WO2019192181A1 - Cold-rolled, high-strength, hot-dip galvanized steel sheet and production method thereof - Google Patents

Cold-rolled, high-strength, hot-dip galvanized steel sheet and production method thereof Download PDF

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WO2019192181A1
WO2019192181A1 PCT/CN2018/115296 CN2018115296W WO2019192181A1 WO 2019192181 A1 WO2019192181 A1 WO 2019192181A1 CN 2018115296 W CN2018115296 W CN 2018115296W WO 2019192181 A1 WO2019192181 A1 WO 2019192181A1
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hydrogen
steel sheet
alloy layer
cold
heat treatment
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PCT/CN2018/115296
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French (fr)
Chinese (zh)
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蒋光锐
王海全
滕华湘
朱国森
韩赟
李研
谢春乾
刘华赛
刘李斌
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首钢集团有限公司
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    • 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
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • 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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/68—Temporary coatings or embedding materials applied before or during heat treatment
    • C21D1/70—Temporary coatings or embedding materials applied before or during heat treatment while heating or quenching
    • 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
    • C21D3/00—Diffusion processes for extraction of non-metals; Furnaces therefor
    • C21D3/02—Extraction of non-metals
    • C21D3/06—Extraction of hydrogen
    • 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
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0257—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment with diffusion of elements, e.g. decarburising, nitriding
    • 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
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0278—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips involving a particular surface treatment
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • 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
    • C23C2/022—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating
    • 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
    • C23C2/022—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating
    • C23C2/0224—Two or more thermal pretreatments
    • 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
    • C23C2/026—Deposition of sublayers, e.g. adhesion layers or pre-applied alloying elements or corrosion protection
    • 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
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/06—Zinc or cadmium or alloys based thereon
    • 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
    • C23C2/26—After-treatment
    • 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
    • C23C2/34—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
    • C23C2/36—Elongated material
    • C23C2/40—Plates; Strips
    • 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
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/02—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material
    • 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
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/02—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material
    • C23C28/023—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material only coatings of metal elements only
    • C23C28/025—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material only coatings of metal elements only with at least one zinc-based layer

Definitions

  • the invention relates to a cold-rolled high-strength hot-dip galvanized steel sheet and a production method thereof, and belongs to the technical field of rolling steel.
  • Cold rolled high strength hot-dip galvanized steel sheets are commonly used in the production of automobile bodies. In order to obtain higher strength and good plasticity, cold-rolled high-strength hot-dip galvanized steel sheets are often subjected to phase transformation strengthening. This phase-strengthened cold-rolled high-strength hot-dip galvanized steel sheet often requires a rapid cooling stage during heat treatment. High temperature heating stage.
  • the production process of cold-rolled high-strength hot-dip galvanized steel sheet generally includes: obtaining slab after molten steel smelting, heating the slab, and then performing rough rolling, finish rolling, cooling, cold rolling, heat treatment, hot-dip galvanizing and coiling .
  • the cold-rolled high-strength hot-dip galvanized steel sheet absorbs hydrogen in the annealing atmosphere significantly during the heat treatment.
  • the absorbed hydrogen is thermodynamically unstable at room temperature, tends to precipitate from the steel, and forms between the steel grains. Microscopic defects, precipitated pores and even macroscopic cracks all significantly reduce the strength, plasticity, fatigue properties and other performances of high-strength steel. The so-called hydrogen embrittlement problem occurs, and the steel sheet breaks due to hydrogen during use.
  • the main object of the present invention is to provide a cold-rolled high-strength hot-dip galvanized steel sheet and a production method thereof, which solve the problem that the content of hydrogen in the cold-rolled high-strength hot-dip galvanized steel sheet in the prior art is large and easy.
  • the technical problem of hydrogen embrittlement risk arises, and the technical effect of reducing the hydrogen content in the cold-rolled high-strength hot-dip galvanized steel sheet and greatly reducing the risk of hydrogen embrittlement is achieved.
  • the present invention provides a cold-rolled high-strength hot-dip galvanized steel sheet comprising a layer of an alloy layer between the plating layer and the substrate of the cold-rolled high-strength hot-dip galvanized steel sheet, the alloy layer having a thickness of 10-100 nm.
  • the thickness of the alloy layer is preferably from 50 to 100 nm.
  • the high-temperature solubility of hydrogen in the alloy layer is more than two times lower than the high-temperature solubility of hydrogen in austenite.
  • the high-temperature diffusion coefficient of hydrogen in the alloy layer is more than two times lower than the high-temperature diffusion coefficient of hydrogen in the austenite.
  • Another aspect of the present invention provides a method for producing the above-described cold-rolled high-strength hot-dip galvanized steel sheet, comprising the following steps:
  • the slab After the molten steel is smelted, the slab is obtained, and the slab is heated, and then subjected to rough rolling, finish rolling, cooling, cold rolling, surface treatment, heat treatment, hot-dip galvanizing and coiling; wherein the surface treatment is in the The surface of the steel sheet covers the alloy layer; the heat treatment process includes an overage heat treatment.
  • the alloy layer has a thickness of 10 to 100 nm.
  • the thickness of the alloy layer is preferably from 50 to 100 nm.
  • the high-temperature solubility of hydrogen in the alloy layer is more than two times lower than the high-temperature solubility of hydrogen in austenite.
  • the high-temperature diffusion coefficient of hydrogen in the alloy layer is more than two times lower than the high-temperature diffusion coefficient of hydrogen in austenite.
  • the temperature of the overage heat treatment is in the range of 200 to 300 °C.
  • the hydrogen content in the atmosphere during the overaging heat treatment is not more than 1%.
  • the time of the overaging heat treatment is not less than 30 seconds.
  • the steel sheet is immediately subjected to the hot-dip galvanizing treatment.
