PT88371B - PROCESS FOR THE TREATMENT OF LAMINATED ACID TO INCREASE CORROSION RESISTANCE - Google Patents
PROCESS FOR THE TREATMENT OF LAMINATED ACID TO INCREASE CORROSION RESISTANCE Download PDFInfo
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- PT88371B PT88371B PT88371A PT8837188A PT88371B PT 88371 B PT88371 B PT 88371B PT 88371 A PT88371 A PT 88371A PT 8837188 A PT8837188 A PT 8837188A PT 88371 B PT88371 B PT 88371B
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- Prior art keywords
- coating
- rolled steel
- steel
- process according
- water
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Links
- 238000000034 method Methods 0.000 title claims abstract description 25
- 238000011282 treatment Methods 0.000 title claims abstract description 15
- 238000005260 corrosion Methods 0.000 title claims abstract description 8
- 230000007797 corrosion Effects 0.000 title claims abstract description 8
- 239000002253 acid Substances 0.000 title description 2
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 46
- 239000010959 steel Substances 0.000 claims abstract description 46
- 238000000576 coating method Methods 0.000 claims abstract description 28
- 238000005096 rolling process Methods 0.000 claims abstract description 27
- 239000011248 coating agent Substances 0.000 claims abstract description 26
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 23
- 238000001816 cooling Methods 0.000 claims abstract description 16
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims abstract description 14
- 229910052751 metal Inorganic materials 0.000 claims abstract description 12
- 239000002184 metal Substances 0.000 claims abstract description 12
- 229910052725 zinc Inorganic materials 0.000 claims abstract description 12
- 239000011701 zinc Substances 0.000 claims abstract description 12
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 10
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 claims abstract description 6
- 239000004567 concrete Substances 0.000 claims description 12
- 238000005554 pickling Methods 0.000 claims description 9
- 230000002093 peripheral effect Effects 0.000 claims description 7
- 229910000576 Laminated steel Inorganic materials 0.000 claims description 3
- 229910001563 bainite Inorganic materials 0.000 claims description 3
- 229910000734 martensite Inorganic materials 0.000 claims description 3
- 239000003822 epoxy resin Substances 0.000 claims description 2
- 229920000647 polyepoxide Polymers 0.000 claims description 2
- 239000000843 powder Substances 0.000 claims description 2
- 238000005507 spraying Methods 0.000 claims description 2
- 229920003002 synthetic resin Polymers 0.000 claims description 2
- 239000000057 synthetic resin Substances 0.000 claims description 2
- 238000005496 tempering Methods 0.000 claims description 2
- 230000000717 retained effect Effects 0.000 claims 1
- 210000002268 wool Anatomy 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 abstract description 3
- -1 for example Substances 0.000 abstract description 2
- 239000007795 chemical reaction product Substances 0.000 abstract 1
- 239000000047 product Substances 0.000 abstract 1
- 230000002787 reinforcement Effects 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 238000004873 anchoring Methods 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 238000010276 construction Methods 0.000 description 3
- 238000010030 laminating Methods 0.000 description 3
- 239000011513 prestressed concrete Substances 0.000 description 3
- 239000011435 rock Substances 0.000 description 3
- 238000003466 welding Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 150000003841 chloride salts Chemical class 0.000 description 2
- 238000010924 continuous production Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- 239000002689 soil Substances 0.000 description 2
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 229910001294 Reinforcing steel Inorganic materials 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 238000003915 air pollution Methods 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000005422 blasting Methods 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 239000011083 cement mortar Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000005246 galvanizing Methods 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 210000000056 organ Anatomy 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- NNFCIKHAZHQZJG-UHFFFAOYSA-N potassium cyanide Chemical compound [K+].N#[C-] NNFCIKHAZHQZJG-UHFFFAOYSA-N 0.000 description 1
- 235000011118 potassium hydroxide Nutrition 0.000 description 1
