 years, The whole set of equipment cost 80- 1.2 million yuan.Case 2, PTA device oxidation reactor, using N6 + Q345R explosive composite plate, specification DN 1500, length 3500 mm, medium 120 ℃ containing bromoacetic acid.The original 316L lining tetrafluorine-lined scheme failed in 3 - 5 years, Stable operation for 8 years after transformation, Composite plate cladding thickness 4mm, The whole set of equipment is 500,000 - 700,000 yuan.Case 3, lithium cathode material nickel sulfate evaporator, DN800 length 3000mm N6 shell evaporator, sulfate boiling liquid.Pitting and perforation occurred in original TA2 plate in 1 - 2 years, After N6 modification, stable operation for 6 years, No nickel ion pollution, Cost 350 - 500 thousand yuan.Case 4, N6 nickel mold for CRT bulb, Φ500 thick nickel plate, suitable for molten glass above 1000℃.Cast iron dies are easy to deform, contaminate the glass, N6 mold processing is not easy to deform after mirror polishing, The price of a single piece is 250,000 - 400,000 yuan.Case 5, Hydrometallurgical nickel-cobalt cell, Steel shell lined with 4mm N6 nickel plate, DN2000 Length 5000mm, Nickel cobalt sulfate feed solution containing trace chloride ions at 60-80℃.Rubber lining 2-3 years aging failure, N6 lining equipment stable operation for 8 years, the whole set of cost 800 -110 million yuan.

N6 nickel plate manufacturing process: plate incoming furnace batch number verification, re-inspection of carbon content and mechanical properties;2 - 3mm machining allowance is reserved by laser or waterjet NC blanking;Cold rolling, pressing molding, single deformation more than 25% need 700℃ intermediate annealing, to prevent molding cracking;Assembly after tooling positioning, Argon arc welding, 99.99% argon for welding, argon back protection600-650 DEG C for 1 - 2 hours after welding is completed, stress relief annealing is indispensable;Appearance inspection and 100% penetration inspection shall be carried out for welds, and radiographic inspection shall be added for key pressure-bearing parts;Use 20%-30% nitric acid pickling passivation, prohibit the use of hydrofluoric acid;Finally, hydrostatic test shall be carried out, the test pressure shall be 1.5 times of the design pressure, and the vacuum nitrogen-filled package shall be delivered.

N6 nickel plate related implementation standards: GB/T 5235-2021 specification nickel and nickel alloy brand composition;GB/T 2054-2013 is the nickel alloy sheet standard;GB/T 2882 and GB/T 4435 correspond to nickel tube and nickel rod respectively;ASTM B162, B160, B163 correspond to American standard nickel plate, rod, pipe;Refer to ASME BPVC Section VIII for pressure vessel design, and NB/T series standards for welding qualification, nondestructive testing and clad plate.

Domestic and imported N6 nickel plate price reference in the second quarter of 2026.Domestic N6 sheet thickness 2-4mm annealed plate unit price 200-235 yuan per kilogram, imported with specifications 380-460 yuan per kilogram;4-10mm medium plate domestic 185-220 yuan per kilogram;10-30mm thick plate domestic 180-215 yuan per kilogram;Φ20-100mm nickel rod domestic 180-205 yuan per kilogram;DN50-DN200 nickel tube made in China 200-240 yuan per kilogram.N4 high purity nickel plate domestic 220-260 yuan per kilogram.Bulk purchase of one ton and above, unit price can be reduced to 160-190 yuan per kilogram.Unit price of N6 material is TA2Titanium Plate2-3 times, nickel density is higher, the same volume of procurement costs will further increase.Domestic Jinchuan, Baoji nickel industry and other manufacturers can be stable supply, Nuclear power primary pressure, There is still a premium for imports of high-purity electronic grade products.

N6 plate procurement identification method is also the key point of industry procurement.First, XRF spectroscopy is used to detect nickel content., Genuine N6 nickel element test results are not less than 99.5%The second magnet test, pure nickel belongs to paramagnetism, magnets basically do not absorb, can quickly distinguish carbon steel;The third weighing density verification, N6 density 8.89g/cm³, compared to 316L stainless steel weight of about 12%, can assist in identifying counterfeit materials.The procurement contract shall specify the brand, nickel and carbon indicators, testing standards, and stipulate the third-party component testing report.