  • FIG. 1 is a flow chart showing a method for producing a cold-rolled high-strength hot-dip galvanized steel sheet according to the present invention.
  • the embodiment of the invention provides a cold-rolled high-strength hot-dip galvanized steel sheet and a production method thereof, which solves the technical problem that the hydrogen content in the cold-rolled high-strength hot-dip galvanized steel sheet in the prior art is large and the risk of hydrogen embrittlement is easy to occur. Reducing the hydrogen content in the cold-rolled high-strength hot-dip galvanized steel sheet greatly reduces the technical effect of hydrogen embrittlement risk.
  • the present invention provides a cold-rolled high-strength galvanized steel sheet, wherein the cold-rolled high-strength galvanized steel sheet includes an alloy layer between the plating layer and the substrate, and the alloy layer has a thickness of 10 to 100 nm.
  • the thickness of the alloy layer is preferably from 50 to 100 nm.
  • the production process of cold-rolled high-strength hot-dip galvanized steel sheet generally includes: obtaining slab after molten steel smelting, heating the slab, and then performing rough rolling, finish rolling, cooling, cold rolling, heat treatment, hot-dip galvanizing and rolling take.
  • the smelting process and the hot rolling process are usually carried out in an oxygen-rich environment, and the absorbed hydrogen is extremely small, less than 1 ppm, and the main part of absorbing hydrogen is in the heat treatment process.
  • the present invention adds the surface treatment before the heat treatment, and the surface of the steel sheet is covered with an alloy layer. Wherein the surface treatment is to cover the surface of the steel sheet with an alloy layer.
  • the high temperature solubility of hydrogen in the alloy layer is more than two times lower than the high temperature solubility of hydrogen in austenite.
  • the high temperature diffusion coefficient of hydrogen in the alloy layer is more than 2 times lower than the high temperature diffusion coefficient of hydrogen in austenite.
  • the solubility and diffusion speed of hydrogen in the alloy layer are as small as possible.
  • the test results show that under the current production process conditions, if the high temperature solubility of hydrogen in the alloy layer is more than 2 times lower than the high temperature solubility of hydrogen in austenite, even if the hydrogen in the alloy layer reaches a saturated state, It also greatly reduces the absorption of hydrogen in steel. Meanwhile, if the high temperature diffusion coefficient of hydrogen in the alloy layer is more than 2 times lower than the high temperature diffusion coefficient in austenite, hydrogen diffusion will be mainly hindered by the alloy layer and it is difficult to penetrate into the steel.
  • the alloy plating layer has a thickness of 10 to 100 nm.
  • the barrier effect of the alloy layer on hydrogen is affected by the thickness of the alloy layer. If the thickness of the alloy layer exceeds 10 nm, and the solubility and diffusion rate of hydrogen in the alloy layer satisfy the above requirements, the content of hydrogen at the interface position between the steel and the alloy layer is negligible. However, the thickness of the alloy layer does not increase indefinitely. On the one hand, the thickness of the alloy layer is too thick to significantly affect the performance of the cold-rolled high-strength hot-dip galvanized steel sheet.
  • the thickness of the alloy layer is too thick, which also weakens the bonding force between the steel and the hot-dip galvanized coating. Therefore, the thickness of the alloy layer in the present invention ranges from 10 nm to 100 nm, and the preferred alloy layer thickness ranges from 50 nm to 100 nm.
  • the present invention provides a method for producing a cold-rolled high-strength hot-dip galvanized steel sheet, comprising: obtaining a slab after molten steel smelting, heating the slab, and then performing rough rolling, finish rolling, cooling, and cooling Rolling, surface treatment, heat treatment, hot dip galvanizing and coiling; wherein the surface treatment is to cover the surface of the steel sheet with an alloy layer; the heat treatment process comprises an overaging heat treatment.
  • the present invention adds the surface treatment before the heat treatment, and the surface of the steel sheet is covered with an alloy layer.
  • the surface treatment is to cover the surface of the steel sheet with an alloy layer.
  • the high-temperature solubility of hydrogen in the alloy layer is more than two times lower than the high-temperature solubility of hydrogen in austenite.
  • the high-temperature diffusion coefficient of hydrogen in the alloy layer is more than two times lower than the high-temperature diffusion coefficient of hydrogen in austenite.
  • the hindrance of the alloy layer to hydrogen is affected by the thickness of the alloy layer. If the thickness of the alloy layer exceeds 10 nm, and the solubility and diffusion rate of hydrogen in the alloy layer satisfy the above requirements, the content of hydrogen at the interface position between the steel and the alloy layer is negligible. However, the thickness of the alloy layer does not increase indefinitely. On the one hand, the thickness of the alloy layer is too thick to significantly affect the performance of the cold-rolled high-strength hot-dip galvanized steel sheet. On the other hand, the thickness of the alloy layer is too thick, which also weakens the bonding force between the steel and the hot-dip galvanized coating. Therefore, the thickness of the alloy layer in the present invention ranges from 10 nm to 100 nm, and the preferred alloy layer thickness ranges from 50 nm to 100 nm.
  • the heat treatment process includes an overage heat treatment.
  • the present invention adds the overage heat treatment in the heat treatment process.
  • the purpose of the overaging heat treatment is to diffuse hydrogen atoms in the steel sheet to the surface of the steel sheet and remove them in time.
  • the temperature of the overage heat treatment ranges from 200 to 300 °C.
  • the steel sheet In order for the hydrogen to have sufficient kinetic factors to diffuse out, the steel sheet must have a certain temperature, and the temperature of the outdated heat treatment of the present invention should be not lower than 200 °C.
