Complete Solution of Hastelloy C276 Selection| Ni-Mo-Cr Severe Corrosion Conditions

Published by Engineering Team, Shaanxi Qianyi Tuoda Technology Co., Ltd on 2026-07-28

Rooted in Baoji China Titanium Valley, Shaanxi Qianyi Tuoda Long-term Service Chemical, wet-process phosphoric acid, flue gas desulphurization project, Accumulated a lot of engineering experience in the selection of strong corrosion special alloys.When many chemical projects encounter mixed strong acid medium, TA2, TA10 titanium, N4, N6 pure nickel and 316L, 904L stainless steel are difficult to meet the long-term use needs, Hastelloy C276 has become the preferred material for such severe conditions.A WPA Concentration Section, The medium is 30% phosphoric acid and 5% hydrofluoric acid., Temperature 50℃ and contains solid particles, Conventional titanium, Nickel will corrode rapidly, However, Hastelloy C276 of Ni-Mo-Cr ternary system can cope stably., This is wet phosphoric acid., wet chlorine preheater, The reason why this alloy is often selected for hypochlorous acid reactor projects.This paper systematically explains the composition characteristics of Hastelloy C276, Six applicable scenarios, Comparison with titanium nickel material, project case, Domestic and foreign material price reference, For process engineers and purchasers reference.

core conclusionsHastelloy C276 is not a substitute for ordinary expensive titanium and nickel, titanium., nickel, Stainless steel is difficult to withstand the conditions of the material adaptation.wet-process phosphoric acid, hydrochloric acid containing oxidant, hypochlorite, High temperature wet chlorine four corrosion environment, C276 has outstanding corrosion resistance.

Hastelloy C276 grade national standard for NS334, UNS number N10276, American standard sheet ASTM B575, bar ASTM B574, pipe selection B622, B619, European standard grade 2.4819.Alloy matrix nickel content is not less than 57%, molybdenum content 15.0-17.0%, chromium content 14.5-16.5%, matching tungsten, iron and other elements, carbon content controlled within 0.01%.Molybdenum element resists hydrochloric acid, sulfuric acid, phosphoric acid and other reducing acids;Chromium element forms stable passivation layer in medium containing oxidant;High nickel matrix resists high temperature concentrated alkali and stress corrosion cracking, Three Synergies, So that C276 can give consideration to oxidation and reduction of mixed corrosion conditions.

Six typical adaptation scenarios cover most of the strong corrosion chemical projects.The first type is wet phosphoric acid containing hydrofluoric acid, Hydrochloric acid will quickly destroy titanium passivation film, the resistance of common nickel to hydrofluoric acid is also limit, C276 corrosion rate controllable under this conditionThe second type of oxidizing agent containing dilute hydrochloric acid environment, Titanium contains iron ions, Corrosion perforation occurs in a short time in hydrochloric acid environment of copper ions, C276 passivation film can resist corrosion from such mediaClass III hypochlorous acid, sodium hypochlorite system, It belongs to strong oxidizing medium, Titanium Not applicable, Ordinary stainless steel has a limited service lifeClass IV 80-150℃ high temperature wet chlorine, TA10 is only suitable for wet chlorine up to 80℃, C276 is preferred for higher temperature conditionsThe fifth kind of chloride ion is mixed with hydrofluoric acid, and it is difficult for conventional metal materials to balance two kinds of corrosion ions.Class VI High Concentration Hydrochloric Acid, sulfuric acid environment, Titanium material cannot be used under concentrated acid condition at normal temperature, C276 can be used stably under concentrated hydrochloric acid condition within 65℃.

From the perspective of industry applications, wet-process phosphoric acid extraction tank, concentrator, Hypochlorous acid production reactor and pipeline, flue gas desulphurization absorber, slurry line, Chlorine dioxide reaction equipment for pulp bleaching, Offshore oil and gas downhole pipe, submarine valve, Pesticide Pharmaceutical Reactor and Concentrator, This is a common scenario for C276.The domestic market for C276 products has maintained steady growth, with wet phosphoric acid and flue gas desulfurization accounting for more than 60% of the demand.