Material selection comparison: N6/N4 is preferred under high temperature concentrated alkali conditions, titanium materials cannot be used;Oxidiant-free reducing acid optional N6 or TA9;Chlorine-ion-containing seawater and brine have priority TA2;TC4 is selected for high strength pressure bearing component;Food scenes need to strictly control metal precipitation, giving priority to titanium materials;Low-carbon N4 is selected for high-purity electronic scenarios.

N6 processing five pit avoidance points.After welding without stress relief heat treatment, 1-2 years stress cracking of weld joint under concentrated alkali condition;The graphitization embrittlement of the material occurs when the material stays in the sensitization range of 425-650℃ for a long time during processing.Hydrochloric acid is chosen for pickling, which will rapidly corrode nickel materials;The deformation of single cold forming exceeds 25%, and the plate is easy to crack.The cutting speed is too high, the material work hardening is serious, and machining defects are produced.

The five major risks of procurement need to be guarded against: using carbon steel as N6 for supply, and piercing in a short time under concentrated alkali conditions;316L stainless steel instead of N6 delivery, pitting occurs under reducing acid conditions;Unnecessary scenarios choose high-priced N4, increasing procurement costs;N6 clad plate coating thickness reduction, bring welding through hidden danger;Do not verify the third-party test report, and the material composition is not up to standard.Procurement must specify the brand, element index, implementation standard, post-weld heat treatment requirements.

FAQ

Q1: How to choose between N6 and N4? Working temperature ≤315℃, can do post-weld annealing, select N6;If the temperature exceeds 315℃ or heat treatment is impossible, N4 shall be selected. Q2: Can N6 make heat exchangers? N6 heat exchanger is suitable for concentrated alkali and reducing acid working conditions;In salt water containing chloride ions, TA2 titanium material has higher cost performance. Q3: How about N6 tensile properties? Annealed N6 tensile strength is not less than 380MPa, yield ≥100MPa, elongation ≥40%, high strength pressure scene priority TC4 titanium alloy. Q4: Can N6 tolerate hydrochloric acid medium? Dilute hydrochloric acid at room temperature without oxidant can be used for short term;The medium contains ferric iron, copper ions and other oxidants, N6 is not recommended, TA9 titanium palladium alloy is selected. Q5: How to choose between domestic N6 and imported N6? The performance of domestic plate of conventional industrial anti-corrosion equipment is stable;Nuclear first-class pressure-bearing, ultra-high purity electronic grade materials can be considered imported brands.

Industry development trend: lithium cathode material demand continues to drive the N6 market;High-end N4 nickel plate domestic replacement process accelerated;N6 and Q345R, titanium clad plate, Can effectively reduce equipment manufacturing costs, It is the development direction of large-scale chemical equipment.

written in the end

N6 pure nickel is not a noble metal, it is a suitable material for high temperature concentrated alkali and reducing acid conditions.Higher material purchase unit price, But it can extend the service life of the equipment to 8-15 years, Comprehensive life cycle costs are more advantageous.Carbon steel is selected to replace N6 for concentrated alkali working condition, Corrosion perforation occurs in a short time, Not only caused shutdown losses, There are also hidden dangers in production safety. titanium products, Stainless Steel Constitutes Anti-corrosion Material Selection System, N6/N4 high temperature concentrated alkali, molten alkali, oxidant-free reducing acidTA2, TA10 and TA9 are suitable for chloride ion, seawater and wet chlorine environment;316L stainless steel used in clean water, low chloride ion normal conditions;TC4 is used for high-intensity lightweight pressure scenarios.

If you are in caustic soda, lithium battery, Equipment Selection for Hydrometallurgical Project, Technical docking and procurement quotation, This selection information can be used as a design institute, Manufacturer technical communication reference.

Shaanxi Qianyi Tuoda Technology Co., Ltd. is located in Baoji, China Titanium Valley, More than ten years of deep cultivation in the customization of nickel-titanium non-standard anti-corrosion equipment, N6 nickel plate available, Selection of nickel composite plate equipment working conditions, panel processing, Welding process kit, On-site technical consultation one-stop service.

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disclaimerMaterial parameters in this paper, price range, The project case is only used as a reference for technical selection, Does not constitute a technical commitment and commercial offer.The actual use effect of materials is affected by medium concentration, temperature fluctuation, processing and welding technology, and field operation and maintenance conditions.Shaanxi Qianyi Tuoda Technology Co., Ltd. reserves the right of final interpretation of this article.Technical consultation: 15909236031 / 0917-3557966.