  • the temperature of the overaging heat treatment is too high, the grain structure of the steel sheet is adversely affected, such as causing martensite decomposition, bainite coarsening, and lamellar martensite transformation into needle martensite. , precipitation of carbides in ferrite, and the like. Therefore, in the present invention, the temperature of the overaging heat treatment is not more than 300 ° C, that is, the temperature of the overaging heat treatment is in the range of 200 to 300 ° C.
  • the hydrogen content in the atmosphere during the overaging heat treatment is not more than 1%, so that the hydrogen diffused to the surface of the steel sheet can be removed in time.
  • the time of the overaging heat treatment is not less than 30 seconds.
  • the diffusion of hydrogen in the steel sheet takes a certain time, and the thickness of the cold-rolled high-strength galvanized steel sheet generally ranges from 0.5 mm to 3 mm. It is known from calculation that the diffusion time of hydrogen takes at least 30 seconds, and the overaging heat treatment is prescribed in the present invention. The time is no less than 30 seconds.
  • the steel sheet is immediately subjected to the hot-dip galvanizing treatment so that the steel sheet does not absorb hydrogen after the overaging heat treatment.
  • a cold-rolled high-strength galvanized steel sheet and a method for producing the same according to an embodiment of the present invention wherein the cold-rolled high-strength galvanized steel sheet has an alloy layer between the plating layer and the substrate, and the alloy layer has a thickness of 10 -100 nm, the high temperature solubility of hydrogen in the alloy layer is more than 2 times lower than the high temperature solubility of hydrogen in austenite, and the high temperature diffusion coefficient of hydrogen in the alloy layer is higher than the high temperature diffusion coefficient of hydrogen in austenite. 2 times lower.
  • the production method comprises: obtaining slab after molten steel smelting, heating the slab, and then performing rough rolling, finish rolling, cooling, cold rolling, surface treatment, heat treatment, hot-dip galvanizing and coiling; wherein The surface treatment is to cover the surface of the steel sheet with an alloy layer; the heat treatment process includes an overaging heat treatment.
  • the technical effect of allowing hydrogen to have sufficient power to diffuse out of the steel sheet to reduce the hydrogen content in the steel sheet is achieved.
  • the hydrogen content in the atmosphere during the overaging heat treatment is not more than 1%, and the technical effect of timely removing the hydrogen diffused to the surface of the steel sheet is achieved.
  • the steel sheet is immediately subjected to the hot-dip galvanizing treatment to achieve a technical effect that the steel sheet no longer absorbs hydrogen after the overaging heat treatment to reduce the hydrogen content in the steel sheet.
  • the present invention uses the hydrogen content in the steel sheet to evaluate the risk of hydrogen embrittlement of the steel sheet. It is generally considered that the risk of hydrogen embrittlement is within an acceptable range when the hydrogen content in the steel sheet is less than 1 ppm.
  • the hydrogen content is less than 1 ppm, and the risk of hydrogen embrittlement is within a controllable range.
  • the invention proves that the method of the invention can solve the technical problem that the hydrogen content in the cold-rolled high-strength hot-dip galvanized steel sheet in the prior art is large, and the risk of hydrogen embrittlement is easy to occur, and the high-strength of cold rolling is achieved.
  • the content of hydrogen in the hot-dip galvanized steel sheet greatly reduces the technical effect of the risk of hydrogen embrittlement.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Coating With Molten Metal (AREA)

Abstract

Disclosed is a cold-rolled, high-strength, hot-dip galvanized steel sheet and a production method thereof. A coating layer and a substrate of the steel sheet comprise an alloy layer disposed therebetween. The thickness of the alloy layer is 10-100 nm. The high-temperature solubility of hydrogen in the alloy layer is at least two times less than the high-temperature solubility of hydrogen in austenite. The high-temperature diffusion coefficient of hydrogen in the alloy layer is at least two times less than the high-temperature diffusion coefficient of hydrogen in austenite. The production method comprises: obtaining a slab after molten steel smelting; heating the slab; and then performing rough rolling, finish rolling, cooling, cold rolling, surface treatment, heat treatment, hot-dip galvanizing and coiling. The surface treatment refers to covering the surface of the steel sheet with the alloy layer. The heat treatment process includes an aging heat treatment. The technical effects achieved include reduced hydrogen content in the cold-rolled, high-strength, hot-dip galvanized steel sheet and reduced risk of hydrogen embrittlement.

Description

一种冷轧高强热镀锌钢板及其生产方法Cold rolled high-strength hot-dip galvanized steel sheet and production method thereof 技术领域Technical field
本发明涉及一种冷轧高强热镀锌钢板及其生产方法，属于轧钢技术领域。The invention relates to a cold-rolled high-strength hot-dip galvanized steel sheet and a production method thereof, and belongs to the technical field of rolling steel.
背景技术Background technique
冷轧高强热镀锌钢板通常被用于生产汽车车身。为了获得更高的强度和良好塑性，目前冷轧高强热镀锌钢板往往采用相变强化的方式，这种相变强化的冷轧高强热镀锌钢板往往要求在热处理过程中有快速冷却阶段和高温加热阶段。目前，冷轧高强热镀锌钢板生产流程一般包括：钢水冶炼后获得板坯，将所述板坯进行加热，再经过粗轧、精轧、冷却、冷轧、热处理、热镀锌和卷取。Cold rolled high strength hot-dip galvanized steel sheets are commonly used in the production of automobile bodies. In order to obtain higher strength and good plasticity, cold-rolled high-strength hot-dip galvanized steel sheets are often subjected to phase transformation strengthening. This phase-strengthened cold-rolled high-strength hot-dip galvanized steel sheet often requires a rapid cooling stage during heat treatment. High temperature heating stage. At present, the production process of cold-rolled high-strength hot-dip galvanized steel sheet generally includes: obtaining slab after molten steel smelting, heating the slab, and then performing rough rolling, finish rolling, cooling, cold rolling, heat treatment, hot-dip galvanizing and coiling .
