Steel sheet with a coating and a method of manufacturing a steel sheet coated

 

(57) Abstract:

The invention relates to a steel sheet, in particular of stainless steel, suitable for the manufacture of the discharge element. Steel sheet contains, on at least one surface a protective coating resistant to delaminating at temperatures up to about 540oC. the Protective coating includes an inner inorganic part and the outer organic portion. The inorganic part of the coating has a density of not less than 50 mg/m2and represents converterhome coating based on chromium with a thickness of not more than 0.02 mm Converterhome floor contains solid particles of silicon oxide at a mass ratio of chromium to silicon dioxide of 1:1-1:2. The outer organic portion of the coating includes colorful silicone coating containing 40-60 wt.% silicone resin. Silicone colorful coating is dried at a temperature of less than 300oC for less than one minute and then it put a coating of thermoplastic acrylic copolymer, and a lubricating substance or of the polyolefin. The weight of the acrylic copolymer contains 5-70 wt.% lubricants and content of the polyolefin in the lubricant is 90%. Steel sheet with smutnoe 0,0005-0,020 mm, with a coefficient of friction of not more than about 0.05, and the density of the coating 10-5000 mg/m2. Dried colorful silicone coating with a lubricant coating is not sticky with moisture-, oil-, soil-repellent and similar properties. Steel sheet with a silicone coating can be easily formed in a discharge element with a minimum delaminating dried colorful silicone coating in the absence of the application to list additional external lubricant. The invention aims to improve the heat resistance and corrosion resistance in combination with good adhesion of the coating to the steel surface. 2 C. and 10 C.p. f-crystals.

The invention relates to a steel sheet, which can be used in the manufacture of heat-resistant elements for outlet structures, such as, for example, exhaust, exhaust devices for exhaust gases. On a sheet of pre-applied protective coating consisting of an inner inorganic part and the outer organic portion covered with a dry film lubricant. The inorganic part of the coating dried formed on the sheet, i.e. at the place, convertible coating based on chromic acid containing solids, and organic casalinuovo thermoplastic and grease or polyolefin. Sheet with a pre-applied coating can be formed in the element and is welded in the absence of the need for the application to the steel sheet before forming additional external lubrication.

Unlike steel cold rolling is very difficult to achieve good adhesion of the coating of paint for stainless chromium steel, such as stainless steel. The obvious reason for the poor wettability of the surface of the stainless steel paint is present on the surface of such steel passivated oxide. To improve the adhesion of the paint layer by removing this oxide passivated use different types of acid etching agents. However, this method does not lead to good adhesion colorful coating to stainless steel, especially, are molded in different elements exposed to high temperatures and wet corrosion.

In other cases, experts proposed methods one - or two-stage leaching of stainless steel in an acid bath containing hexavalent chromium and the silane agent combinations, before applying the coating of paint. For example, after immersion in chromic acid steel subjected to etching, washed with water army dispersion of silicate and silane. Despite the possibility of achieving good adhesion, a significant drawback of such methods using acid chromium are the costs for the disposal of waste solutions containing hazardous hexavalent chromium.

On steel surfaces subjected to cyclic heat treatment in a corrosive environment, put colorful coating on the basis of various heat-resistant organic resins. Such surfaces include boilers, blast furnaces, space heaters, furnaces, exhaust pipes, engines, mufflers and the like. Polyfunctional organic resin, cured in the process of chemical reactions, can exhibit a high thermal stability due to the high density crosslinked state. Curable resin, such as epoxy, and phenolic Novolac have moderate temperature resistance up to 260oC.

Due to the high degree of crosslinking with polyfunctional wilanowie groups of the resin-based organofunctional silicones such, kaxilaxi, have a high temperature resistance and high resistance to oxidation. Accordingly, silicones known as one of the most heat-resistant resins used at elevated temperatures and is widely used for the mi. Typical colorful heat-resistant composition comprises a silicone resin, one or more pigments, hydrocarbon solvent, a filler, such as mica, magnesium silicate, aluminum silicate and a crosslinking catalyst, such as, for example, octant iron, zinc naphthenate. The system is based on modified organic silicone resin comprising 15-20% silicone, can have heat resistance up to about 204oC. System based on an organically modified silicone resin containing 51-90% silicone, can have improved heat resistance up to about 370oC. System based on an organically modified silicone resin containing 51-90% silicone and soot, can have heat resistance up to about 427oC. this Is the General principle. When using the appropriate modifiers organically modified resin may have a resistance exceeding 427oC. System containing 100% silicone resin and carbon black, may have increased thermal stability up to about 538oC. System containing 100% silicone and ceramic pigment, may have a heat resistance up to about 760oC.

