The method of protecting steel against corrosion in aqueous environments
(57) Abstract:The invention relates to corrosion protection and can be used to protect equipment from steel under the action of aggressive media that are close to neutral. The developed method is the introduction working in the aquatic environment complex inhibitor whose components have the following concentrations in the environment, g/DM3: sodium nitrite 50 - 100, water-soluble urea-formaldehyde resin (brand KF-W, GOST-14231-88) 10 - 20; orthophosphoric acid, 10 - 20. The way to protect steel from corrosion, has a high protective characteristics, relatively low concentrations of reagents, which are low-toxic substances and have a lesser impact on the environment. At these concentrations the observed corrosion rate was less than 0.005 mm/year, a protective effect is greater than 95%. 2 C.p. f-crystals, 1 table. The invention relates to the field of corrosion protection and can be used for protection of parts and equipment in water circulation systems of various types. In particular, it can be used for corrosion protection of heat networks in the summer (Parking mode), to protect stations in the calibration of instrumentation and gozdarstva aggressive environment (water) . In addition to stabilization, de-aeration, water desalination, which, as a rule, expensive and labor-intensive, widespread methods based on the use of corrosion inhibitors. As inhibitors used individual inorganic and organic compounds or composition of several substances . Among inorganic inhibitors widespread found chromates (bichromate), wolframate, molybdates, vanadates, alkaline metals and zinc . Despite the high efficiency in a neutral environment, these inhibitors are toxic and expensive reagents. In addition, in the presence of chlorine ions, they can cause pitting corrosion [4, S. 293]. It is also known the use of polyphosphates and hypophosphate sodium. However, such inhibitors are ineffective in terms of Parking corrosion [1, S. 49] and their concentration should be maintained at a sufficiently high that a specific level, because at low concentrations they cause harmful manifestations of pitting corrosion, and at too high concentrations may even encourage corrosion [1, 50 C.].Phosphoric acid in an individual state is used for phosphating, as the inhibitor is not applied. N is Noah acid and zinc salts . However, this method requires high acid concentration (up to 100 mg/DM3), which in low concentration of zinc ions cause severe corrosion.It is also known the use of sodium nitrite as a one-component corrosion inhibitor, and in the composition of the inhibitor compositions [2, 112 S. and more]. However, in these cases, the sodium nitrite is used in high enough concentrations, because if its lack of hard runs pitting corrosion. For example, for the protection of steel in neutral water containing Na2SO4(0,1 N), the required concentration of NaNO2more than 10 g/DM3[4, S. 295]. In idle modes of heat transfer equipment requires the same concentration of sodium nitrite [1, S. 77].Water-soluble polymers are also used as corrosion inhibitors, and, as a rule, the composition of the inhibitor compositions. For example, certain water-soluble phenol-formaldehyde resin in combination with salts of zinc or polyphosphates . However, this method requires a high concentration of expensive inhibitor is a phenol-formaldehyde resin-based resorcinol or salicylic acid.Closest to the proposed tehnicheskie in the aquatic environment inhibitory composition based on sodium nitrite and diamine  (prototype). To implement this method for the protection of steel equipment vagocirculatory system introduce the following quantities of reagents:
sodium nitrite 1 - 10 g/DM3;
hexamethylenediamine were 0.01 to 1 g/DM3.The disadvantages of the prototype method:
1. The high cost of reagents and their high concentration in the working environment.2. High toxicity diamine.3. This composition does not protect against pitting corrosion at lower concentrations of sodium nitrite.4. Hexamethylenediamine were one of the most difficult and expensive reagents.The purpose of the invention is development of a method of protecting steel against corrosion in aqueous media with high protective performance, using available low-toxic reagents having a relatively low concentration.This goal is achieved by introducing working in the aquatic environment inhibitor composition, the components which have the following concentrations in the environment:
sodium nitrite 50 - 100 g/DM3;
water-soluble urea-formaldehyde resin (brand KF-W, GOST-14231-88) 10 - 20 g/DM3;