但本申请发明人在实现本申请实施例中技术方案的过程中，发现上述现有技术至少存在如下技术问题：However, in the process of implementing the technical solution in the embodiment of the present application, the inventor of the present application found that the above prior art has at least the following technical problems:
冷轧高强热镀锌钢板在热处理过程中就会显著吸收退火气氛中的氢，这种吸收的氢在室温条件下热力学并不稳定，倾向于从钢中析出，在钢的晶粒之间形成显微缺陷、析出气孔甚至宏观裂纹，这些缺陷都显著降低了高强钢的强度、塑性、疲劳性能等使用性能，出现所谓氢脆的问题，钢板在使用过程中出现由于氢造成的断裂。The cold-rolled high-strength hot-dip galvanized steel sheet absorbs hydrogen in the annealing atmosphere significantly during the heat treatment. The absorbed hydrogen is thermodynamically unstable at room temperature, tends to precipitate from the steel, and forms between the steel grains. Microscopic defects, precipitated pores and even macroscopic cracks all significantly reduce the strength, plasticity, fatigue properties and other performances of high-strength steel. The so-called hydrogen embrittlement problem occurs, and the steel sheet breaks due to hydrogen during use.
发明内容Summary of the invention
针对现有技术中的上述缺陷，本发明的主要目的在于提供一种冷轧高强热镀锌钢板及其生产方法，解决了现有技术中冷轧高强热镀锌钢板中氢的含量大，易出现氢脆风险的技术问题，达到降低冷轧高强热镀锌钢板中的氢含量以及大大降低氢脆风险的技术效果。In view of the above defects in the prior art, the main object of the present invention is to provide a cold-rolled high-strength hot-dip galvanized steel sheet and a production method thereof, which solve the problem that the content of hydrogen in the cold-rolled high-strength hot-dip galvanized steel sheet in the prior art is large and easy. The technical problem of hydrogen embrittlement risk arises, and the technical effect of reducing the hydrogen content in the cold-rolled high-strength hot-dip galvanized steel sheet and greatly reducing the risk of hydrogen embrittlement is achieved.
本发明一方面提供了一种冷轧高强热镀锌钢板，冷轧高强热镀锌钢板的镀 层与基板之间包含有一层合金层，合金层的厚度为10-100nm。In one aspect, the present invention provides a cold-rolled high-strength hot-dip galvanized steel sheet comprising a layer of an alloy layer between the plating layer and the substrate of the cold-rolled high-strength hot-dip galvanized steel sheet, the alloy layer having a thickness of 10-100 nm.
进一步地，所述合金层的厚度优选为50-100nm。Further, the thickness of the alloy layer is preferably from 50 to 100 nm.
根据本发明所述冷轧高强热镀锌钢板，氢在合金层中的高温溶解度比氢在奥氏体中的高温溶解度低2倍以上。According to the cold-rolled high-strength galvanized steel sheet according to the present invention, the high-temperature solubility of hydrogen in the alloy layer is more than two times lower than the high-temperature solubility of hydrogen in austenite.
根据本发明所述冷轧高强热镀锌钢板，氢在合金层中的高温扩散系数比氢在奥氏体中的高温扩散系数低2倍以上。According to the cold-rolled high-strength galvanized steel sheet according to the present invention, the high-temperature diffusion coefficient of hydrogen in the alloy layer is more than two times lower than the high-temperature diffusion coefficient of hydrogen in the austenite.
本发明另一方面提供了上述冷轧高强热镀锌钢板的生产方法，包括如下步骤：Another aspect of the present invention provides a method for producing the above-described cold-rolled high-strength hot-dip galvanized steel sheet, comprising the following steps:
钢水冶炼后获得板坯，将所述板坯进行加热，再经过粗轧、精轧、冷却、冷轧、表面处理、热处理、热镀锌和卷取；其中，所述表面处理是在所述钢板表面覆盖合金层；所述热处理过程包含过时效热处理。After the molten steel is smelted, the slab is obtained, and the slab is heated, and then subjected to rough rolling, finish rolling, cooling, cold rolling, surface treatment, heat treatment, hot-dip galvanizing and coiling; wherein the surface treatment is in the The surface of the steel sheet covers the alloy layer; the heat treatment process includes an overage heat treatment.
根据本发明所述冷轧高强热镀锌钢板的生产方法，所述合金层的厚度为10-100nm。According to the method for producing a cold-rolled high-strength galvanized steel sheet according to the present invention, the alloy layer has a thickness of 10 to 100 nm.
进一步地，所述合金层的厚度优选为50-100nm。Further, the thickness of the alloy layer is preferably from 50 to 100 nm.
根据本发明所述冷轧高强热镀锌钢板的生产方法，氢在所述合金层中的高温溶解度比氢在奥氏体中的高温溶解度低2倍以上。According to the method for producing a cold-rolled high-strength galvanized steel sheet according to the present invention, the high-temperature solubility of hydrogen in the alloy layer is more than two times lower than the high-temperature solubility of hydrogen in austenite.
根据本发明所述冷轧高强热镀锌钢板的生产方法，氢在所述合金层中的高温扩散系数比氢在奥氏体中的高温扩散系数低2倍以上。According to the method for producing a cold-rolled high-strength galvanized steel sheet according to the present invention, the high-temperature diffusion coefficient of hydrogen in the alloy layer is more than two times lower than the high-temperature diffusion coefficient of hydrogen in austenite.
根据本发明所述冷轧高强热镀锌钢板的生产方法，所述过时效热处理的温度范围为200-300℃。According to the method for producing a cold-rolled high-strength galvanized steel sheet according to the present invention, the temperature of the overage heat treatment is in the range of 200 to 300 °C.
