WO2017129326A1 - Procédé pour protéger des produits en acier trempé thermotraités contre l'oxydation et la décarburation - Google Patents

Procédé pour protéger des produits en acier trempé thermotraités contre l'oxydation et la décarburation Download PDF

Info

Publication number
WO2017129326A1
WO2017129326A1 PCT/EP2016/081791 EP2016081791W WO2017129326A1 WO 2017129326 A1 WO2017129326 A1 WO 2017129326A1 EP 2016081791 W EP2016081791 W EP 2016081791W WO 2017129326 A1 WO2017129326 A1 WO 2017129326A1
Authority
WO
WIPO (PCT)
Prior art keywords
based coating
graphene based
graphene
steel product
heat treatment
Prior art date
Application number
PCT/EP2016/081791
Other languages
English (en)
Inventor
Digvijay THAKUR
Samson PATOLE
Sivasambu BÖHM
Original Assignee
Tata Steel Uk Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tata Steel Uk Limited filed Critical Tata Steel Uk Limited
Priority to EP16810434.7A priority Critical patent/EP3408334B1/fr
Priority to ES16810434T priority patent/ES2795434T3/es
Publication of WO2017129326A1 publication Critical patent/WO2017129326A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients

Definitions

  • the invention relates to a method to protect heat treated steel products against oxidation and decarburisation and a graphene based coating that is used in the method.
  • oxidation and decarburisation of steel substrate may occur.
  • heat treatments are for example forging, heat treatments in furnaces for heat treatable steel such as high carbon steels and hot forming of boron containing steels to produce structural steel components for automotive applications.
  • ultrahigh-strength steels like boron alloys
  • ultrahigh-strength steels pose a major challenge in processing because of their limited formability at room temperature.
  • hot-press forming or hot-stamping technique is utilized, which involved press forming of high tensile steel sheet after it is heated to relative high temperatures.
  • the part is austenitized at a higher temperature of approximately 900°C, and then transferred to a hot forming die where the steel product is pressed into its final shape and cooled at the same time.
  • a hot forming die where the steel product is pressed into its final shape and cooled at the same time.
  • complex shapes can be achieved as the material has excellent formability at high temperatures.
  • the high temperature processing involved in hot forming technique produces side effects such as oxidation and decarburisation of steel surface, resulting in loss of surface quality and reduction in strength.
  • the oxide formed during hot forming result in scale formation on the hot formed product or the oxide can peel- or flake-off and adhere to the hot forming dies resulting in decreased productivity.
  • This scale formed on the hot formed steel product is detrimental to its appearance as well as to the adherence of a protective coating applied to the product.
  • the scale formation is resolved by having an extra shot blasting stage in the hot stamping production line, adding extra cost and lowering production yields.
  • Another prominent challenge faced during hot forming process is the decarburisation of steel sheet surface. Decarburisation or depletion of surface carbon content takes place when steel is heated to temperatures above 650°C. It progresses as a function of time, temperature and atmospheric conditions. Decarburisation of the steel product surface is detrimental for its mechanical properties as depletion of carbon from the surface can decrease its hardness and strength, which can consequently affect the structural integrity of a hot formed product.
  • Heat treatable steel such as high carbon steels
  • Heat treatable steel could also shown decarburisation effects following intermediate heat treatments, such as spheroidisation, under reducing or oxidising atmospheres. These heat treatments could typically go up to 700-800°C and improve microstructure homogeneity and improve cold rolling of high carbon steel.
  • the invention relates to a method as defined in claims 1 - 15 and a graphene based coating as defined in claims 16 and 17.
  • one or more of the objectives are realized by providing a method to prevent or limit oxidation and/or decarburisation of a steel product when subjected to a heat treatment, wherein before subjecting the steel product to the heat treatment a graphene based coating is applied on the steel product.
  • the results are further improved by applying a thick layer of the graphene based coating or more easily by applying successive layers of the graphene based coating on the steel product.
  • the graphene based coating layer is applied with a thickness in the range of 50 -200 pm, more preferably in the range of 80 - 200 pm and even more preferably in the range of 90 - 160 pm.
  • the thickness given is the thickness after curing.
  • the applied layer or layers of graphene based coating are cured preceding the heat treatment of the steel product.