phosphoric acid 10 - 20 g/DM3.Significant excellent is my urea-formaldehyde resin, in the presence of minor amounts of phosphoric acid gives a high protective effect. When used, the concentration of sodium nitrite is considerably lower (3 to 100 times) than the commonly used concentration.As water-soluble urea-formaldehyde resin used resin brand KF-W GOST-14231-88. In the used concentrations of the resin gives a stable aqueous solutions.The advantages of the proposed method are the following:
1. All three components of the inhibiting compositions are available and relatively cheap reagents.2. The offered chemicals are toxic and are widely used in other areas.3. Concentrations of reagents and therefore their costs are lower than typically used for nitrite and phosphoric acid.4. The decrease in the concentration of the reactants below the recommended limits does not entail a sharp increase in corrosion rate.Implementation of the proposed method of protecting steel against corrosion in aqueous environments carried out in the laboratory using the gravimetric method, recommended for Parking modes . Samples of the Article. 20 cylindricus, in which you have entered inhibitory components of the composition at a concentration indicated in the table for each example. The concentration of KF-W obtained using the commodity form, containing 64% of the polymer. Phosphoric acid and sodium nitrite are used as reagents brand "chemically pure".The samples were completely immersed in water, mixing is not used.As a working environment used tap water with a total dissolved solids 150 - 230 mg/DM3. The solutions after the introduction of the inhibitor compositions had a pH of 6.3 and 7.5. The duration of the experiment 100 hours At the table presents data on the corrosion protection of the proposed method.As can be seen from the table, the proposed method of protection against corrosion by introducing inhibitory composition provides effective protection of steel samples ( 100%). The increase in the concentration of the components above these limits does not give a significant increase in the protective effect and impractical from the point of view of consumption of reagents. The decrease in concentrations below the proposed levels reduces the protective effect.Sources of information
1. P. A. Akol'zin. The prevention of corrosion of equipment technical water and talona, 1968.3. I. L. Rosenfeld. Corrosion inhibitors.- M.: Khimiya, 1977.4. Protection against corrosion, aging and biodegradation of machinery, equipment and structures. Reference book/ Ed. by A. A. Gerasimenko. T. 2.- M: Engineering. 1987.5. Pat. USA 4018701, 1977 (P. H. Ralston, B. P. Boffard).6. Pat. USA 4014814, 1977 (D. C. Zecher).7. Centuries of Flowers and other corrosion Inhibition of metals systems recirculating water. Chemical and pharmaceutical journal, 1994, No. 5, S. 50 (prototype).8. P. A. Akol'zin. Control corrosion of boilers.- M.: Energoatomizdat. 1994, c. 115. 1. The method of protecting steel against corrosion in aqueous environments, including the introduction in aggressive environment inhibitory composition based on sodium nitrite and nitrogen-containing organic compounds, characterized in that as the nitrogen-containing compounds using water-soluble urea-formaldehyde resin, and optionally in the environment enter phosphoric acid.2. The method according to p. 1, characterized in that the components of the inhibiting composition is administered in the following concentrations, g/DM3:
Sodium nitrite - 50 - 100
Water-soluble urea-formaldehyde resin (brand KF-W, GOST-14231-88) - 10 - 20
Phosphoric acid - 1 is used by the resin grade KF-J.
FIELD: inhibitors for prevention of formation of carbonate, sulfate and iron oxide deposits and breaking these deposits in circulating cycles of cooling systems, wet scrubbing of gases, heat supply systems and hydraulic transport facilities.
SUBSTANCE: proposed inhibitor contains the following components, mass-%: phosphate inhibitor, 5-40; phosphonate inhibitor, 5-40; anhydrous hygroscopic salt of alkaline or alkaline-earth metals of inorganic acids whose molecule may add-on 4-12 molecules of water, for example, sulfates and carbonates of sodium, potassium, calcium, the remainder being sodium and potassium orthophosphates. Inhibitor contains, mass-%: water-soluble polymer (molecular mass 3000-20000), 5-40; anhydrous hygroscopic salt of alkaline or alkaline-earth metals of inorganic acids whose molecule may add-on 4-12 molecules of water, for example sulfates and carbonates of sodium, potassium and calcium; the remainder being sodium and potassium orthophosphates.
EFFECT: possibility of obtaining inhibitor in solid state in form of tablets or granules due to improved contact of particles.
9 cl, 3 ex
FIELD: inorganic chemistry.