- 239000011150 reinforced concrete Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000005488 sandblasting Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
- B21B45/04—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for de-scaling, e.g. by brushing
- B21B45/08—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for de-scaling, e.g. by brushing hydraulically
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
- C21D8/08—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires for concrete reinforcement
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
- C23C2/024—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by cleaning or etching
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/38—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling sheets of limited length, e.g. folded sheets, superimposed sheets, pack rolling
- B21B2001/383—Cladded or coated products
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Plasma & Fusion (AREA)
- Manufacturing & Machinery (AREA)
- Metal Rolling (AREA)
- Heat Treatment Of Steel (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Coating With Molten Metal (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
- Prevention Of Electric Corrosion (AREA)
- Electric Cable Arrangement Between Relatively Moving Parts (AREA)
- Heat Treatment Of Articles (AREA)
- Pit Excavations, Shoring, Fill Or Stabilisation Of Slopes (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
- Excavating Of Shafts Or Tunnels (AREA)
- Chemical Treatment Of Metals (AREA)
- Laminated Bodies (AREA)
- Heat Treatments In General, Especially Conveying And Cooling (AREA)
- Electroplating Methods And Accessories (AREA)
- Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
- Rolls And Other Rotary Bodies (AREA)
Abstract
Description
A presente invenção refere-se a um processo para o tratamento de aço laminado, em especial aço para betão, aço para elementos de prê-esforço ou similares, para aumentar a resistência â corrosão mediante a aplicação de um reves timento de um metal não ferroso, de preferência zinco, sendo o aço laminado em primeiro lugar dacapado a partir do calor de laminagem e depois, evitando a nova formaçao de escamas de óxidos, sendo aplicado o revestimento ao aço laminado quente.The present invention relates to a process for the treatment of rolled steel, in particular steel for concrete, steel for prestressing elements or the like, to increase corrosion resistance by applying a non-ferrous metal coating. , preferably zinc, the steel being rolled first from the heat of rolling and then, preventing the formation of oxide scales, the coating being applied to hot rolled steel.
Os produtos de aço laminado são usa dos, entre outras coisas, na construção, como aço de construção, neste caso sobretudo na forma de aço de betão, aço para prê-esforço para betão pré-esforçado, bem como para amarrações de anco ragens na terra ou de ancoragens na rocha, etc..Rolled steel products are used, among other things, in construction, as construction steel, in this case mainly in the form of concrete steel, prestressing steel for prestressed concrete, as well as for anchoring moorings in the earth or rock anchors, etc.
No caso da utilização como armaduras para peças de betão, quer se trate de armaduras sem prê-esforço para betão armado, quer como armadura prê-esforçada, ou também como órgão de tracção para uma ancoragem no terreno ou pa ra uma ancoragem na rocha, existe entre o aço das armaduras e o betão em regra uma ligação. Esta união surge, no caso do aço de betão e no betão pré-esforçado, como ligação imediata, espontaneamente, devido ao facto de os elementos da armadura estarem em bebidos no betão e serem estreitamente envolvidos por este e, no caso do betão pré-esforçado, como ligação posterior devido ao facto de os canais de pré-esforço necessários para manter a mobi lidade longitudinal dos órgãos de pré-esforço serem posteriormen te injectados com argamassa de cimento.In the case of use as reinforcement for concrete parts, whether it is prestressed reinforcement for reinforced concrete or prestressed reinforcement, or also as a traction device for ground anchoring or rock anchoring, there is a connection between reinforcement steel and concrete. This connection appears, in the case of concrete steel and prestressed concrete, as an immediate connection, spontaneously, due to the fact that the reinforcement elements are drunk in the concrete and are closely involved by it and, in the case of pre-stressed concrete strained, as a posterior connection due to the fact that the prestressing channels necessary to maintain the longitudinal mobility of the prestressing organs are subsequently injected with cement mortar.