  • the applied layer or layers of graphene based coatings and the applied top coat layer are cured simultaneously.
  • the heat treatment comprises that the steel product reaches a temperature reaches a temperature in the range of 600 - 1000°C. From 600°C the decarburisation of the steel product may already start and is further depending on the time that the product is subjected to such a heat treatment.
  • the method is particularly relevant for heat treatments at higher temperatures such as a heat treatment which comprises that the steel product is subjected to a hot forming step.
  • a heat treatment which comprises that the steel product is subjected to a hot forming step.
  • hot forming the steel product will typically be subjected to a temperature in the order of 900°C with the upper limit being 1000°C.
  • the method is specially suitable for the heat treatment of a steel product wherein the steel product is a high carbon steel or a boron steel.
  • the composition for the graphene based coating comprises a polyurethane primer containing graphene and a corrosion inhibitor.
  • the polyurethane primer forms the bulk material of the graphene based coating.
  • Graphene provides anti-oxidation properties to the graphene based coating and is a thermally stable barrier.
  • the corrosion inhibitor is added to further improve the anti-corrosion properties of the coating.
  • the corrosion inhibitor comprises one or more cations selected from zinc, magnesium, titanium, zirconium, yttrium, lanthanum and cerium. Good results have been achieved by using cerium acetate as the corrosion inhibitor.
  • the composition for the graphene based coating further contains a coupling agent which facilitates the chemical bonding of the graphene based coating to the steel product.
  • the coupling agent can further be selected to have more general adhesions properties as well as cross-linking properties.
  • the cross-linking properties of the coupling agent will result in the cross- linking of multilayer stacks of graphene material aligned parallel along the surface of steel product which will further limit the permeation and/or contact of air/oxygen with the surface of the steel product and therewith further prevent oxide formation.
  • the coupling agent comprises an organofunctional silane.
  • an organofunctional silane Better crosslinking of graphene sheets to polyurethane matrix was achieved with an epoxysilane or a methoxysilane as the organofunctional silane which resulted into a better thermally stable barrier against oxidation.
  • composition for the graphene based coating further contains a siloxane, preferably a dimethylpolysiloxane.
  • the siloxane is added for its properties as a wetting agent.
  • composition for the graphene based coating further contains an additive to maintain the adhesion and to stabilize viscosity of the graphene based coating.
  • the invention further provides a graphene based coating composition for use in the method comprising 0.5 - 10 wt% graphene, 0.01 - 0.5 wt% of a corrosion inhibitor and 2 - 40 wt% of an organofunctional silane and optionally 0.1 - 1.0 wt% of a siloxane containing additive and/or 0.1 - 1.0 wt% of an additive to maintain the adhesion and to stabilize viscosity of the graphene based coating, the balance being polyurethane primer.
  • a thermosetting polyurethane is used than a thermoplastic polyurethane.
  • the thermosetting polyurethane is preferably a thermosetting polyurethane with aliphatic constituents.
  • the graphene based coating composition has a graphene content in the range of 3.0 - 7.0 wt% and an organofunctional silane content in the range of 10 - 30 wt%.
  • the graphene was produced according to the following protocol: 34g graphite (TIMCAL TIMREX ® LSG 6), 150g N-Methyl-2-pyrrolidone (NMP) and 0.5g of DISPERBYK ® 180 (a wetting and dispersing additive) were mixed and subjected to 6 hours of both high shear mixing at 8000 RPM on a SILVERSON ® high shear mixer and an ultrasonic treatment whilst maintaining the temperature below 21 °C with the use of an immersion cooler. This mixture was collected and centrifuged at 600 RPM for 150 minutes. The supernatant was collected and used further in step 2 to produce corresponding formulations.
  • 34g graphite TIMCAL TIMREX ® LSG 6
  • NMP N-Methyl-2-pyrrolidone
  • DISPERBYK ® 180 a wetting and dispersing additive
  • Table 1 enlists the three formulations and corresponding components of formulations and their quantities.
  • SIVO 110 resembles a multifunctional, basically VOC-free, water borne sol-gel system. It is composed of a silica sol, modified with organofunctional silanes. Besides silanol groups it also contains organic functionalities based on Si bonded
  • epoxy groups It is predominantly suited as a binder for temperature curing sol-gel coatings and for sol-gel based hybrid coatings.
  • GLYMO is a bifunctional organosilane possessing a reactive organic epoxide and hydrolyzable inorganic methoxysilyl groups.