SUBSTANCE: invention refers to the method of corrosion inhibiting in water systems. To the industrial water system it is added the mixture on the base of phosphine- succinic acid which consist the following elements: mono-, bis-, and oligomerous adducts of the phosphine- succinic acid. In the ratio of the phosphine- succinic acid are: 36-49 mole percent bis-adducts of the phosphine- succinic acid and 27, 28, 29, 31, 34.6 or 35 mole percent of the oligomerous adducts of the phosphine- succinic acid.
EFFECT: increasing of the efficiency on inhibiting of corrosion.
3 cl, 3 tbl, 7 ex
SUBSTANCE: method involves interaction of untreated gas with water solution of 2-(2-aminethoxy)ethanol containing organopolysiloxane composition with polyoxyalkylene group, and fine silica powder. Additive for water solution of 2-(2- aminethoxy)ethanol includes organopolysiloxane composition with polyoxyalkylene group, and fine silica powder in the amount of 0.1 to 5000 parts per mln, while the water solution includes 40 wt % or over of 2-(2- aminethoxy)ethanol.
EFFECT: anticorrosion protection of steel parts of a device for acid gas removal with foam-reducing effect.
7 cl, 5 dwg, 2 ex
SUBSTANCE: invention relates to field of steel protection against corrosion and can be used for protection of overpasses, railway and highway bridges and other metal constructions and structures. Inhibitor contains, wt %: polyoxyethylene 0.001-0.1; bentonitic clay 0.5-4.0; soda ash 0.1-1.0 and water - the rest. Method includes introduction into water solution polyoxyethylene with concentration 0.9-1.0 wt % soda ash solution with concentration 0.9-10 wt % and reduction of pH till -9, after what with the rate 1 l/min it is introduced aqueous suspension solution of bentonitic clay with concentration 5-10 wt %. Then it is added water for receiving of required inhibitor concentration. Process is implemented with constant mixing at 18-22°C. Into the composition there are entered accessible components and method of receiving is simple and low-cost. Final product refers to low-hazard substances.
EFFECT: development of simple and economical method of steel protection against corrosion.
2 cl, 2 ex
SUBSTANCE: invention is intended for protection of steel constructions and facilities against atmosphere corrosion. Inhibitor contains the following, wt %: carboxymethyl cellulose 0.15-0.5; bentonitic clay 0.5-1.0; water - the rest. In the method, as water-soluble polymer, there used is swollen concentrated water solution of carboxymethyl cellulose with degree of polymerisation of 700-900 with content of polymer of 1.5-5.0 wt %, which is mixed with equal quantity of concentrated swollen water solution of bentonitic clay with clay content of 5-10 wt %; then the obtained mass is mixed till homogeneous composition is obtained, and immediately before it is used, there added is design amount of water till the above specified inhibitor is obtained, an the obtained compound is mixed till it is homogeneous.
EFFECT: application of popular cheap polymer and other cheap non-toxic components, simplifying the method, possibility of obtaining the inhibitor at working station.
2 cl, 2 ex
SUBSTANCE: inhibitor contains, wt %: polyoxyethylene with molecular weight 105-8·106 0.0005-0.01; modified bentonite with contents of montmoryllonite 80% and over 0.1-0.5; soda ash 0.002-0.02 and water - the rest. The procedure consists in loading concentrated water solution of polyoxyethylene of molecular weight 105-8·106 and concentration 0.01-0.2 wt % into a reservoir equipped with a mixer and pH metre. Further, the process is carried out with an operating mixer. Concentrated water solution of soda ash is added at concentration 2-4 wt %; pH is brought to 8-9, water suspension solution of modified bentonite is introduced at rate not over 2 l/min where contents of montmorillonite is 80 % and concentration - 1-2 wt %. Produced mass is mixed during 3-5 min and there is added calculated amount of water.
EFFECT: simplified production of inhibitor, reduced time for production, reduced consumption of reagents and improved hygienic and ecological properties of inhibitor composition.
2 cl, 2 ex
SUBSTANCE: inhibitor contains, wt %: poly-acryl-amide with molecular weight 104-107 0.0005-0.01; modified bentonite with contents of montmoryllonite 80% and over 0.1-0.5; soda ash 0.01-0.02 and water - the rest. The procedure consists in loading concentrated water solution of water soluble polymer corresponding to poly-acryl-amide of molecular weight 104-107 and concentration 0.01-0.2 wt % into a reservoir equipped with a mixer and pH metre. Further, the process is carried out with an operating mixer and concentrated water solution of soda ash is added at concentration 2-4 wt %; pH is brought to 8-9, water suspension solution of modified bentonite clay is introduced at rate not over 2 l/min where contents of montmorillonite is 80% and concentration 1-2 wt %. Produced mass is mixed during 3-5 min and there is added calculated amount of water.