根据本发明所述冷轧高强热镀锌钢板的生产方法，所述过时效热处理时气氛中氢气含量不超过1％。According to the method for producing a cold-rolled high-strength hot-dip galvanized steel sheet according to the present invention, the hydrogen content in the atmosphere during the overaging heat treatment is not more than 1%.
根据本发明所述冷轧高强热镀锌钢板的生产方法，所述过时效热处理的时间不少于30秒。According to the method for producing a cold-rolled high-strength galvanized steel sheet according to the present invention, the time of the overaging heat treatment is not less than 30 seconds.
根据本发明所述冷轧高强热镀锌钢板的生产方法，所述过时效热处理之 后，所述钢板立刻进行所述热镀锌处理。According to the method for producing a cold-rolled high-strength galvanized steel sheet according to the present invention, after the overaging heat treatment, the steel sheet is immediately subjected to the hot-dip galvanizing treatment.
上述说明仅是本发明技术方案的概述，为了能够更清楚了解本发明的技术手段，而可依照说明书的内容予以实施，并且为了让本发明的上述和其它目的、特征和优点能够更明显易懂，以下特举本发明的具体实施方式。The above description is only an overview of the technical solutions of the present invention, and the above-described and other objects, features and advantages of the present invention can be more clearly understood. Specific embodiments of the invention are set forth below.
附图说明DRAWINGS
图1为本发明所述一种冷轧高强热镀锌钢板的生产方法的流程图。1 is a flow chart showing a method for producing a cold-rolled high-strength hot-dip galvanized steel sheet according to the present invention.
具体实施方式detailed description
本发明实施例提供了一种冷轧高强热镀锌钢板及其生产方法，解决了现有技术中冷轧高强热镀锌钢板中氢的含量大，易出现氢脆风险的技术问题，达到了降低冷轧高强热镀锌钢板中氢的含量，大大降低氢脆风险的技术效果。The embodiment of the invention provides a cold-rolled high-strength hot-dip galvanized steel sheet and a production method thereof, which solves the technical problem that the hydrogen content in the cold-rolled high-strength hot-dip galvanized steel sheet in the prior art is large and the risk of hydrogen embrittlement is easy to occur. Reducing the hydrogen content in the cold-rolled high-strength hot-dip galvanized steel sheet greatly reduces the technical effect of hydrogen embrittlement risk.
一方面，本发明提供了一种冷轧高强热镀锌钢板，其中所述冷轧高强热镀锌钢板的镀层与基板之间包含有一层合金层，合金层的厚度为10-100nm。In one aspect, the present invention provides a cold-rolled high-strength galvanized steel sheet, wherein the cold-rolled high-strength galvanized steel sheet includes an alloy layer between the plating layer and the substrate, and the alloy layer has a thickness of 10 to 100 nm.
进一步地，所述合金层的厚度优选为50-100nm。Further, the thickness of the alloy layer is preferably from 50 to 100 nm.
由于冷轧高强热镀锌钢板的氢脆风险在于溶解在钢中的氢原子析出，因此想要彻底解决氢脆风险，需要尽量消除溶解的氢原子。冷轧高强热镀锌钢板表面覆盖一层锌，而氢在锌中的溶解度很低，因此，冷轧高强热镀锌钢板在使用过程中不会从环境中吸收氢，钢板中所有吸收的氢都来自于热镀锌工艺之前。目前，冷轧高强热镀锌钢板的生产流程一般包括：钢水冶炼后获得板坯，将所述板坯进行加热，再经过粗轧、精轧、冷却、冷轧、热处理、热镀锌和卷取。在冷轧高强热镀锌钢板的生产流程中，冶炼环节和热轧环节通常是在富氧环境中进行，吸收的氢极少，低于1ppm，主要吸收氢的环节是在热处理环节。为了避免冷轧高强热镀锌钢板在所述热处理过程中的氢吸收，本发明在所述热处理之前增加了所述表面处理，在所述钢板表面覆盖一层合金层。其中，所述表 面处理是在所述钢板表面覆盖合金层。Since the hydrogen embrittlement risk of cold-rolled high-strength galvanized steel sheets is that hydrogen atoms dissolved in the steel are precipitated, it is necessary to completely eliminate the dissolved hydrogen atoms in order to completely solve the hydrogen embrittlement risk. Cold-rolled high-strength hot-dip galvanized steel sheet is covered with a layer of zinc, and the solubility of hydrogen in zinc is very low. Therefore, cold-rolled high-strength hot-dip galvanized steel sheet does not absorb hydrogen from the environment during use, and all absorbed hydrogen in the steel sheet Both come from the hot dip galvanizing process. At present, the production process of cold-rolled high-strength hot-dip galvanized steel sheet generally includes: obtaining slab after molten steel smelting, heating the slab, and then performing rough rolling, finish rolling, cooling, cold rolling, heat treatment, hot-dip galvanizing and rolling take. In the production process of cold-rolled high-strength hot-dip galvanized steel sheet, the smelting process and the hot rolling process are usually carried out in an oxygen-rich environment, and the absorbed hydrogen is extremely small, less than 1 ppm, and the main part of absorbing hydrogen is in the heat treatment process. In order to avoid hydrogen absorption of the cold-rolled high-strength galvanized steel sheet during the heat treatment, the present invention adds the surface treatment before the heat treatment, and the surface of the steel sheet is covered with an alloy layer. Wherein the surface treatment is to cover the surface of the steel sheet with an alloy layer.
进一步地，氢在所述合金层中的高温溶解度比氢在奥氏体中的高温溶解度低2倍以上。Further, the high temperature solubility of hydrogen in the alloy layer is more than two times lower than the high temperature solubility of hydrogen in austenite.