  • the dual nature of its reactivity allows the product to bind chemically to both inorganic materials (e.g. glass, metals, fillers) and organic polymers (e.g. thermosets, thermoplastics, elastomers), thus functioning as an adhesion promoter, crosslinking agent and/or surface modifier.
  • Byk-341 is a solution of a polyether modified dimethylpolysiloxane.
  • the solution acts as a silicone based anti-crater additive in solvent-borne and aqueous coatings and promotes substrate wetting.
  • BYK-ES 80 is a solution of an alkylolammonium salt of an unsaturated acidic carboxylic acid ester. This product increases the conductivity of coatings and maintains the film properties (such as adhesion), does not cause yellowing and stabilizes viscosity.
  • Sample preparation Samples with graphene based coatings on a steel sheet (with initial dimensions 300mm *200 mm) were cut to three 100 mm * 140 mm samples for hot stamping and three 300x20 mm samples for pre-hot stamping evaluation. The samples were cut dry in order to prevent contamination of coating surface by lubricants.
  • An electric-fired furnace with un-protected atmosphere was used to heat individual samples to 900°C. Thereafter, manual transfer of heated sample was carried out from the furnace to a stamping tool (in ⁇ 8 seconds) to obtain a typical top-hat part / tool geometry using 30T press with a coated surface facing die (rather than the punch). Simple die-quenching was utilised without any integrated cooling system. Cooling rate was typically >100°C/s above 500°C and >60°C/s between 200 and 500°C.
  • FIG. 5a, b show a side-view, respectively a top-view of a hot formed steel product which was provided with a graphene based coating prior to hot forming
  • Fig.6a, b show light optical microscopy images of a section of the steel product according to fig.5 before and after hot forming
  • Fig.7a, b show a side-view, respectively a top-view of a hot formed steel product which was provided with a graphene based coating prior to hot forming, and
  • Fig.8a-c show light optical microscopy images of a section of the steel product according to fig.7 before and after hot forming and a scanning electron microscopy image of the steel product after hot forming.
  • a hot formed steel product is shown which was not provided with a graphene based coating prior the hot forming step.
  • the analytical results shown in fig.2a-c based on light optical microscopy images (fig.2a, fig.2b) and further cross- sectional analysis of the sample using a scanning electron microscope (SEM) (fig.2c) reveal the formation of a thick oxide layer 2 as a result of the hot forming process.
  • the images show a gap 3 between the martensite substrate 1 and the oxide layer 2.
  • Fig.2a is an image before hot-forming
  • fig.2b,2c are images after hot-forming.
  • a hot formed steel product 1 which was provided with a graphene based coating 4 prior the hot forming step.
  • the graphene based coating 4 was provided on the steel product 1 by means of a draw bar coater, but any other suitable application means can also be used.
  • the coating comprises a liquid phase exfoliated few layer graphene dispersed in polyurethane primer matrix according to Formulation 2 in Table 1 and was applied with a thickness of about 150 ⁇ . The use of this graphene based coating resulted in less oxide 5 formation on the steel product in comparison with the uncoated sample of fig.1 a, b.
  • the thickness directly determined the amount of graphene material available for providing the barrier protection and also the stoichiometric amount of carbon required for sustaining the carbothermal reduction of oxide generated during hot forming.
  • a hot formed steel product 1 which was provided with a coating 8 with two graphene based coating layers and a top coat layer with a total thickness of about 132 m prior the hot forming step.
  • Fig.8a, 8b show light optical microscopy images and fig.8c a scanning electron microscopy image. From the cross sectional light optical microscopy and the SEM analysis, see fig.8b,8c, it is clear that this combination of coating layers 8 has effectively prevented oxide formation and at the same time avoided any carbon depletion near the surface of the steel sheet 1 , resulting in a homogeneous martensite up to and including the sample edge indicated with arrow 10.
  • the coating 8 has been spent as good as completely during hot forming step, indicated with arrow 9. This effectively provides an ideal solution to the typical challenges faced during hot forming process. Since there is no coating remaining on the steel sheet as well as the absence of oxide layer eliminate the need for shot blasting step after hot forming. In case there is some part of coating 8 still remains after the hot forming, due to conductive nature of few layer graphene flakes and partial functionalisation, it can provide benefits such as better weldability and coatability in downstream processing steps.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Wood Science & Technology (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)