No fabrico do betão resulta, devido â dissolução das partículas de cal contidas no cimento, uma solu ção alcalina com um pH superior a 12. Isso tem como consequência que se forma na superfície exterior dos elementos de armadura uma camada de cobertura de óxido de ferro que passiva e protege contra a corrosão a superfície. Por razões de estabilidade e tam bém por razões construtivas, os elementos de armadura situam-se na maioria dos casos nas zonas periféricas das peças componentes, onde têm de manter uma distância mínima determinada â superfície exterior, o chamado revestimento de betão. Devido â poluição do ar, e no caso das obras de pontes devido à utilização crescente de sal aplicado para eliminar a neve e o gelo, os cloretos disso! vidos nestes meios têm.a possibilidade de penetrar até ao aço, onde destroem a camada de passivação e podem assim agredir direc tamente o aço, no caso de ser insuficiente - e mesmo no caso de ser suficiente - o revestimento de betão. 0 mesmo se aplica ao caso dos órgãos de tracção nas ancoragens na terra ou na rocha onde a acção corrosiva do aço ê provocada pela humidade do solo, pela âgua e os componentes ácidos do solo. Por esta razão, há a necessidade de tomar medidas adicionais de protecção contra a corrosão para esses produtos de aço laminado usado em tais construções.In the manufacture of concrete, an alkaline solution with a pH greater than 12 results from the dissolution of the lime particles contained in the cement. This results in the formation of an iron oxide covering layer on the outer surface of the reinforcement elements. that passive and protects the surface against corrosion. For reasons of stability and also for construction reasons, the reinforcement elements are located in most cases in the peripheral areas of the component parts, where they have to maintain a certain minimum distance from the outer surface, the so-called concrete lining. Due to air pollution, and in the case of bridge works due to the increasing use of salt applied to eliminate snow and ice, the chlorides of it! in these media have the possibility of penetrating into the steel, where they destroy the passivation layer and can thus directly attack the steel, in case it is insufficient - and even if it is sufficient - the concrete coating. The same applies to the case of traction members in anchorages in the earth or rock where the corrosive action of steel is caused by soil moisture, water and acidic components of the soil. For this reason, there is a need to take additional corrosion protection measures for these rolled steel products used in such buildings.
De uma maneira muito geral é conhecido revestir metais, em especial metais ferrosos, com uma camada fina de zinco como protecção contra a ferrugem. São conhecidos para isso vãrios processos. Para a galvanização ou zincagem, mergulham-se as peças a proteger num banho de zinco fundido, que pode eventualmente estar também ligado com alumínio. Para a zincagem electrolítica ou galvânica, utilizam-se banhos ãcidos de sulfatos, de sulfatos e cloretos ou banhos de cianeto de potássio e potassa cáustica. Ê também conhecido fazer a aplicação de revestimentos metálicos por aspersão do metal sob a forma líquida, sendo o metal levado, sob a forma de arame ou de pó, a uma pistola de aspersão, fundido por meio de uma mistura de oxigénio e gãs combustível e pulverizado por meio de ar comprimido. Todos estes processos são caros, mas sobretudo para o tratamento de um produto obtido em grandes quantidades, fabricado num processo contínuo, de grande comprimento, como os aços de betão e os aços para pré-esforço, não são utilizáveis ou são-no apenas com grandes custos de mão-de-obra e financeiros. Acresce que os produtos a revestir naturalmente antes da aplicação de um tal revestimento têm de ser limpos, e os produtos de aço laminado têm que ser libertos da camada de escamas que já desde a laminagem estão ade rentes aos mesmos; isso faz-se usualmente por meio de jactos de areia, por decapagem ou tratamentos análogos.It is generally known to coat metals, especially ferrous metals, with a thin layer of zinc as a protection against rust. Various processes are known for this. For galvanizing or zinc plating, the parts to be protected are immersed in a bath of molten zinc, which may also be connected with aluminum. For electrolytic or galvanic zinc plating, acid baths of sulfates, sulfates and chlorides or baths of potassium cyanide and caustic potash are used. It is also known to apply metallic coatings by spraying the metal in liquid form, the metal being taken, in the form of wire or powder, to a spray gun, melted by means of a mixture of oxygen and combustible gasses and sprayed using compressed air. All of these processes are expensive, but above all for the treatment of a product obtained in large quantities, manufactured in a continuous process, of great length, such as concrete steels and prestressing steels, they are not usable or they are only with large labor and financial costs. In addition, the products to be coated naturally before applying such a coating must be cleaned, and the rolled steel products must be freed from the layer of scales which, since the laminating, are close to them; this is usually done by sandblasting, pickling or similar treatments.