EFFECT: inhibitor possesses high safety and corresponds to bio-decomposed substance with high protective properties of steel items from corrosion.
2 cl, 1 ex
SUBSTANCE: composition contains, wt %: poly-acryl-amide-gel 0.01-0.02, modified bentonite with contents of montmoryllonite 80 % and over 0.1-0.5 and water - the rest. The procedure for production of inhibitor consists in introducing solution of water suspension of modified bentonite of concentration 2-20 wt % into concentrated water solution of poly-acryl-gel of 0.6-2.5 concentration at operating mixer and at rate of supply not more, than 2 l/min. Calculated amount of water is added into produced mass and is mixed during 3-5 min. If necessary, in field conditions water can be added directly before inhibitor usage. Insignificant concentrations of general access non-toxic components are present in the composition. The finished product is referred to low-hazard bio-de-composed substances.
EFFECT: high protective properties of steel items from corrosion.
2 cl, 1 tbl
SUBSTANCE: method of producing steel corrosion inhibitor base on water-soluble polymer comprises filling cylindrical container with conical bottom with outlet in its lower part by 15-25% of water, polyoxyethylene, soda ash, bentonite clay and adding preset amount of water. Note here that process is carried on at 5-45°C with permanent mixing and forced circulation for 5-10 min after adding soda ash.
EFFECT: simplified procedure.
1 dwg, 1 ex
SUBSTANCE: invention relates to an oxidised and maleated tall oil composition, as an emulsifier or corrosion inhibitor, containing tall oil having at least two C10-C24 structures, where at least one of the C10-C24 structures is substituted with at least one α,β-unsaturated carboxylic acid or anhydride, wherein the C10-C24 structures are cross-linked by an ether bond, and where the oxidised and maleated tall oil composition has acid number from about 50 mg KOH/g to about 400 mg KOH/g. The invention also relates to the following methods: production of an oxidised and maleated tall oil composition, as an emulsifier or corrosion inhibitor, containing tall oil having at least two C10-C24 structures, where at least one of the C10-C24 structures is substituted with at least one α,β-unsaturated carboxylic acid or anhydride, wherein the C10-C24 structures are cross-linked by an ether bond, and where the oxidised and maleated tall oil composition has an acid number from about 50 mg KOH/g to about 400 mg KOH/g, involving providing tall oil having at least two C10-C24 structures, maleating the tall oil and oxidising the tall oil; to emulsification of a solution, including a step of combining the solution with an effective amount of the oxidised and maleated tall oil composition; to inhibition of corrosion on a metal surface, involving contacting the metal surface with an effective amount of the oxidised and maleated tall oil composition; and to reducing corrosion of a metal surface, involving contacting the metal surface with an effective amount of the oxidised and maleated tall oil composition.
EFFECT: obtaining an oxidised and maleated tall oil composition.
18 cl, 7 ex, 6 dwg
FIELD: agent for metal corrosion protection, in particular uranium part protection from crumbling oxide corrosion and hydrogen corrosion.
SUBSTANCE: claimed composition contains (mass %): water-soluble manganese(VII) compound 1.5-6.0 and water 94.0-98.5.
EFFECT: more effective uranium part hydrogen corrosion protection when long-term storage in damp medium.
1 tbl, 4 ex
FIELD: anticorrosive agents.
SUBSTANCE: invention relates to agents used against corrosion in energetic units cooling systems. The proposed anticorrosive addition agent comprises the following components, g/l: sodium silicate, 0.12-0.48; sodium tetraborate, 0.10-0.60; sodium nitrite, 0.18-0.50; sodium hexameta-phosphate, 0.20-0.80; sodium carbonate, 1.20-1.50. Invention provides enhancing the anticorrosive resistance of energetic unit cooling systems.
EFFECT: improved and valuable properties of addition agent.
4 tbl, 1 dwg
FIELD: corrosion protection.