Abstract

L'invention concerne un procédé pour empêcher ou limiter l'oxydation et/ou la décarburation d'un produit à base d'acier lorsqu'il est soumis à un traitement thermique, tel que le forgeage et le formage à chaud, ainsi qu'une composition destinée à être utilisée dans le procédé.
PCT/EP2016/081791 2016-01-29 2016-12-19 Procédé pour protéger des produits en acier trempé thermotraités contre l'oxydation et la décarburation WO2017129326A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP16810434.7A EP3408334B1 (fr) 2016-01-29 2016-12-19 Procédé pour protéger des produits en acier traités à chaud contre l'oxydation et la décarburation
ES16810434T ES2795434T3 (es) 2016-01-29 2016-12-19 Método para proteger los productos de acero tratados térmicamente contra la oxidación y la descarburación

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP16153440 2016-01-29
EPEP16153440.9 2016-01-29

Publications (1)

Publication Number Publication Date
WO2017129326A1 true WO2017129326A1 (fr) 2017-08-03

Family

ID=55359386

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2016/081791 WO2017129326A1 (fr) 2016-01-29 2016-12-19 Procédé pour protéger des produits en acier trempé thermotraités contre l'oxydation et la décarburation

Country Status (1)

Country Link
WO (1) WO2017129326A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019095642A1 (fr) * 2017-11-20 2019-05-23 曹熙辰 Composition de revêtement anticorrosion, procédé de préparation d'un revêtement anticorrosion et revêtement anticorrosion
CN111704821A (zh) * 2020-06-19 2020-09-25 中国科学院金属研究所 一种基于氧化石墨烯接枝的复合型防锈颜料及其在防腐涂料中的应用

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2639329A2 (fr) * 2010-11-09 2013-09-18 Posco Tôle d'acier recouverte de graphène, et procédé de fabrication associé
WO2015160764A1 (fr) * 2014-04-14 2015-10-22 The Board Of Regents Of The University Of Texas System Revêtements à base de graphène
EP2939979A1 (fr) * 2012-12-28 2015-11-04 Posco Oxyde de graphène, composite graphène-polymère, liquide de revêtement contenant ledit composite graphène-polymère, tôle recouverte du composite graphène-polymère et procédé de fabrication correspondant

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2639329A2 (fr) * 2010-11-09 2013-09-18 Posco Tôle d'acier recouverte de graphène, et procédé de fabrication associé
EP2939979A1 (fr) * 2012-12-28 2015-11-04 Posco Oxyde de graphène, composite graphène-polymère, liquide de revêtement contenant ledit composite graphène-polymère, tôle recouverte du composite graphène-polymère et procédé de fabrication correspondant
WO2015160764A1 (fr) * 2014-04-14 2015-10-22 The Board Of Regents Of The University Of Texas System Revêtements à base de graphène

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
DUMÉE LUDOVIC F ET AL: "Growth of nano-textured graphene coatings across highly porous stainless steel supports towards corrosion resistant coatings", CARBON, vol. 87, 24 February 2015 (2015-02-24), pages 395 - 408, XP029204878, ISSN: 0008-6223, DOI: 10.1016/J.CARBON.2015.02.042 *
KARANVEER. S. ANEJA ET AL: "Graphene based anticorrosive coatings for Cr(VI) replacement", NANOSCALE, vol. 7, no. 42, 28 September 2015 (2015-09-28), United Kingdom, pages 17879 - 17888, XP055273332, ISSN: 2040-3364, DOI: 10.1039/C5NR04702A *
MD J. NINE ET AL: "Graphene: a multipurpose material for protective coatings", JOURNAL OF MATERIALS CHEMISTRY A: MATERIALS FOR ENERGY AND SUSTAINABILITY, vol. 3, no. 24, 2 April 2015 (2015-04-02), GB, pages 12580 - 12602, XP055273349, ISSN: 2050-7488, DOI: 10.1039/C5TA01010A *
YAYA LI ET AL: "Self-aligned graphene as anticorrosive barrier in waterborne polyurethane composite coatings", JOURNAL OF MATERIALS CHEMISTRY A: MATERIALS FOR ENERGY AND SUSTAINABILITY, vol. 2, no. 34, 4 July 2014 (2014-07-04), GB, pages 14139, XP055273344, ISSN: 2050-7488, DOI: 10.1039/C4TA02262A *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019095642A1 (fr) * 2017-11-20 2019-05-23 曹熙辰 Composition de revêtement anticorrosion, procédé de préparation d'un revêtement anticorrosion et revêtement anticorrosion
CN111704821A (zh) * 2020-06-19 2020-09-25 中国科学院金属研究所 一种基于氧化石墨烯接枝的复合型防锈颜料及其在防腐涂料中的应用
CN111704821B (zh) * 2020-06-19 2021-07-23 中国科学院金属研究所 一种基于氧化石墨烯接枝的复合型防锈颜料及其在防腐涂料中的应用