Compared with TA10 and N6 pure nickel, only C276 can be used stably under the condition of wet phosphoric acid containing hydrofluoric acid.Containing oxidant hydrochloric acid, hypochlorous acid conditions, titanium, pure nickel corrosion resistance is insufficient;80-120℃ wet chlorine scene, C276 adaptation temperature range is wider;N4 pure nickel is more suitable for high temperature concentrated alkali condition;TA10 is more cost-effective for chlorine-containing medium in ordinary seawater.According to the market conditions in the second quarter of 2026, the domestic C276 sheet price is 320 - 380 yuan per kilogram, the medium plate is 300 - 360 yuan per kilogram, the thick plate is 290 - 340 yuan per kilogram, the rod is 280 - 330 yuan per kilogram, and the seamless pipe is 350 - 420 yuan per kilogram.The price of imported materials of the same specification is generally about 80% higher than that of domestic materials, and the import price of flange forgings is nearly twice that of domestic materials.C276 is 2.5 to 3 times more expensive than TA10 titanium, Industrial grade domestic C276 made of titanium, Fushun Special Steel, Pangang stable supply, Imported Haynes materials are mostly used for nuclear power first-class working conditions, The VDM product.

Three landing engineering cases can visually refer to the effect of material selection.C276 reactor for concentration section of wet-process phosphoric acid device, The medium contains phosphoric acid and hydrofluoric acid, The original TA 2 liner scheme failed to fall off for half a year, After replacing C276 whole equipment, long-term operating stabilityFlue gas desulfurization C276 absorption tower, The slurry contains chloride ions and sulfuric acid, The original glass flake anti-corrosion 2-3 years off, C276 composite plate, Substrate Q235 with 3mm multilayer, Equipment life cycle greatly increasedSodium hypochlorite production reactor, medium sodium hypochlorite with sodium hydroxide, TA2 titanium material only 3 months perforation, change to C276 reactor, matching the same brand ERNiCrMo-4 welding wire, equipment stable operation.

C276 processing technology and titanium material are quite different, The hot working temperature range needs to be controlled at 1120-1170℃, Temperature shall not exceed 1230℃, Avoid coarse grains and reduce corrosion resistanceAfter welding, solution annealing at 1140-1170℃ and rapid cooling must be carried out to eliminate the risk of sensitization.Material cutting easy work hardening, Cutting speed needs control, ERNiCrMo-4 special welding wire is selected for welding, Welding shield argon purity 99.99%, The interlayer temperature is controlled within 150℃.Finished products require visual inspection, penetrant testing, Increase radiographic inspection of critical welds, Then subjected to acid pickling and passivation treatment, After completion of hydrostatic test, it can be delivered from factory.time of purchase, The order needs to be clearly marked, executive standard, element content, Welding wire type and solution annealing process, Avoid fake materials.

There are many aspects of procurement and processing that need attention.Hot working temperature exceeds standard, Omit post-weld solution annealing, Wrong wire selection, Cutting speed too fast, XRF element reinspection is not required upon arrival., All are common problems in the processing stage.procurement, Market presence 316L, N6 pure nickel, TA10 Titanium impersonates C276, It will fail quickly under severe corrosion conditions.Molybdenum can be detected by XRF upon arrival acceptance, chromium, nickel element content, Fit Density Test, If necessary, corrosion immersion test shall be conducted to verify the material.The purchase contract must indicate the brand number, ASTM standard, primary element index, Welding wire specification and heat treatment requirements, Any parameter missing is liable to cause project losses.

Frequently Asked Questions

Q1: How to choose between C276 and TA10?Medium containing HF, containing oxidant hydrochloric acid, hypochlorous acid priority C276;TA10 was selected for pure chloride ion and wet chlorine under 80℃. Q2: Is C276 post-weld heat treatment necessary?Solution annealing is a key process to ensure corrosion resistance and cannot be omitted. Q3: How to choose domestic and imported C276?Conventional chemical industry projects have outstanding domestic cost performance, and high-end nuclear power pressure conditions can be considered imported.

written in the end

Hastelloy C276 is a special nickel-base alloy for dealing with multiple strong corrosive media, Although material procurement costs are higher, But in titanium, nickel, Mixed acid environments that stainless steel cannot tolerate, It can effectively reduce equipment replacement and downtime maintenance costs.titanium, pure nickel, Hastelloy forms a complete corrosion resistant material ladder, binding medium component, temperature, Integrated pressure assessment, and the corrosion resistant material with proper cost performance can be selected.If you are using wet phosphoric acid, flue gas desulfurization, Equipment selection for sodium hypochlorite project, Technical communication and procurement quotation, Refer to ASTM C276, Heat treatment process and market price range.Shaanxi Qianyi Tuoda relies on Baoji Titanium Valley Industrial Advantage, Titanium available, Nickel base corrosion resistant alloy selection consultation, Non-standard processing services.

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disclaimerThe technical parameters, price range and project cases in this article are only for technical selection reference, and do not constitute technical commitment and commercial quotation.The actual service cycle of equipment is affected by medium concentration, temperature fluctuation and operation and maintenance conditions.Shaanxi Qianyi Tuoda Technology Co., Ltd. reserves the right of final interpretation of this article.Technical consultation: 15909236031 / 0917-3557966.