进一步地，氢在所述合金层中的高温扩散系数比氢在奥氏体中的高温扩散系数低2倍以上。Further, the high temperature diffusion coefficient of hydrogen in the alloy layer is more than 2 times lower than the high temperature diffusion coefficient of hydrogen in austenite.
具体而言，为了让所述合金层能够起到阻碍氢在钢中吸收的作用，氢在所述合金层中的溶解度和扩散速度都要尽可能的小。试验结果表明，在目前的生产工艺条件下，如果氢在所述合金层中的高温溶解度比氢在奥氏体中的高温溶解度低2倍以上，即使所述合金层中的氢达到饱和状态，也能够极大减少氢在钢中的吸收。同时，如果氢在所述合金层中的高温扩散系数比在奥氏体中的高温扩散系数低2倍以上，那么氢扩散将主要被所述合金层阻碍，难以渗透到钢中。Specifically, in order for the alloy layer to function to hinder the absorption of hydrogen in the steel, the solubility and diffusion speed of hydrogen in the alloy layer are as small as possible. The test results show that under the current production process conditions, if the high temperature solubility of hydrogen in the alloy layer is more than 2 times lower than the high temperature solubility of hydrogen in austenite, even if the hydrogen in the alloy layer reaches a saturated state, It also greatly reduces the absorption of hydrogen in steel. Meanwhile, if the high temperature diffusion coefficient of hydrogen in the alloy layer is more than 2 times lower than the high temperature diffusion coefficient in austenite, hydrogen diffusion will be mainly hindered by the alloy layer and it is difficult to penetrate into the steel.
根据本发明所述冷轧高强热镀锌钢板，所述合金镀层厚度为10-100nm。所述合金层对氢的阻碍作用受到所述合金层厚度的影响。如果所述合金层的厚度超过10nm，同时氢在所述合金层中的溶解度和扩散速度满足以上要求，则氢在钢与所述合金层的界面位置的含量可以忽略不计。然而，所述合金层的厚度并不能无限增加。一方面所述合金层的厚度太厚会明显影响冷轧高强热镀锌钢板的性能，另一方面所述合金层的厚度太厚，也会削弱钢与热镀锌镀层的结合力。因此，本发明中所述合金层的厚度范围是10nm到100nm，优选的合金层厚度范围是50nm到100nm。According to the cold-rolled high-strength galvanized steel sheet according to the present invention, the alloy plating layer has a thickness of 10 to 100 nm. The barrier effect of the alloy layer on hydrogen is affected by the thickness of the alloy layer. If the thickness of the alloy layer exceeds 10 nm, and the solubility and diffusion rate of hydrogen in the alloy layer satisfy the above requirements, the content of hydrogen at the interface position between the steel and the alloy layer is negligible. However, the thickness of the alloy layer does not increase indefinitely. On the one hand, the thickness of the alloy layer is too thick to significantly affect the performance of the cold-rolled high-strength hot-dip galvanized steel sheet. On the other hand, the thickness of the alloy layer is too thick, which also weakens the bonding force between the steel and the hot-dip galvanized coating. Therefore, the thickness of the alloy layer in the present invention ranges from 10 nm to 100 nm, and the preferred alloy layer thickness ranges from 50 nm to 100 nm.
另一方面，本发明提供了一种冷轧高强热镀锌钢板的生产方法，其包括：钢水冶炼后获得板坯，将所述板坯进行加热，再经过粗轧、精轧、冷却、冷轧、表面处理、热处理、热镀锌和卷取；其中，所述表面处理是在所述钢板表面覆盖合金层；所述热处理过程包含过时效热处理。In another aspect, the present invention provides a method for producing a cold-rolled high-strength hot-dip galvanized steel sheet, comprising: obtaining a slab after molten steel smelting, heating the slab, and then performing rough rolling, finish rolling, cooling, and cooling Rolling, surface treatment, heat treatment, hot dip galvanizing and coiling; wherein the surface treatment is to cover the surface of the steel sheet with an alloy layer; the heat treatment process comprises an overaging heat treatment.
正如上文所述，为了避免冷轧高强热镀锌钢板在所述热处理过程中的氢吸 收，本发明在所述热处理之前增加了所述表面处理，在所述钢板表面覆盖一层合金层。其中，所述表面处理是在所述钢板表面覆盖合金层。As described above, in order to avoid hydrogen absorption of the cold-rolled high-strength galvanized steel sheet during the heat treatment, the present invention adds the surface treatment before the heat treatment, and the surface of the steel sheet is covered with an alloy layer. Wherein, the surface treatment is to cover the surface of the steel sheet with an alloy layer.
根据冷轧高强热镀锌钢板的生产方法，氢在所述合金层中的高温溶解度比氢在奥氏体中的高温溶解度低2倍以上。According to the method for producing a cold-rolled high-strength hot-dip galvanized steel sheet, the high-temperature solubility of hydrogen in the alloy layer is more than two times lower than the high-temperature solubility of hydrogen in austenite.
根据冷轧高强热镀锌钢板的生产方法，氢在所述合金层中的高温扩散系数比氢在奥氏体中的高温扩散系数低2倍以上。According to the method for producing a cold-rolled high-strength hot-dip galvanized steel sheet, the high-temperature diffusion coefficient of hydrogen in the alloy layer is more than two times lower than the high-temperature diffusion coefficient of hydrogen in austenite.