Similar Documents

Publication Publication Date Title
JP5419457B2 (ja) 金属、特に鋼を腐食及び／又はスケーリングから保護するためのコーティング剤、並びに金属及び金属部品のコーティング方法
KR101974182B1 (ko) 열간 프레스용 도금 강판 및 도금 강판의 열간 프레스 방법
JP4939013B2 (ja) ホットプレス用溶融Ｚｎめっき鋼板およびホットプレス成形材
WO2009131233A1 (fr) Tôle d'acier plaquée et procédé de pressage à chaud de tôle d'acier plaquée
KR102075214B1 (ko) 우수한 내식성 및 내흑변성을 부여하는 삼원계 용융아연합금 도금강판용 표면처리 용액 조성물, 이를 이용하여 표면처리된 삼원계 용융아연합금 도금강판 및 그 제조 방법
KR101414019B1 (ko) 무기 도막 형성 방법
CN108778716B (zh) 聚烯烃系树脂粘接用表面处理金属板及使用其的复合构件
EP2743320B1 (fr) Procédé en plusieurs étapes de recouvrement d'acier avant un formage à chaud
WO2016195101A1 (fr) Liquide de traitement de surface pour tôle d'acier plaquée devant être pressée à chaud
EP3408334B1 (fr) Procédé pour protéger des produits en acier traités à chaud contre l'oxydation et la décarburation
WO2012074132A1 (fr) Procédé de fabrication d'un élément pressé à chaud
WO2017129326A1 (fr) Procédé pour protéger des produits en acier trempé thermotraités contre l'oxydation et la décarburation
WO2013056848A1 (fr) Revêtements anti-incrustation et anticorrosion pour des substrats en acier
KR101913076B1 (ko) 고강도 자동차용 용융아연합금 도금강선의 제조방법 및 이에 의하여 제조된 용융아연합금 도금강선
EP2510061A2 (fr) Revêtements protecteurs pour substrats
CN114150252A (zh) 一种镀层热成形钢板、具有优良胶粘性能的热冲压零部件及制造方法和应用
JP2008231551A (ja) 耐テンパーカラー性に優れたステンレス鋼材およびその製造法
JP6965992B2 (ja) 金属−炭素繊維強化樹脂材料複合体及び金属−炭素繊維強化樹脂材料複合体の製造方法
WO2013056847A1 (fr) Revêtements hybrides anti-tartre et anti-corrosion pour substrats en acier
WO2017169571A1 (fr) Plaque métallique avec traitement chimique de conversion ainsi que procédé de fabrication de celle-ci, plaque métallique avec traitement de surface, et élément composite
CN104830172B (zh) 用于车辆部件的表面及其制造方法
CA3104849C (fr) Tole d'acier electromagnetique sur laquelle est fixe un film de revetement isolant, et procede pour la produire
KR101377627B1 (ko) 고온에서 발생되는 산화에 의한 금속모재의 박리를 방지하는 세라믹 코팅 조성물
WO2017195802A1 (fr) Matériau en alliage d'aluminium, matériau en alliage d'aluminium ayant une couche de résine adhésive, procédé de production de matériau en alliage d'aluminium, et procédé de production de matériau en alliage d'aluminium ayant une couche de résine adhésive

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16810434

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE