Cover to protect carbon steel from corrosion

 

(57) Abstract:

The invention relates to compositions for coatings for protection against corrosion upon contact of the steel with oil and oil products. The coating is produced by applying a mixture containing polyethylene, ash CHP, zeolite Tatar-Chartsalaska field, which improves corrosion resistance of the coating. Corrosion resistance of the coating is characterized by a corrosion rate that is 1.1-1.4 mm/year to 10-3. table 1.

The invention relates to compositions for protection against corrosion of carbon steel in contact with oils and petroleum products.

For corrosion protection of oil known polymeric adhesive tape made of polyvinyl chloride or polyethylene stabilized with soot, and bitumen-rubber or bitumen-polymer mastic reinforced with glass fiber (see C. G. Volkov, N. And.Tests Century. Century. Chobanov. Handbook for the protection of underground metal structures from corrosion. Leningrad, Nedra, 1975, S. 56).

The disadvantage of these materials is the difficulty of their application to the internal surface of pipelines.

Known materials used for coating the internal surfaces of pipelines. This SV is of Ayer. M, metallurgy, 1981, S. 515).

The disadvantage of these materials is the low corrosion resistance of the metal in contact with oils and petroleum products, especially rich in mineral salts and hydrogen sulfide, and cracking under the action of temperature factors.

Closest to the claimed is a plastic cover to protect carbon steel from corrosion received a dusting of powdered polyethylene on metal products, heated to a high temperature (see the Reference. The corrosion. Edited by L. L. of Schreyer. M, metallurgy, 1981, S. 526).

The disadvantage of this coating is insufficient corrosion protection of metal with the long-term contacting with oil products, rich in chloride and sulfide.

The invention is directed to improving the corrosion resistance of carbon steel, protected by plastic coating.

This is achieved in that the coating composition to protect carbon steel from corrosion-based composition containing polyethylene and optionally includes ash (waste CHP) and zeolite Tatar-Chartsalaska field in the following ratio of ingredients (wt.%): polyethylene 70-80, soliantu pre-milled and sifted through a sieve with apertures of 0.25 mm

Source components:

1) Polyethylene EN 03 277-73, GOST 16 388-85,

2) Ash - waste CHP must meet the following requirements:

a) bulk density of ash in the dry state should not exceed 1100 kg/m3b) moisture ash shall not exceed 20% by weight, in) content in the ash residue of unburned fuel, which is determined by the loss on ignition to 10000oC (GOST 9758-68) allowed in an amount not more than 20%, and during annealing up to 6000oC not more than 10%, g) content in the ash sulfate compounds in terms of SO3should not exceed 3% by weight (see Instructions for use evil power plants as fine aggregate claydite-concrete (Kuibyshev, 1975, 8 S.).

3) the Zeolite Tatar-Chartsalaska field of composition, wt.%: clinoptilolite 29-31, montmorillonite 23-25, cristobalite 14-16, mica 2-4, glauconite 2-2,4, ore minerals of 2.5-3.5: calcite 22-24 (see M, Artikis, M. M. Khaliullin, R. Z. Rakhimov. The influence of addition of zeolite-containing rocks on the properties of gypsum binders. Izvestiya vuzov construction, N 3, 1996, S. 8).

The mixture is applied in the usual way on the surface.

Example 1. Applying a plastic coating on the prototype.

The surface is poured into 10% hydrochloric acid at 200oC for 1 min, washed with distilled water and dried in air. The samples were heated to 1900oC, deposited powdered polyethylene and re-heated at 1900oC to melting stuck to the sample grains of polyethylene. The coating thickness was 1-1 .5 mm.

The corrosion resistance of the samples was determined according to OST 39-099-79 in solution composition, g/l: NaCl - 162,9, CaSO42H2O - 0,1, MgCl26H2O - 16,2, CaCl26H2O - 33,7, H2S - 0.1.

Testing the corrosion resistance of the samples was conducted gravimetric method over 108 days at 200oC. Before and after the test, the samples were weighed, and then, assuming that the corrosion products is the hydroxide of Fe(III), the increase in weight of the samples was counted on the underlying rate of corrosion (see N.P. The beetle. The course theory of corrosion and protection of metals. M, metallurgy, 1976, 472 C.). Each experimental point was determined as the arithmetical mean of the 10 samples. Last weight was determined after soaking the sample in a month in a desiccator under 200oC pulverized quick burned over calcium chloride.

Examples 2-8

The application of the plastic coating of the proposed structure.

Samples of steel St3, ST4, ST5, gotelli as well as described in example 1. The thickness of the coating in all cases was 1-1 .5 mm.

The compositions of the mixtures and the results of corrosion tests on different steels are given in table.

The table shows that the proposed by this invention, the composition increases the corrosion resistance of steel is more than 10 times.

Cover to protect carbon steel from corrosion based on polyethylene, characterized in that it additionally contains ash CHP and zeolite Tatar-Chartsalaska field, in the following ratios, wt.%:

Polyethylene - 70 - 80

Ash CHPP - 15 - 10

Zeolite - 15 - 10

 

Same patents:

The invention relates to the field of paint and varnish industry and can be used for applying coatings with antibacterial properties, metallic and non-metallic /concrete, brick and ceramic/ surface products and designs

The invention relates to construction materials and can be used in engineering industries for protection of metal from corrosion
The invention relates to corrosion protection and biocidal coatings designs used in the engineering, shipbuilding, pipeline construction and other areas where there is a risk of simultaneous corrosion and biodeterioration

The invention relates to a method of producing copolymers intended for the base sealing binders, anti-corrosion coatings, casting dimensionally stable compositions

The invention relates to methods of producing anti-corrosive epoxy thixotropic compositions without solvents for coating metal surfaces, for example, containers of oil fields

Floor coverings // 2143506
The invention relates to sheet materials suitable for use in coating for floors or floor coverings

The invention relates to sealing compositions used in coating and impregnating masses in the manufacture of roll roofing materials

The invention relates to construction materials and can be used in engineering industries for protection of metal from corrosion

The invention relates to the use of organic substances as components in bitumen compositions for the manufacture of sheet roll roofing and waterproofing materials used in construction

FIELD: cathodic protection of metalwork.

SUBSTANCE: proposed paint-and-varnish material for corrosion protection of metalwork includes electrically conducting film-forming agent (electrically conducting polyethylene) and carbon nanotubes, from 10 to 80% of volume of paint-and-varnish material which increase electric conductivity and resistance to aggressive media and consequently mechanical strength of metalwork. Proposed paint-and-varnish material may additionally contain high-dispersed zinc powder ensuring additional cathodic protection from 40 to 90% of volume of paint-and-varnish material.

EFFECT: enhanced efficiency of corrosion protection of metalwork during protracted period of operation due to smooth electrical potential equal to potential of metalwork being protected.

5 cl, 1 tbl

FIELD: chemistry; insulation.

SUBSTANCE: invention pertains to a cable with a coating layer, made from waste materials. The cable consists of at least, one conductor with at least one transfer element and at least one layer of coating. The coating material contains between 30 mass % and 90 mass % of the overal mass of the coating material, at least, first polyethylene with density not more than 0.940 g/cm3 and melt flow index from 0.05 g/10 min. to 2 g/10 min., measured at 190°C and a load of 2.16 kg in accordance with standard ASTM D1238-00, and quantity from 10 mass % to 70 mass % of the overall mass of the coating material, at least, second polyethylene with density of more than 0.940 g/cm3. The first polyethylene is obtained from waste material. Use of at least, one polyethylene with density of more than 0.940 g/cm3 in the recycled polyethylene allows for obtaining a layer of coating, capable of providing for mechanical characteristics, in particular, breaking stress and tensile strength, comparable to characteristics of primordial polyethylene. The stated coating layer is preferably used as an external protective coating.

EFFECT: obtaining of a new type of cable insulation.

43 cl, 9 dwg, 4 tbl, 10 ex

FIELD: chemistry.

SUBSTANCE: plastic composition with low viscosity, containing polyethylene with molecular mass of 1300-2700 - 100 pts.wt, and polyethylene with molecular mass of 1080-1250, or diesel fuel or engine oil instead of the latter - 10-20 pts. wt.

EFFECT: coating is water resistant, elastic, frost resistant, weather resistant and corrosion resistant.

2 tbl

FIELD: chemistry.

SUBSTANCE: composition with multimodal distribution of molecular weight has density between 0.94 and 0.95 g/cm3 at 23°C and melt flow index (MFI190/5) between 1.2-2.1 dg/min in accordance with ISO 1133. The composition contains 45-55 wt % low molecular weight homopolymer A of ethylene, 30-40 wt % high molecular weight copolymer B of ethylene and another olefin containing 4-8 carbon atoms, and 10-20 wt % ultrahigh molecular weight copolymer C of ethylene and another olefin containing 4-8 carbon atoms. The composition has high processibillity and resistance to mechanical loads and breaking, especially at temperatures below 0°C.