No caso dos produtos de aço laminado fabricados num processo contínuo, tornou-se também conhecido o processo de decapar o produto laminado imediatamente a seguir à laminagem e dotâ-lo com um revestimento resistente à corrosão, por exemplo de zinco, impedindo a formação de novas escamas e com utilização do calor de laminagem (patente americana 2 442 48!:). A decapagem faz-se neste caso na última armação do laminador como consequência de uma diminuição da secção do produto laminado ligada a um estiramento, de modo que as escamas quebradiças sejam rebentadas, de forma que o produto laminado deixe o laminador substancialmente isento de escamas; Para atingir esta situação, depois de deixar o trem de laminagem a uma temperatura de cerca de 980 a 7609 C, o produto laminado é conduzido através de uma câmara fechada, cheia com um gãs desoxidante, de preferência monóxido de carbono, na qual o monóxido de carbono ê queimado pa ra dar diõxido de carbono. Imediatamente a seguir, o produto laminado atravessa uma outra câmara na qual ê revestido por exemplo com zinco sob a forma de pô de zinco que, devido ao calor ainda existente no interior do produto laminado, funde. Como o produto laminado revestido tem, ao deixar esta câmara, ainda uma temperatura de cerca de 700 a 6009 C, ele tem de ser arrefecido rapidamente depois do revestimento a fim de evitar que o pó de zinco aplicado se queime para se transformar em óxido de zinco.In the case of rolled steel products manufactured in a continuous process, the process of stripping the rolled product immediately after rolling and also providing it with a corrosion resistant coating, for example zinc, preventing the formation of new ones, has also become known. scales and using laminating heat (US patent 2 442 48! :). In this case, the pickling is carried out on the last frame of the laminator as a consequence of a decrease in the section of the laminated product connected to a stretch, so that the brittle scales are burst, so that the laminated product leaves the laminator substantially free of scales; To achieve this, after leaving the rolling mill at a temperature of about 980 to 7609 C, the laminated product is conducted through a closed chamber, filled with a deoxidizing gas, preferably carbon monoxide, in which the monoxide of carbon is burned to give carbon dioxide. Immediately thereafter, the laminated product passes through another chamber in which it is coated, for example, with zinc in the form of zinc powder which, due to the heat still existing inside the laminated product, melts. As the coated laminated product still has a temperature of around 700 to 6009 C, when leaving this chamber, it must be cooled quickly after coating to prevent the applied zinc powder from burning to become oxide. zinc.
Também este processo ê relativamente dispendioso. A manutenção da pureza da superfície do produto laminado decapada por meio de uma atmosfera de gãs desoxidante exige não sõ a sua apresentação, condução e manutenção numa atmosfera desoxidante, numa câmara vedada de maneira conveniente, como também a manutenção de uma temperatura apropriada, antes de o produto laminado ser rapidamente arrefecido, com utilização de um outro meio, depois do revestimento.This process is also relatively expensive. Maintaining the purity of the stripped laminated product surface by means of an atmosphere of deoxidizing gases requires not only its presentation, conduction and maintenance in a deoxidizing atmosphere, in a conveniently sealed chamber, but also the maintenance of an appropriate temperature, before the laminated product is rapidly cooled, using another medium, after coating.
Em face do exposto, o objecto da presente invenção consiste num processo para poder revestir produtos de aço laminado numa operação contínua, imediatamente a se guir â operação de laminagem, com a utilização do calor de laminagem e manter o mais baixos possível os custos do processo e da aparelhagem.In view of the above, the object of the present invention is a process to be able to coat rolled steel products in a continuous operation, immediately following the rolling operation, using the rolling heat and keeping the process costs as low as possible and the stereo.
Segunda a presente invenção, o prob lema resolve-se fazendo incidir agua sob pressão no aço laminado no prosseguimento contínuo da laminagem para fazer a decapagem, arrefecendo-se rapidamente a partir de uma temperatura inferior a 6009 C a superfície superior, imediatamente após a decapagem para impedir a formação de novas escamas e aplicando depois disso o revestimento.According to the present invention, the problem is solved by placing water under pressure on the rolled steel in the continuous rolling process to make the pickling, cooling quickly from a temperature below 6009 C to the upper surface, immediately after pickling. to prevent the formation of new scales and then apply the coating.