根据冷轧高强热镀锌钢板的生产方法，所述合金层对氢的阻碍作用受到所述合金层厚度的影响。如果所述合金层的厚度超过10nm，同时氢在所述合金层中的溶解度和扩散速度满足以上要求，则氢在钢与所述合金层的界面位置的含量可以忽略不计。然而，所述合金层的厚度并不能无限增加。一方面所述合金层的厚度太厚会明显影响冷轧高强热镀锌钢板的性能，另一方面所述合金层的厚度太厚，也会削弱钢与热镀锌镀层的结合力。因此，本发明中所述合金层的厚度范围是10nm到100nm，优选的合金层厚度范围是50nm到100nm。According to the production method of the cold-rolled high-strength hot-dip galvanized steel sheet, the hindrance of the alloy layer to hydrogen is affected by the thickness of the alloy layer. If the thickness of the alloy layer exceeds 10 nm, and the solubility and diffusion rate of hydrogen in the alloy layer satisfy the above requirements, the content of hydrogen at the interface position between the steel and the alloy layer is negligible. However, the thickness of the alloy layer does not increase indefinitely. On the one hand, the thickness of the alloy layer is too thick to significantly affect the performance of the cold-rolled high-strength hot-dip galvanized steel sheet. On the other hand, the thickness of the alloy layer is too thick, which also weakens the bonding force between the steel and the hot-dip galvanized coating. Therefore, the thickness of the alloy layer in the present invention ranges from 10 nm to 100 nm, and the preferred alloy layer thickness ranges from 50 nm to 100 nm.
根据冷轧高强热镀锌钢板的生产方法，所述热处理过程包含过时效热处理。为了消除钢种残余的部分氢原子，本发明在所述热处理工艺中增加了所述过时效热处理。所述过时效热处理的目的是使所述钢板中的氢原子扩散到所述钢板的表面，并及时去除。According to the method for producing a cold-rolled high-strength hot-dip galvanized steel sheet, the heat treatment process includes an overage heat treatment. In order to eliminate a portion of the hydrogen atoms remaining in the steel grade, the present invention adds the overage heat treatment in the heat treatment process. The purpose of the overaging heat treatment is to diffuse hydrogen atoms in the steel sheet to the surface of the steel sheet and remove them in time.
进一步地，所述过时效热处理的温度范围为200-300℃。为了让氢有足够的动力因素扩散出去，必须让所述钢板具有一定的温度，本发明规定所述过时热效处理的温度应当不低于200℃。然而，如果所述过时效热处理的温度太高，则对所述钢板的晶粒组织有不利影响，比如造成马氏体分解、贝氏体粗大、层片马氏体转变为针状马氏体、铁素体中析出碳化物等等。因此，本发明中规定了所述过时效热处理的温度不超过300℃，即所述过时效热处理的温度范围为200-300℃。Further, the temperature of the overage heat treatment ranges from 200 to 300 °C. In order for the hydrogen to have sufficient kinetic factors to diffuse out, the steel sheet must have a certain temperature, and the temperature of the outdated heat treatment of the present invention should be not lower than 200 °C. However, if the temperature of the overaging heat treatment is too high, the grain structure of the steel sheet is adversely affected, such as causing martensite decomposition, bainite coarsening, and lamellar martensite transformation into needle martensite. , precipitation of carbides in ferrite, and the like. Therefore, in the present invention, the temperature of the overaging heat treatment is not more than 300 ° C, that is, the temperature of the overaging heat treatment is in the range of 200 to 300 ° C.
根据冷轧高强热镀锌钢板的生产方法，所述过时效热处理时气氛中氢气含 量不超过1％，以保证扩散到钢板表面的氢能及时去除。According to the production method of the cold-rolled high-strength hot-dip galvanized steel sheet, the hydrogen content in the atmosphere during the overaging heat treatment is not more than 1%, so that the hydrogen diffused to the surface of the steel sheet can be removed in time.
根据冷轧高强热镀锌钢板的生产方法，所述过时效热处理的时间不少于30秒。氢在钢板中的扩散需要一定时间，冷轧高强热镀锌钢板的厚度范围一般为0.5mm到3mm，通过计算可知，氢的扩散时间至少需要30秒，本发明中规定所述过时效热处理的时间不少于30秒。According to the method for producing a cold-rolled high-strength hot-dip galvanized steel sheet, the time of the overaging heat treatment is not less than 30 seconds. The diffusion of hydrogen in the steel sheet takes a certain time, and the thickness of the cold-rolled high-strength galvanized steel sheet generally ranges from 0.5 mm to 3 mm. It is known from calculation that the diffusion time of hydrogen takes at least 30 seconds, and the overaging heat treatment is prescribed in the present invention. The time is no less than 30 seconds.
根据冷轧高强热镀锌钢板的生产方法，所述过时效热处理之后，所述钢板立刻进行所述热镀锌处理以使得让钢板在所述过时效热处理后不再吸收氢。According to the method for producing a cold-rolled high-strength hot-dip galvanized steel sheet, after the overaging heat treatment, the steel sheet is immediately subjected to the hot-dip galvanizing treatment so that the steel sheet does not absorb hydrogen after the overaging heat treatment.