EFFECT: flawless coating for steel pips has mechanical strength properties combined with high hardness.

10 cl, 1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to tubes with a coating, having a high-mechanical strength layer of multimodal polyethylene. The tube has an inner surface, an outer surface layer (A) and a coating layer (B) covering said outer surface layer (A). The coating layer (B) contains a coating composition (B-2) which contains 80-100 wt % multimodal ethylene copolymer (B-1), having shear thinning index SHI2.7/210 from 10 to 100, where SHI2.7/210 is determined by shear frequency experiments in linear viscosity stress interval at frequencies from 0.05 to 300 rad/s according to ISO 6721-1 as a ratio of complex viscosity values η(2.7 kPa)/η(210 kPa), containing a multimodal ethylene copolymer (B-1), which is a copolymer of ethylene and one or more alpha-olefin comonomers, having 4-10 carbon atoms. The multimodal ethylene copolymer (B-1) also contains (B-1-1) 49-59 wt % low-molecular weight ethylene homopolymer component with respect to weight of the multimodal ethylene copolymer (B-1), wherein said component (B-1-1) has weight-average molecular weight from 5000 g/mol to 70000 g/mol and (B-1-2) from 51 to 41 wt % high-molecular weight ethylene copolymer component with respect to the weight of the multimodal ethylene copolymer (B-1), wherein said component (B-1-2) has weight-average molecular weight from 100000 g/mol to 700000 g/mol and the multimodal ethylene copolymer (B-1) has weight-average molecular weight from 70000 g/mol to 250000 g/mol and flow melt index MFR2, determined according to ISO 1133 at 190°C under a 2.16 kg load, from 0.05 g/10 min to 5 g/10 min, flow melt index MFR5, determined according to ISO 1133 at 190°C under a 5 kg load, from 0.5 g/10 min to 10 g/10 min, and density from 930 kg/m3 to 955 kg/m3; and ratio of weight-average molecular weight to number-average molecular weight Mw/Mn from 24 to 50. Said high-molecular weight ethylene copolymer component has weight-average molecular weight from 100000 g/mol to 700000 g/mol. The multimodal ethylene copolymer (B-1) has weight-average molecular weight from 70000 g/mol to 250000 g/mol and flow melt index MFR2, determined according to ISO 1133 at 190°C under a 2.16 kg load, from 0.05 g/10 min to 5 g/10 min, flow melt index MFR5, determined according to ISO 1133 at 190°C under a 5 kg load, from 0.5 g/10 min to 10 g/10 min, and density from 930 kg/m3 to 955 kg/m3, and ratio of weight-average molecular weight to number-average molecular weight Mw/Mn from 24 to 50.

EFFECT: coating can be applied on tubes with high output and cost-effectiveness; coating has good mechanical properties.

26 cl, 1 dwg, 2 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to tubes with a polymer coating and more specifically to coated metal tubes used at high temperatures. The tube has an inner surface, an outer surface layer (A) and a coating layer (B) covering said outer surface layer (A). The coating layer (B) contains a coating composition (B-2) which contains a multimodal ethylene copolymer (B-1) which is a copolymer of ethylene and one or more alpha-olefin comonomers with 6-10 carbon atoms. The multimodal ethylene copolymer (B-1) has weight-average molecular weight from 70000 g/mol to 250000 g/mol, and flow melt index STR2, determined according to ISO 1133 at 190°C and a 2.16 kg load, from 0.05 g/10 min to 5 g/10 min, flow melt index STR5, determined according to ISO 1133 at 190°C and a 5 kg load, from 0.5 g/10 min to 10 g/10 min. Density of said multimodal ethylene copolymer (B-1) ranges from 946 kg/m3 to 956 kg/m3. The coating composition (B-2) contains 80-100 wt % multimodal ethylene copolymer (B-1) with respect to total weight of the coating composition (B-2). The invention also relates to a method of making a coated tube. Coating composition (B-2) is deposited on a tube having an outer surface layer (A) to form a coating layer (B).

EFFECT: obtaining a coated tube, where the coating has high hardness, good properties at high temperatures and acceptable cracking properties under stress.

33 cl, 1 dwg, 2 tbl

Up!