SUBSTANCE: invention relates to anticorrosion compositions for metallic parts, in particular to utilization of MoO3 as agent enhancing anticorrosive properties of composition for anticorrosion coating based on dispersed metal, containing zinc of zinc alloy in aqueous phase (30-60% water in dispersion) and containing binding agent. Compositions for anticorrosion coating of metallic parts are disclosed containing such corrosion inhibitor (MoO3); at least one dispersed metal selected from group composed of zinc, aluminum, chromium, manganese, nickel, titanium, and alloys thereof; organic solvent; thickening agent; silane-based binder; optionally sodium, potassium, or lithium silicate; and water in amount from 30 to 60% by weight. Disclosed are also anticorrosion coating and metallic substrate with deposited anticorrosion coating prepared from above-defined composition.
EFFECT: improved resistance of composition to salt fog action.
22 cl, 2 dwg, 6 tbl, 3 ex
FIELD: anti-corrosive agents.
SUBSTANCE: invention relates to agents used in protection of metals against corrosion. Inhibitor comprises the following components, wt.-%: lanthanum oxide, 1.22-7.08; higher carboxylic acid triglycerides, 4.17-71.41; alkylbenzenesulfoacid (as measured for 100% of basic substance), 7.00-40.83; alkanolamine, 1.25-19.52; oxalic acid, 0.71-4.17, and organic solvent, the balance. Invention provides enhancing protective capacity in effect of aqueous medium in the presence of sodium chloride as an agent activating corrosion. Invention can be used in preparing oil-soluble inhibitors of sulfonate type being for anti-corrosive treatment of ferrous metals mainly.
EFFECT: improved and valuable properties of inhibitor.
6 cl, 2 tbl, 6 ex
FIELD: devices for protection against corrosion and deposition of salts, mainly scale, of water supply and water disposal systems.
SUBSTANCE: proposed composition contains the following components, mass-%: phosphoric acid (in terms of 100-% acid),0.01-74; calcium oxide or calcium hydroxide, or calcium carbonate or mixture of them (in terms of calcium oxide), 5-25; magnesium oxide or magnesium hydroxide, or magnesium carbonate, or mixture of them (in terms of magnesium oxide), 0.45-5; potassium hydroxide or potassium carbonate or mixture of them (in terms of potassium oxide), 0.01-5; silicon dioxide or water glass (in terms of silicon dioxide),0.2-2.2; sodium phosphates of common formula xNa2OyP2O5zH2O at molar ratio of (Na2O+H2O)/P2O5 from 1 to 3 (in terms of sodium oxide), 8-75; magnesium oxides of common formula MnxOy at molar ratio Mn/O from 1 to 2 (in terms of magnesium), 0.01-0.3.
EFFECT: enhanced ecological safety; improved anti-corrosion and anti-scale properties; improved quality of water due to deceleration of eutrophication process.
SUBSTANCE: method includes the setting of value of optimal dissolved oxygen concentration (KO2)pv from the minimum capacities in the limits of possible product concentration in the corrosion KFe under the maintenance of the electroconductivity values χ and рН of working area vapor-water area section, at the same the optimal value of (KO2)pv is established to χpp/χoc≤ 1.5, (рН)pv-(рН)op≤0.2 и (KFe)pp≤10 mkg/dm3, where χpp - the value of vapor electroconductivity after intermediate superheater, χос - the value of electroconductivity of cleaned turbine condensate, (рН)pv - рН nutrient water, (рН)op - рН of the direct steam, (KFe)pp - the concentration of corrosion in vapor after intermediate superheater.
EFFECT: optimal concentration of dissolved oxygen in nutrient water of power unit with steam - boiler of overcritical pressure provides the minimization of corrosion in the power unit water-vapor.
2 cl, 2 ex
SUBSTANCE: invention refers to metal protecting from corrosion and can be implemented in production of oil-soluble inhibitors of corrosion of ferrous metals of sulphonate type which are used as additives into motor oils, lubricating-cooling liquids and also as anticorrosion and conservation materials. Inhibitor contains, wt % lanthanum oxide 1.20-9.36; triglycerides of higher carboxylic acids 5.50-70.56; alkylbenzenesulphonic acid (as per 100% of basic substance) 9.92-53.94; alkanolamine 1.65-21.17; lanthanum salt 0.01-0.94; and organic solvent - the rest.
EFFECT: acceleration of process of composition preparing and also upgrading of protective property at water medium effect at presence of corrosion activator such as sodium chloride.
7 cl, 2 tbl