Know the application of heat-resistant paint coatings on the basis of the internal combustion. Such dyes are commercially available under various conventional names, such as paint, muffler, heat resistant coatings, heat resistant paint and coatings for wastewater systems. Heat resistant paints such a purpose can be prepared on the basis of modified silicones, organic resins or organically modified silicone resin. For example, U.S. patent US 5021489 refers to the anti-corrosion coating for steel containing 10-35 wt.h. silicone resin, 2-35 including siliconalley resin, 10-35 including acrylic resin, 0.5 to 5 hours of organic phosphate, 1.0 to 10 o'clock sulfonate metal, 5-40 including low molecular weight aliphatic alcohol and 10-50 hours of an organic solvent.

U.S. patent US 4702968 refers to aluminized steel, pre-treated with a solution of chromate coated with a primary coating on the basis of polyamide resin containing strontium chromate, and an external coating based on modified silicone polyester containing soot. Chromate coating layer contains 10-50 mg/m2chromium. The primary coating has a thickness of 3-8 μm, and the outer coating has a thickness of 8-20 μm. Polyester layer contains 30-50% modifier polysiloxane oligomer containing 3-12 and astonomy coverage for the discharge muffler stainless steel contains colorful coating based on silicone resin. Colorful floor contains 78-93 wt.% silicone resin, 3-8 wt.% butylmalonate, 1-5 wt.% talc and 3-8 wt.% synthetic mica. Colorful coating is dried and utverjdayut at temperatures above 1000oC.

In the application JP 07-053723 describes a heat-resistant coating for discharge silencers containing a silicone resin, a modified polyester. Silicone resin modified by mixing a polyester resin containing at least two hydroxyl groups, with dimethylpolysiloxane with reactive terminal groups by hydrolysis and polycondensation of the mixture in the presence of a catalyst.

In the application JP 63-021314 describes how to prevent corrosion in the time of the muffler. The silencer is made of steel with metal coating, pre-treated with a chromate solution, and then applied a coating of an organically modified silicone resin. When heated muffler organic part of the silicone resin is decomposed with the formation of a surface protective film.

In the case of manufacturing a steel sheet with colorful coating of such organic ink composition in processincoming in the process of forming/stamping sheet in the manufacture of the discharge element. The reason for this is the inadequate adhesion of the coating of paint to the molded element. In addition, formed on the driving formed flaking paint.

Due to such poor adhesion of the steel sheet cannot usually be covered utverzhdenii colorful composition based on organic silicone before molding or stamping.

The problem could not be practically solved by applying colorful silicone coating on the steel sheet without curing the paint layer before manufacture of the discharge element due to the fact that the uncured silicone coating is very sticky. With the collapse of the steel sheet with the uncured coating to the coil in the future when you try to deploy coils for the manufacture of the element coils of the coil tend to stick together with each other.

Accordingly, at present the discharge elements applied layer of paint spraying after their manufacture. The application of the coating of paint onto structural elements carry out, mainly for cosmetic reasons, i.e. their appearance. When spraying the percentage applied to the paint surface is usually 40-70% of the species. In addition, in the case where the discharge element is the silencer of the car, this colorful floor often pulls away from the muffler less than one year.

As evidenced by the many previous attempts specialists, already long overdue in the creation of heat-resistant steel, especially stainless chromium steel, is suitable for forming the discharge elements and having a colorful coating with high heat resistance and resistance to wet corrosion in combination with enhanced adhesion to the steel surface. Especially there is a need for chromium alloyed steel sheet with such a colorful coating with high adhesion during forming of the steel sheet in the discharge element. The technological process of production of such alloyed chromium steel sheet with colorful coating must be inexpensive, and it uses colorful material should not be toxic to the environment so that they can be safely disposed of.

The essence of the invention.