A vantagem da presente invenção con siste sobretudo no facto de se utilizar, quer para a decapagem, quer para o impedimento da formação de novas escamas e também pa ra o arrefecimento, um unico meio, designadamente a ãgua, podendo o arrefecimento fazer-se de modo tal que o calor de laminagem pode ser usado de uma maneira óptima para o revestimento. Consegue-se desse modo que todas as fases do processo ou operações de tratamento, respectivamente, possam fazer-se continuamente no de curso da operação de laminagem, portanto com a velocidade da laminagem, de modo que o produto final revestido deixa o trem de produção de maneira análoga ã de um produto laminado normal sem tratamento ulterior.The advantage of the present invention consists mainly in the fact that it is used, both for pickling and to prevent the formation of new scales and also for cooling, a unique means, namely water, with cooling being possible. such that laminating heat can be used in an optimal way for the coating. In this way it is achieved that all phases of the process or treatment operations, respectively, can be carried out continuously in the course of the rolling operation, therefore with the rolling speed, so that the final coated product leaves the production train similarly to a normal laminated product without further treatment.
Mediante a incidência na superfície exterior do aço de água sob pressão elevada para a decapagem, utiliza-se a circunstância de as escamas que aderiram ao aço laminado na operação de laminagem e que jã se desprenderam na deformação do produto laminado realizada na última armação do lami nador, por exemplo a passagem da secção oval para uma secção cir cular, poderem ser eliminadas fãcil e totalmente imediatamente depois de o produto laminado deixar a armação do laminador. À ~ - 7 pressão da agua deve ser superior a 2x10 Pa, de preferencia en7 7tre 3x10 a 4x10 Pa; se necessário, pode subir-se atê cerca de oDue to the incidence on the outer surface of the water steel under high pressure for pickling, the circumstance that the scales that adhered to the rolled steel in the rolling operation and that have already become detached in the deformation of the laminated product made in the last frame of the lami is used operator, for example the passage from the oval section to a circular section, can be eliminated easily and completely immediately after the laminated product leaves the laminator frame. At ~ - 7 the water pressure must be greater than 2x10 Pa, preferably between 7 and 3x10 to 4x10 Pa; if necessary, you can climb up to about
Pa. Isso exige apenas um curto tratamento, designadamente a passagem do aço laminado através de um injector, o que tem como consequência uma diminuição insignificante da temperatura do aço laminado.This requires only a short treatment, namely the passage of the rolled steel through an injector, which results in an insignificant decrease in the temperature of the rolled steel.
Enquanto que a decapagem por meio de ãgua sob pressão a partir do calor de laminagem, se efectua a uma temperatura de cerca de 800 a 1 000° C, segundo a presente invenção faz-se, na continuação deste tratamento pela ãgua, de uma maneira contínua e utilizando o mesmo meio, o arrefecimento, de modo tal que a temperatura das escamas baixa a partir dos 6009 C o mais bruscamente possível, que portanto não possam jã formar-se novas escamas e se atinjam temperaturas às quais pode fazer-se o revestimento. Segundo a presente invenção isso pode conseguir-se conduzindo o aço laminado através de um banho de ãgua e se o mesmo for aspergido com água. As temperaturas apropriadas para a aplicação de revestimentos à corrosão são, no caso do alumínio puro, por exemplo uma temperatura de 560 a 570° C e, no caso de zinco puro, uma temperatura de cerca de 4159 C; no caso das ligas podem intercalar-se escalões intermédios. Assim, segundo a presente invenção é sem mais possível utilizar todas as ligas desejadas para o revestimento, visto que, a partir do calor de laminagem até ao arrefecimento, passa-se por toda a gama de temperaturas.While the pickling by means of water under pressure from the heat of rolling, is carried out at a temperature of about 800 to 1 000 ° C, according to the present invention, it is done, in the continuation of this treatment by water, in a way continuous and using the same medium, the cooling, in such a way that the temperature of the scales drops from 6009 C as abruptly as possible, so that new scales can no longer form and reach temperatures at which the coating. According to the present invention this can be achieved by conducting the rolled steel through a water bath and if it is sprayed with water. The appropriate temperatures for applying corrosion coatings are, in the case of pure aluminum, for example a temperature of 560 to 570 ° C and, in the case of pure zinc, a temperature of about 4159 C; in the case of alloys, intermediate steps can be inserted. Thus, according to the present invention it is no longer possible to use all the desired alloys for the coating, since, from the heat of rolling until cooling, the whole temperature range is passed.
A aplicação do revestimento pode fa zer-se de qualquer maneira. O metal não ferroso que forma o revestimento pode ser pulverizado em forma de pó, fundido; o aço laminado pode no entanto ser conduzido através de um banho do me tal não metálico fundido.The application of the coating can be done in any way. The non-ferrous metal that forms the coating can be powdered, melted; the rolled steel can however be conducted through a bath of molten non-metallic metal.
Enquanto que o aço laminado, depois da decapagem, fica protegido pelo tratamento com a ãgua contra a formação de novas escamas, depois da aplicação do revestimento até ao arrefecimento completo do aço lamina, a protecção fica a cargo desse revestimento. Em muitos casos aplica-se sobre o revestimento, por exemplo de zinco, como protecção adicional, ainda uma camada de uma resina sintética, por exemplo uma resina epoxídica. Também essa fase de trabalho pode sem mais ser integrada no processo segundo a presente invenção com a utilização do calor residual.While the laminated steel, after pickling, is protected by the treatment with water against the formation of new scales, after the application of the coating until the complete cooling of the steel laminates, the protection is in charge of that coating. In many cases, a layer of synthetic resin, for example an epoxy resin, is applied over the coating, for example zinc. This working phase can also be integrated into the process according to the present invention with the use of residual heat.
Como o aço laminado, segundo a presente invenção, ê arrefecido com ãgua depois da decapagem, pode esse tratamento com ãgua ser feito também sob a forma do processo, conhecido em si, de revenido, com utilização de ãgua. Um tal processo ê o que ê conhecido, no caso dos aços de betão com pequeno teor de carbono e portanto apropriado para soldadura, por processo Tempcore, no qual o tratamento pela água se faz de mo do tal que no aço laminado existe, imediatamente após o arrefec/ mento brusco, uma zona periférica de martensite e de bainite, en quanto que o calor que permanece no núcleo do aço, durante o arrefecimento seguinte não provoca o revenido da zona periférica para alêm do nível de bainite. No caso dos aços com elevado teor de carbono, apropriados para o pré-esforço, o tratamento pela ãgua ê feito de modo tal que os aços são arrefecidos rapidamente a partir de uma temperatura final de laminagem entre 860 e 1 060Q C de modo tal que na camada periférica se forma uma estrutura completamente martensitica e a temperatura da camada periférica, devido à compensação de temperatura num espaço de tempo entre 2 e 6 segundos apos o início do fenômeno de arrefecimento rápido, ê de 400 a 5009 C. Deste modo, o arrefecimento realizado segundo a presente invenção pode de maneira vantajosa ser usado ainda pa ra melhorar a resistência do aço.As the laminated steel, according to the present invention, is cooled with water after blasting, this water treatment can also be carried out in the form of the process, known in itself, of tempering, with the use of water. Such a process is what is known, in the case of concrete steels with a low carbon content and therefore suitable for welding, by the Tempcore process, in which water treatment is carried out in the same way as in rolled steel, immediately after the sudden cooling, a peripheral zone of martensite and bainite, while the heat that remains in the steel core during the next cooling does not cause the peripheral zone to temper beyond the level of bainite. In the case of steels with a high carbon content, suitable for prestressing, the water treatment is done in such a way that the steels are cooled quickly from a final rolling temperature between 860 and 1 060 ° C so that in the peripheral layer a completely martensitic structure is formed and the temperature of the peripheral layer, due to the temperature compensation in a time between 2 and 6 seconds after the beginning of the rapid cooling phenomenon, is from 400 to 5009 C. In this way, the cooling carried out according to the present invention can advantageously be used to further improve the strength of the steel.
Uma outra vantagem da presente invenção consiste finalmente no facto de todas as fases de trabalho se fazerem continuamente, imediatamente no processo que se segue à laminagem, em estações de tratamento individuais associa das à última armação do laminador. Embora o processo de laminagem, devido à laminagem de barras metálicas, se tenha tornado bastante tradicional de maneira forçosamente discontínua atê ao abandono da última armação do laminador, a presente invenção apresenta naturalmente vantagens especiais, quando antes, mediante a soldadura das barras, a operação de laminagem se transforma numa laminagem sem fim. Isso consegue-se de maneira particularmente vantajosa mediante a soldadura topo a topo por combustão volante, conhecida em si, das barras; na zona entre a salda do forno ou a saída de uma armação de laminagem tripla e a primeira actuação do trem de laminagem fina.A further advantage of the present invention is finally that all working steps are carried out continuously, immediately in the process following rolling, in individual treatment stations associated with the last frame of the rolling mill. Although the rolling process, due to the rolling of metal bars, has become quite traditional in a forcibly discontinuous manner until the abandonment of the last frame of the laminator, the present invention naturally presents special advantages, when before, by welding the bars, the operation rolling mill turns into endless rolling. This is achieved in a particularly advantageous way by means of end-to-end welding by fly combustion, known in itself, of the bars; in the area between the exit of the oven or the exit of a triple rolling frame and the first actuation of the fine rolling mill.
REIVINDICAÇÕES
Claims (1)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3729177A DE3729177C1 (en) | 1987-09-01 | 1987-09-01 | Process for treating rolled steel to increase resistance to corrosion |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| PT88371A PT88371A (en) | 1989-07-31 |
| PT88371B true PT88371B (en) | 1993-02-26 |
Family
ID=6334972
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PT88371A PT88371B (en) | 1987-09-01 | 1988-08-30 | PROCESS FOR THE TREATMENT OF LAMINATED ACID TO INCREASE CORROSION RESISTANCE |
Country Status (15)
| Country | Link |
|---|---|
| EP (1) | EP0305914B1 (en) |
| JP (1) | JPS6475692A (en) |
| CN (1) | CN1031724A (en) |
| AT (1) | ATE70568T1 (en) |
| CA (1) | CA1306391C (en) |
| DD (1) | DD282246A5 (en) |
| DE (2) | DE3729177C1 (en) |
| DK (1) | DK460688A (en) |
| ES (1) | ES2028964T3 (en) |
| GR (1) | GR3004067T3 (en) |
| HU (1) | HU203586B (en) |
| NO (1) | NO176578C (en) |
| PL (1) | PL158408B1 (en) |
| PT (1) | PT88371B (en) |
| SU (1) | SU1674689A3 (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE1005964A6 (en) * | 1992-06-29 | 1994-04-05 | Centre Rech Metallurgique | Protection method of hot rolled steel product. |
| GB2313382A (en) * | 1996-05-23 | 1997-11-26 | Vidal Henri Brevets | Metal coating |
| DE19828827C1 (en) * | 1998-06-27 | 2000-07-20 | Grillo Werke Ag | Thermal sprayed corrosion layer for reinforced concrete and method of manufacturing the same |
| DE102004059008A1 (en) * | 2004-12-08 | 2006-06-14 | Volkswagen Ag | Coating metal components comprises selectively applying a less noble metal than that of the component |
| CN202925384U (en) * | 2012-10-29 | 2013-05-08 | 厦门新钢金属制品有限公司 | Complex coating ballastless track board insulation reinforcing steel bar |
| CN102912692A (en) * | 2012-10-29 | 2013-02-06 | 厦门新钢金属制品有限公司 | Ballastless track slab insulating bar reinforcement with composite coating |
| US20150218815A1 (en) * | 2014-01-31 | 2015-08-06 | Mortar Net Usa, Ltd. | Corrosion resistant structural reinforcement member |
| RU2573304C9 (en) * | 2014-03-11 | 2016-05-20 | Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования Пензенский государственный университет архитектуры и строительства | Increasing life and hardness of rod- and pipe-type reinforcements |
| CN104878332B (en) * | 2015-06-03 | 2017-08-01 | 河北钢铁股份有限公司邯郸分公司 | A kind of raising production method of the hot radical galvanized sheet with product decay resistance |
| DE102016106421A1 (en) | 2016-04-08 | 2017-10-12 | Andrey Senokosov | Cleaning process for riser pipes and equipment therefor |
| CN106040755B (en) * | 2016-07-16 | 2018-02-27 | 太原科技大学 | Cathodic protection rollgang equipped with conductive carrying roller |
| CN106001133B (en) * | 2016-07-16 | 2018-02-27 | 太原科技大学 | It is formed with the rollgang of sagging exposed electric wire cathodic protection |
| CN107794476A (en) * | 2017-09-11 | 2018-03-13 | 常熟市双羽铜业有限公司 | A kind of corrosion resisting steel structural member |
| CN109821923A (en) * | 2019-02-26 | 2019-05-31 | 桂林理工大学 | A kind of production method of anti-corrosion coating plain bar |
| CN115261733B (en) * | 2022-08-18 | 2023-06-06 | 攀钢集团攀枝花钢铁研究院有限公司 | Abrasion-resistant corrosion-resistant steel rail for subway and production method thereof |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2442485A (en) * | 1944-06-24 | 1948-06-01 | Frederick C Cook | Method of descaling and coating hot-rolled ferrous metal |
| DE1602129B1 (en) * | 1967-06-21 | 1970-08-27 | Roechlingsche Eisen & Stahl | Cooling pipe for cooling rolled material |
| DE2108314A1 (en) * | 1970-08-05 | 1972-02-10 | VEB Schwermaschinenbau-Kombinat Ernst Thallmann Magdeburg, χ 3011 Magdeburg | Rapid cooling rolled rod - of structural steel by a controlled - water quench method |
| DE2353034B2 (en) * | 1972-10-31 | 1980-03-13 | Centre De Recherches Metallurgiques- Centrum Voor Research In De Metallurgie, Bruessel | Process for improving the mechanical strength values of rolled steel products |
| DE3125146A1 (en) * | 1981-06-26 | 1983-01-13 | Woma-Apparatebau Wolfgang Maasberg & Co Gmbh, 4100 Duisburg | Device for descaling hot steel ingots |
-
1987
- 1987-09-01 DE DE3729177A patent/DE3729177C1/en not_active Expired
-
1988
- 1988-08-17 DK DK460688A patent/DK460688A/en not_active Application Discontinuation
- 1988-08-18 HU HU884397A patent/HU203586B/en unknown
- 1988-08-24 NO NO883781A patent/NO176578C/en unknown
- 1988-08-25 PL PL1988274389A patent/PL158408B1/en unknown
- 1988-08-26 ES ES198888113916T patent/ES2028964T3/en not_active Expired - Lifetime
- 1988-08-26 SU SU884356320A patent/SU1674689A3/en active
- 1988-08-26 DE DE8888113916T patent/DE3866998D1/en not_active Expired - Fee Related
- 1988-08-26 AT AT88113916T patent/ATE70568T1/en not_active IP Right Cessation
- 1988-08-26 EP EP88113916A patent/EP0305914B1/en not_active Expired - Lifetime
- 1988-08-29 DD DD88319281A patent/DD282246A5/en not_active IP Right Cessation
- 1988-08-30 PT PT88371A patent/PT88371B/en not_active IP Right Cessation
- 1988-08-31 JP JP63215357A patent/JPS6475692A/en active Granted
- 1988-08-31 CA CA000576161A patent/CA1306391C/en not_active Expired - Fee Related
- 1988-08-31 CN CN88106460A patent/CN1031724A/en active Pending
-
1992
- 1992-03-18 GR GR920400458T patent/GR3004067T3/el unknown
Also Published As
| Publication number | Publication date |
|---|---|
| EP0305914A3 (en) | 1989-08-09 |
| DK460688A (en) | 1989-03-02 |
| EP0305914A2 (en) | 1989-03-08 |
| HU203586B (en) | 1991-08-28 |
| DE3729177C1 (en) | 1989-01-05 |
| GR3004067T3 (en) | 1993-03-31 |
| CA1306391C (en) | 1992-08-18 |
| NO176578C (en) | 1995-04-26 |
| DK460688D0 (en) | 1988-08-17 |
| NO883781L (en) | 1989-03-02 |
| EP0305914B1 (en) | 1991-12-18 |
| NO176578B (en) | 1995-01-16 |
| PL158408B1 (en) | 1992-08-31 |
| DE3866998D1 (en) | 1992-01-30 |
| NO883781D0 (en) | 1988-08-24 |
| PT88371A (en) | 1989-07-31 |
| JPH0445591B2 (en) | 1992-07-27 |
| PL274389A1 (en) | 1989-04-17 |
| JPS6475692A (en) | 1989-03-22 |
| ATE70568T1 (en) | 1992-01-15 |
| CN1031724A (en) | 1989-03-15 |
| ES2028964T3 (en) | 1992-07-16 |
| HUT52178A (en) | 1990-06-28 |
| DD282246A5 (en) | 1990-09-05 |
| SU1674689A3 (en) | 1991-08-30 |
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