The present invention relates to a steel sheet, such as, for example, from legirovannoi chromium steel having, at least on the/SUP>C. the Protective coating includes an inner inorganic part and the outer organic portion, and the organic portion includes covering the top of the dried polymer film lubrication. The inorganic portion of the cover includes converterhome coating based on chromium containing solid particles. The organic portion of the coating contains dried, organic paint coating containing at least 20 wt.% the silicone. The dried film of grease covers the surface with a silicone coating and is a thermoplastic acrylic copolymer, the weight of which contains 5-70 wt.% lubricants, or it contains at least 90% of the polyolefin. Steel sheet with the coating is dry, non-sticky, water-resistant, has oil, graziottin nodding and similar properties, can be easily molded into the product and may be welded in heat-resistant steel element with a minimum delaminating dried silicone coating in the absence of the need for additional external lubrication of the surface of the steel sheet. Silicone colorful coating cures in the process of operation of heat-resistant element.

Another feature of the heat-resistant element is above statalyzer, pigment, filler and the inhibitor.

Another feature of the invention is the above-mentioned dried silicone coating, having a thickness of 0.005 to 0.05 mm

Another feature of the invention is the above-mentioned dry film having a thickness of 0.02 mm

The next feature of the invention is the above-mentioned dry film density of the coating 10-5000 mg/m2.

Another feature of the invention is a dry-film coefficient of friction of not more than about 0.05.

Another feature of the invention is the above-mentioned converterhome floor with a mass ratio of chromium and solid particles in the range from 1:1 to 2:1.

The next feature of the invention is the above-mentioned converterhome floor with a density of not less than 50 mg/m2.

Another feature of the invention is the above-mentioned converterhome floor with a density of 100-500 mg/m2and a thickness of 0.02 mm

Another feature of the invention is the above-mentioned particle size of 0.001 to 0.2 μm, which represents a silicon oxide or titanium oxide.

Another feature of the invention is the above-mentioned sheet of stainless chromium steel.

The present invention relates t is s, at least one surface of the steel sheet of fluid on the basis of chromic acid containing solid particles. The sheet is dried for education on one surface of a convertible coverage. Surface with convertible plated then coated with silicone resin emulsion paint containing at least 50 wt. % solids, not less than 20 wt.% which is a silicone resin. Sheet with a silicone coating is then heated to elevated temperature for a time sufficient for drying silicone coating. Thereafter, the sheet with the dried silicone coating is covered with an aqueous suspension containing 10-60% (based on solid polymer lubricant. Polymeric lubricant may be a thermoplastic acrylic copolymer and a lubricant or a polyolefin. The weight of the acrylic copolymer contains 5-70 wt. % lubricants. The polyolefin contains 90% of the olefin. The surface is coated with a polymer lubricant is heated to elevated temperature for a time sufficient for the formation of dry, not sticky film having moisture-, oil-, soil-repellent and similar properties, capable of molding products and welding with the formation of heat-resistant steel and the necessity of applying to one surface lubrication. Silicone colorful coating cures in the process of operation of heat-resistant element.

Another feature of the invention is the above-mentioned sheet with a silicone coating, dried at a peak metal temperature of at least 300oC.

Another feature of the invention is the above-mentioned sheet with a silicone coating, dried at a peak metal temperature of at least 250oC for 1 min.

The next feature of the invention is the above-mentioned converterhome floor with a mass ratio of chromium and silicon dioxide in the range from 1:1 to 2: 1.

Another feature of the invention is the above-mentioned converterhome coating density on one surface of at least 50 mg/m2.

Another feature of the invention is the above-mentioned converterhome coating containing not more than 15 wt.% hexavalent chromium.

Another feature of the invention is the above-mentioned sheet, coated with grease heated to a peak metal temperatures 25-120oFor curing polymeric lubricant.

The principal technical problem of the invention to provide a flat steel plate with colorful coating capable of formularizing resistance.

Another technical task of the invention to provide a discharge element of the alloyed chromium steel with colorful coating having superior high temperature resistance and corrosion resistance.

Another technical task of the invention to provide a discharge element from stainless chromium steel with colorful coating, heat resistant at temperatures up to 540oC.

Another technical task of the invention to provide a flat sheet of stainless chromium steel, capable of forming in the discharge element without deposition of paint on shaped driving.

Following the technical task of the invention to provide a steel sheet with colorful coating without the use of such materials for coating and without the formation of such by-products of waste materials used for coatings that are toxic to the environment.

Another technical task of the invention to provide a steel sheet with colorful coating with water-, oil-, soil-repellent and similar properties, capable of collapsing after molding a heat-resistant element.

An important advantage is not fully crosslinked, while the folding of the sheet into a coil is not observed clumping of turns of the sheet to each other.

An equally important advantage of the present invention is the possibility of forming a heat-resistant element from a flat steel sheet having a soft but not sticky layer of paint. Another advantage of the present invention is the ability of the welding element, formed of a steel sheet that has dried fully stitched colorful coating, which does not form volatile products uncured paint. Another advantage of the present invention is to achieve high adhesion colorful cover for stainless chromium steel without using or receiving harmful substances that cause problems for disposal. Another advantage is no need for additional costly lubrication flat steel sheet before forming from it diverting element, which creates problems in providing safety in the workplace, reducing the cost of production and the receiving sheet of stainless chromium steel with high durability and resistance.

Another advantage of the present invention is in the ü cleaning and low complexity of the process.

Information confirming the possibility of carrying out the invention

The present invention relates to heat-resistant steel sheet having a protective inorganic/organic coating and the method of its production. The protective coating is dry, not sticky with moisture-, oil-, soil-repellent and similar properties. The coated sheet can be easily formed with a minimum delaminating protective coating and has the capacity for subsequent welding without volatilization of the protective coating. There is no need for applying more lubricant on the sheet before forming.

Under heat-resistant steel sheet should be same steel sheet capable of forming the element exposed to high temperature conditions up to about 540oWith, in particular, the effects of cyclic temperature conditions, including corrosive atmosphere. Without purpose, limitations, examples of the element include the exhaust pipe of the engine, mufflers engines, catalytic converters, boilers, furnaces, blast furnaces, cremation ovens and grills, operated out of the premises.

The term "sheet" includes annoy chromium steel, having at least on one of its surface with a protective coating resistant to delaminating or delamination at temperatures up to about 540oS, consisting of the internal inorganic part and the outer organic portion, and the organic portion includes top dry film. Internal inorganic part consists on one surface of at least 50 mg/m2dried "on the spot" ("driede-in-place") convertible coatings based on acid hexavalent chromium containing solid particles when the mass ratio of chromium and particulate solids within, respectively, from 1:1 to 2:1. Solid particles are a very important characteristic of the invention, because they give a high resistance converterhome the floor, resulting in a colorful coating remains firmly connected to the discharge element even at very high operating temperatures up to about 540oC. External organic part consists of the dried silicone paint coat containing not less than 20 wt. %, preferably at least 30 wt.%, even more preferably, at least 40 wt.%, and preferably, 40-60 wt.% silicone resin. The organic portion of the coating is tereasa 10-60% (based on solid polymer lubricant. Polymeric lubricant may be a thermoplastic acrylic copolymer with grease or polyolefin. In that case, if the lubricant is an acrylic copolymer, the weight of the copolymer contains 5-70 wt.% the lubricant. If grease is a polyolefin, its content in the film of lubricant is not less than 90%. The density of the coating on one surface must be not less than 10 mg/m2.

The protective coating may be formed at least on one surface of a sheet of stainless chromium steel using the colloidal suspensions on the basis of acid hexavalent chromium containing solid particles when the mass ratio of chromium and solid particles within, respectively, from 1:1 to 2:1. One of the surfaces includes a continuous uniform coating, so that the density convertible coating after drying, the sheet is not less than 50 mg/m2. Preferably, converterhome coating has a thickness of not more than about 0.01 mm and a density of not less than 100 mg/m2more preferably, about 150-250 mg/m2. Density convertible coating should not exceed about 500 mg/m2and its thickness is not more than about 0.02 mm, and since the key to the surface with an inorganic coating is applied silicone colorful floor. Then the sheet is heated at an elevated temperature for a time sufficient for drying silicone colorful cover. On the surface with an organic silicone coating then apply a continuous coating of an aqueous suspension containing 10-60% (based on solid polymer lubricant. Polymeric lubricant may be a thermoplastic acrylic copolymer with the lubricant or polyolefin. The weight of the acrylic copolymer contains 5-70 wt. % lubricants. Grease-based polyolefin contains at least 90% of the polyolefin resin. The sheet is heated at elevated temperatures for the time necessary for the formation of silicone colorful top floor dry not sticky film of grease.

The colloidal suspension includes hexavalent chromium (CR) and trivalent chromium (CR), using solid particles with high heat resistance, which leads to the formation on the surface of the steel sheet silicone coating and its adhesion to the steel surface. The coating on the basis of chromic acid according to the invention is drying on site (dry-in-place) convertible coating. It is drying on the spot converterhome floor is an important feature of this image is chromic acid, drying at the place of the coating does not form toxic by-products of waste. Another purpose of the use of drying on the site of a convertible cover is the provision of oxidation and conversion to chromate coating on the surface of the steel sheet. It's also essential to achieve a continuous and uniform coating of the entire surface of the sheet with sufficient thickness of the chromate layer to ensure good adhesion of the external protective organic layer to the surface of the steel sheet.

Another important aspect of the invention is the inclusion in converterhome coating of solid particles, which not only have high heat resistance, which provides a strong connection colorful cover with a discharge element even at very high temperatures, up to about 540oWith, in terms of its operation, but which also have a size less than 0.2 microns. Solid particles function as a carrier for hexavalent chromium ions, allowing attain a good distribution in colloidal suspensions. The suspension ions of chromium is in the process of adsorption/absorption on the surface of small particles. Suitable solid particles satisfying such requirements is pyrogenic silicon oxide, having a particle size of about 0.01-0.0 theme and have a tendency to sedimentation. On the contrary, particles much smaller than 0,001 μm is not desirable because they, essentially, are the ions and tend to dissolve in the suspension. Suitable solid particles include silicon oxide (SiOx) and titanium oxide (TiOx), and silicon oxide is preferred.

Organic part of the protective coating according to the invention is formed from a water-based paints or organic solvent containing an organic silicone resin, to form a dry protective coating heat-resistant up to a temperature of about 540oC. Liquid paint contains at least 50 wt.% solids, and solid colors, i.e., dry paint contains at least 20 wt. % silicone resin. Preferably, the solid ink contains at least 30 wt.% silicone resin, more preferably at least 40 wt.% silicone resin, and most preferably 40-60 wt.% silicone resin. Volatile organic content silicone resin emulsion paint, preferably, is not more than 0.42 kg/l, the term "silicone resin" refers to a silicone resin having a basic skeleton chain (Si-O-Si)n, formed organopolysiloxane the oligomer containing 3-12 atoms of Si and 2-4 SUB> such as methyl, phenyl, were, diphenyl and the like. Phenyl organic group is preferred because it provides high temperature resistance and oxidation resistance, and good viability silicone resin. Methyl organic group is desirable because it provides good hardness when heated, flexibility, good chemical-resistant and resistant to thermal shock. Without intent to limit some examples of silicone resins, i.e., siloxanes, are dimethylsiloxane, polymethylsiloxane and polymethylphenylsiloxane. The term "silicone resin" also includes a silicone resin, a modified organically interaction with other resins. Suitable for modifying the silicone resin organic resins include alkyd resins, phenolic resins, epoxy, epoxy-ether, polyurethane, acrylic and polyester. Modified silicones according to the invention can have a molecular weight of about 5000-20000 and can contain other associated skeletal chain end groups, such as methylphenylene, diphenylene, hydroxyl. Such end groups promote cross-linking of the coating of paint. Modified strong sheet, covered with silicone paint. Stitching colorful coating is in the process of operation are molded of heat-resistant element. Modified silicone resin improves the adhesion of the coating of paint to the steel sheet during forming/stamping sheet a heat-resistant element without stitching.

Preferably, the silicone resin is soluble in the liquid medium (solvent) such as xylene or toluene to form a paint. This paint can contain one or more catalyst, pigment, filler and the inhibitor. A suitable catalyst is octant iron. Suitable pigments for the paint is metallic fillers iron oxide, magnesium oxide, carbon black, graphite, silicon oxide, silicon mica, aluminum, aluminum silicate, magnesium silicate and the like. Suitable fillers are mica nepheline syenite. Suitable inhibitors are zinc phosphate and chromate. Suitable silicone resins for purposes of the present invention are supplied by Dow Corning Corporation of Midland, Michigan 48686.

Such silicone organic dye is applied to the steel sheet with chromate convertible coating with the thickness of the outer silicone pokr what about the coating should not exceed about 0.05 mm due to the possibility of delaminated coating in forming the steel sheet in the item. In addition, increasing the duration of the drying process to more than one minute, which will require several stages of drying in a continuous process of coating steel sheet.

Heat-resistant silicone colorful floor utverjdayut at temperatures of at least about 235oC for about 30 minutes Colourful coating based on modified silicone utverjdayut at a temperature of approximately 200oC for about 20 minutes Curing such inks, printed on the flat steel sheet, causes embrittlement of the paint. Forming a steel sheet coated with utverzhdenii paint, causing delamination or delaminated paint covering. In the framework of this invention it was found that on a flat steel sheet can be applied uncured silicone colorful coating, which is not sticky in that case, if the uncured colorful coated film of dry lubricant. One of the significant advantages of using the dry film lubricant is that a steel sheet with a continuous coating of dry, but uncured silicone paint can be rolled into a coil, and there is no clumping of individual coils with each other when connecting the opening, which otherwise would be sticky and would cause coalescence of the individual turns of the coil to each other. Another significant advantage of using a dry film lubricant is the possibility of applying to the steel sheet by continuous method of heat-resistant dry paint covering and forming it into an item without delaminated or loss of adhesion of the paint coat. In the process of drying the steel sheet with colorful silicone coating in less than one minute at a peak metal temperature less than 300oWith, preferably, less than 250oC, more preferably less than 220oIs curing the coating of paint, resulting in a layer of paint remains, essentially, soft and ductile, hence the lack of delaminated during molding. The dry film lubricant provides a sufficient lubricating effect, and colorful coating remains firmly connected to the surface of the steel sheet in the process of molding a heat-resistant element. Under the "drying" colorful silicone coating imply drying, which reach a minimum degree of crosslinking the coating of paint before forming heat-resistant steel element. Silicone beauty is edocfile, drying time colorful silicone coating at a peak metal temperature is not less than 20 in order to avoid difficulties during the welding process. Such difficulties when welding associated with the uncured silicone colorful coating according to the invention includes excessive formation of volatile products during welding, for example laser welding of heat-resistant element, formed of a steel sheet, and the deposition on the electrodes during the process of gas tungsten arc welding. When drying colorful silicone cover for 20-60 s at peak metal temperature is the minimum curing, resulting in eliminating excessive formation of volatile products during welding. Full curing of the coating of paint on shaped steel element happen "in city" in the process of operation of the element.

Another important aspect of the invention is the application of protective paint coat a thin film of dry not sticky polymer lubricant. Polymeric lubricant preferably is an acrylate resin and includes a lubricating substance, such as described in U.S. patent US 4942193 provided here as a reference. A thin film of a polymeric lubricant or weight of the copolymer together with the lubricant, preferably 10-30 wt.%. The acrylic copolymer is a neutralized polymer with acidic or basic functional groups, obtained by polymerization in the solvent environment Ethylenediamine monomers. The acrylic copolymer may contain about 10-40 wt.% of monomer units with acid functional groups. Examples of such monomers are acrylic acid, methacrylic acid, crotonic acid, taconova acid and maleic acid. The acrylic copolymer may also contain 5-20 wt.% of monomer units with the basic functional groups. Examples of such monomers are aminoethyl(meth)acrylate, tert-butyl-amino-ethyl(meth)acrylate and diisobutylamine(meth)acrylate. The lubricant may be a wax such as polyethylene wax, petrolatum wax, beeswax, Carnauba wax, polyolefin wax, and mixtures thereof. In addition, a lubricating substance may include one or more additives, silicone fluids, molybdenum disulfide, graphite, hydrocarbon or vegetable oil. On silicon coated with a thin coating layer of an aqueous suspension containing acrylic copolymer, and a lubricating substance, and utverjdayut at a temperature within asiausa film. Is essential that the weight of dry lubricant should be sufficient to avoid the need to apply additional lubricant to the colorful silicone coating before forming a flat steel sheet in the discharge element. Accordingly, the dry lubricant should be present on one surface of at least 10 mg/m2preferably, at least 100 mg/m2more preferably 200-300 mg/m2and preferably not more than 500 mg/m2. The content of the dry bundles should not exceed 5000 mg/m2because it can flake off, leaving the balance made driving the molded element of a steel sheet, which will require frequent stops continuous process and cleansing. The dry lubricant film should have a thickness not less than about 0,0005 mm, but more than approximately 0.020 mm. Preferably, the film thickness dry film lubricant shall be not less than 0,002 mm, more preferably not less than 0.005 mm and, preferably, about 0,010 mm

In the case where the lubricating coating formed from an aqueous suspension containing acrylic resin, the resin must be cured in the presence of lubricants for education necessary lubrication n from aqueous suspensions containing polyolefin resin, for example, polyolefin wax, polyolefin powder, there is no need for the introduction of aqueous suspension of additional lubricants. Polyolefin film has a lubricating effect that is similar to the acrylic copolymer. It should be clear that the polyolefin resin may include products copolymerization of olefins with other comonomers, for example a copolymer of olefin and acrylic acid. Olefinic lubricant can be formed from a liquid composition water-based or solvent containing a dispersion of a powder of polyolefin wax.

Converterhome silicone coating and lubrication can only be applied to one or both sides of a sheet of stainless chromium steel on conventional equipment, such as roll, reversionary roll, squeezing roll or an air knife. Preferably, the steel sheet coated with the continuous method for reversioner roll. The roll is preferred from the point of view of completeness of continuous coverage across the entire sheet width and the uniformity of the thickness of the coating layers coating/film lubrication. In the case where a dry lubricant is of sufficient density and thickness and completely covers the steel sheet, the flat sheet or molded running directly before forming the discharge element. In the case of regulation, the minimum density of the dry film lubrication, the friction coefficient of the steel sheet is set to <0,05. On the other hand, the density of the lubricating coating is more than about 5000 mg/m2is undesirable due to the exfoliation of the lubricant, resulting in damage to the underlying layer of paint covering and deposits being formed on the driving. The sheet of liquid coating can be dried after each of the three stages coating conventional drying equipment such as a convection oven or an induction heater.

The invention is illustrated in the following examples.

Example 1.

One surface of the flat panel stainless steel cold rolling is subjected to annealing and etching, brand 409, thickness 1 mm, width of 10 cm and a length of 15 cm purify alkali and subjected to blasting treatment to make the surface Shine (scotch bright surface treatment). On one surface of the four treated panels in laboratory conditions on rolls put colorful silicone coating, pigmented soot of different thicknesses. After heating the stainless steel panels to a peak metal temperatures 200oWith and exposure in the silicon layer of paint is dry, but sticky. These flat panels are then tested for corrosion resistance according to the specification of General Motors (GM) 9985384. The test involves heating the sample to 450oWith a sharp cooling water to 2oC. This procedure is repeated 10 times before sticking panels with colorful coating in an atmosphere of salt vapors for 168 hours and Then visually evaluate the appearance of flat panels. A score of 9 indicates the presence of slight traces of corrosion and a rating of 7 indicates a poor corrosion and is unacceptable. It is believed that the sample can withstand the test of GM, if its score corresponds to at least 9.

Example 2.

In this example, two additional flat panel stainless steel cold rolling is subjected to annealing and etching, brand 409 cleaned and put on them the paintwork as described in example 1. However, in this case, before applying the coating of paint on the cleaned panel pre-applied converterhome chromate coating, dried on site ("dry-in-place"), containing solid particles of silicon oxide, followed by the application of silicone colorful coating thickness of 0.02 mm Converterhome chromate coating containing solid oxide particles kreeri density of the coating 161 mg/m2. This colorful floor comes BetzDearbon, Metals Process Group, Morsham, Pennsylvania, 19044, under the trade name Permatreat 1500. The flat panels are tested for corrosion resistance and evaluated as described in example 1. Visual evaluation of the corrosion resistance of these panels above and consistent with 9 and 8. A rating of 8 indicates a weak corrosion. These examples show that to withstand the test sample according to GM specifications with rating not less than 8 enough to use even a thin layer of paint covering.

Example 3.

This example illustrates the present invention. Two additional panels of example 2 after the preliminary application of a convertible chromate coating and colorful silicone coating on rollers coated water suspension containing the lubricant of the acrylic copolymer. Water suspension comes PPG Industries, Allison Park, Pennsylvania, under the trademark CHEMFORM TK4. After drying to a thickness of 0.02 mm on a sticky silicone paint coat is applied acrylic copolymer. Then the panel is dried at 110oWith over 35 for the formation of dry, non sticky lubricant with a density of 2500 mg/m2. Visual evaluation of appearance when tested for corrosion stokoe and external organic protective coating of dry acrylic lubricants, for these panels was increased to 10 and 9. A score of 10 indicates no visual signs of corrosion.

Example 4.

This example also illustrates the invention. Two flat panels of example 2 and two flat panels of example 3 formed into bowls swift (Swift Cups). Flat panels from example 3 were coated according to the invention. After molding bowls produce a visual assessment colorful silicone coating. Bowl, formed from flat panels that do not have dry lubricant (example 2), are cracks in the paint layer in the bends of the bowls. Such molded cups then tested for corrosion resistance according to GM specifications 9985384 as described in example 1. After this bowl is kept in the atmosphere of salt vapors for 168 hours and Then visually evaluate the appearance of molded items. The bowl formed of two panels, which are coated according to example 2, do not pass the test for corrosion resistance and have a visual assessment only 7. The bowl formed of two panels having a coating according to example 3, can easily withstand test for corrosion resistance and have a visual assessment 9.

The test results in example 4 clearly demonstrate significant is asonog coverage, which caused dry lubricant, and the importance of forming such a flat steel sheet in the element while maintaining the strong coupling of the dry silicone colorful coating element in the molding process. The presence of dry acrylic grease on the uncured silicone colorful coating provides molded cups swift without delaminated and cracking uncured silicone paint covering.

Example 5.

This example also illustrates the invention. On a flat stainless steel panels T 409 size 61 x 61 cm coated as described in example 3, and is then formed from them silencers. After Assembly using laser welding these silencers tested according to the specification of General Motors 9984299. While mufflers heated to 450oC and then cooled rapidly in ice water to 2oC. the Procedure was repeated 5 times. Then the mufflers stand in the atmosphere of salt vapors within 168 hours All formed mufflers stand the test of GM. Thanks drying panels with silicone coating at peak metal temperature equal to 200oWith, for at least 20 does not escape the uncured silicone colorful coating is of without derogating from its nature and scope. Therefore, the scope of the invention should be defined in the following claims.

1. Steel sheet with a coating for the manufacture of heat-resistant element, characterized in that at least one surface of the steel sheet provided with a resistant delaminating at temperatures up to about 540oWith a protective coating comprising an inner inorganic part and the outer organic portion comprising a dry film, and the internal inorganic part consists converterhome coating based on chromium containing solid particles, the outer organic portion includes colorful silicone coating containing at least 20 wt. % silicone resin, and a dry film made of a thermoplastic acrylic copolymer, and a lubricating substance in the content of the lubricant of 5-70% by weight of a copolymer or a polyolefin when the content of the polyolefin is not less than 90%, and the dry film is not sticky and has a water-, oil - and soil-repellent properties, and steel coated sheet can easily be molded into a heat-resistant element with a minimum delaminating colorful silicone coating and the lack of need application to list additional unease has a density of 50-500 mg/m2.

3. Steel sheet under item 1, characterized in that the mass ratio of chromium and solid particles in the converted coverage is 1: 1-1: 2.

4. Steel sheet under item 1, characterized in that the solid particles have a size of 0.001-0.2 μm.

5. Steel sheet under item 1, characterized in that converterhome coating has a thickness of not more than 0.02 mm

6. Steel sheet under item 1, characterized in that colorful silicone coating contains at least 30 wt. % silicone resin and has a thickness of 0.005-0,050 mm

7. Steel sheet under item 1, characterized in that the dry film has a thickness of not less than 0,0005 mm

8. Steel sheet under item 1, characterized in that the dry film has a density of not less than 10 mg/m2.

9. Steel sheet under item 1, characterized in that the dry film has a coefficient of friction of not more than about 0.05.

10. A method of manufacturing a steel sheet with a coating suitable for the manufacture of heat-resistant element, comprising applying, on at least one surface of the steel sheet of liquid coating based on chromic acid containing solid particles, drying the sheet for formation on the surface of a convertible coatings, applied on the surface is the Eney 50 wt. % solids, consisting of not less than 20 wt. % of silicone resin, heating the steel sheet coated with colorful coating at peak metal temperature for a time sufficient for drying silicone paints, drawing on the dried silicone colorful floor continuous aqueous slurry containing 10-60% (based on solid polymer lubricant consisting of acrylic copolymer, and a lubricating substance in the content of the lubricant of 5-70% by weight of the copolymer or of the polyolefin when the content of the polyolefin is not less than 90%, and heating the steel sheet coated with a lubricating coating with a peak metal temperature in the course of time, sufficient to education is not sticky dry film lubrication with water-, oil - and soil-repellent properties, obtaining a steel sheet with a coating that can easily be molded into a heat-resistant element with a minimum delaminating colorful silicone coating in the absence of the need for the application on this one surface lubrication.

11. The method according to p. 10, characterized in that the steel sheet coated with colorful silicone coating is heated at t the th sheet coated with a lubricating coating is heated at a temperature of about 65-110oC.

 

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