本发明上述实施方式中的一个或多个技术方案至少具有如下一种或多种技术效果：One or more of the above-mentioned embodiments of the present invention have at least one or more of the following technical effects:
1、根据本发明实施方式提供的一种冷轧高强热镀锌钢板及其生产方法，所述冷轧高强热镀锌钢板的镀层与基板之间包含有一层合金层，合金层的厚度为10-100nm，氢在所述合金层中的高温溶解度比氢在奥氏体中的高温溶解度低2倍以上，氢在所述合金层中的高温扩散系数比氢在奥氏体中的高温扩散系数低2倍以上。所述生产方法包括：钢水冶炼后获得板坯，将所述板坯进行加热，再经过粗轧、精轧、冷却、冷轧、表面处理、热处理、热镀锌和卷取；其中，所述表面处理是在所述钢板表面覆盖合金层；所述热处理过程包含过时效热处理。通过上述方法解决了现有技术中冷轧高强热镀锌钢板中氢的含量大，易出现氢脆风险的技术问题，达到了降低冷轧高强热镀锌钢板中氢的含量，大大降低氢脆风险的技术效果。A cold-rolled high-strength galvanized steel sheet and a method for producing the same according to an embodiment of the present invention, wherein the cold-rolled high-strength galvanized steel sheet has an alloy layer between the plating layer and the substrate, and the alloy layer has a thickness of 10 -100 nm, the high temperature solubility of hydrogen in the alloy layer is more than 2 times lower than the high temperature solubility of hydrogen in austenite, and the high temperature diffusion coefficient of hydrogen in the alloy layer is higher than the high temperature diffusion coefficient of hydrogen in austenite. 2 times lower. The production method comprises: obtaining slab after molten steel smelting, heating the slab, and then performing rough rolling, finish rolling, cooling, cold rolling, surface treatment, heat treatment, hot-dip galvanizing and coiling; wherein The surface treatment is to cover the surface of the steel sheet with an alloy layer; the heat treatment process includes an overaging heat treatment. The above method solves the technical problem that the hydrogen content in the cold-rolled high-strength hot-dip galvanized steel sheet in the prior art is large and the risk of hydrogen embrittlement is easy to occur, and the hydrogen content in the cold-rolled high-strength hot-dip galvanized steel sheet is reduced, and the hydrogen embrittlement is greatly reduced. The technical effect of risk.
2、根据本发明实施方式，通过将所述过时效热处理的温度范围控制在200-300℃，达到让氢有足够的动力从钢板中扩散出去从而降低钢板中氢含量的技术效果。2. According to an embodiment of the present invention, by controlling the temperature range of the overaging heat treatment at 200-300 ° C, the technical effect of allowing hydrogen to have sufficient power to diffuse out of the steel sheet to reduce the hydrogen content in the steel sheet is achieved.
3、根据本发明实施方式，通过所述过时效热处理时气氛中氢气含量不超过1％，达到将扩散到钢板表面的氢及时去除的技术效果。3. According to an embodiment of the present invention, the hydrogen content in the atmosphere during the overaging heat treatment is not more than 1%, and the technical effect of timely removing the hydrogen diffused to the surface of the steel sheet is achieved.
4、根据本发明实施方式，通过所述过时效热处理之后，所述钢板立刻进 行所述热镀锌处理，达到钢板在过时效热处理后不再吸收氢从而降低钢板中氢含量的技术效果。4. According to an embodiment of the present invention, after the overaging heat treatment, the steel sheet is immediately subjected to the hot-dip galvanizing treatment to achieve a technical effect that the steel sheet no longer absorbs hydrogen after the overaging heat treatment to reduce the hydrogen content in the steel sheet.
实施例Example
为使本发明实施例的目的、技术方案和优点更加清楚，下面将对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。The present invention will be clearly and completely described in the following embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, and not all of them. An embodiment. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.
为了更清楚的阐述本发明，本申请提供了涉及一种冷轧高强热镀锌钢板的生产方法的实施例1-6以及对比例1-4，相关生产工艺参数以及实验数据如表1所示。In order to explain the present invention more clearly, the present application provides Examples 1-6 and Comparative Examples 1-4 relating to a method for producing a cold-rolled high-strength galvanized steel sheet, and related production process parameters and experimental data are shown in Table 1. .
本发明采用钢板中的氢含量用于评价钢板发生氢脆的风险，通常认为钢板中的氢含量小于1ppm时，发生氢脆的风险就在可以接受的范围内。The present invention uses the hydrogen content in the steel sheet to evaluate the risk of hydrogen embrittlement of the steel sheet. It is generally considered that the risk of hydrogen embrittlement is within an acceptable range when the hydrogen content in the steel sheet is less than 1 ppm.
表1.一种冷轧高强热镀锌钢板的生产工艺参数及实验数据Table 1. Production process parameters and experimental data of a cold-rolled high-strength hot-dip galvanized steel sheet
Figure PCTCN2018115296-appb-000001
Figure PCTCN2018115296-appb-000001
Figure PCTCN2018115296-appb-000002
Figure PCTCN2018115296-appb-000002
通过表1可知，采用本发明所述方法生产的冷轧高强热镀锌钢板中，氢的含量均低于1ppm，发生氢脆的风险就在可控范围内。As can be seen from Table 1, in the cold-rolled high-strength galvanized steel sheet produced by the method of the present invention, the hydrogen content is less than 1 ppm, and the risk of hydrogen embrittlement is within a controllable range.
本发明通过上述实施例和对比例，证明本发明所述方法能够解决现有技术中冷轧高强热镀锌钢板中氢的含量大，易出现氢脆风险的技术问题，达到了降低冷轧高强热镀锌钢板中氢的含量，大大降低氢脆风险的技术效果。Through the above embodiments and comparative examples, the invention proves that the method of the invention can solve the technical problem that the hydrogen content in the cold-rolled high-strength hot-dip galvanized steel sheet in the prior art is large, and the risk of hydrogen embrittlement is easy to occur, and the high-strength of cold rolling is achieved. The content of hydrogen in the hot-dip galvanized steel sheet greatly reduces the technical effect of the risk of hydrogen embrittlement.
尽管已描述了本发明的优选实施例，但本领域内的技术人员一旦得知了基本创造性概念，则可对这些实施例做出另外的变更和修改。所以，所附权利要求意欲解释为包括优选实施例以及落入本发明范围的所有变更和修改。Although the preferred embodiment of the invention has been described, it will be apparent to those skilled in the < Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and the modifications and
显然，本领域的技术人员可以对本发明实施例进行各种改动和变型而不脱离本发明实施例的精神和范围。这样，倘若本发明实施例的这些修改和变型属于本发明权利要求及其等同技术的范围之内，则本发明也意图包含这些改动和变型在内。It is apparent that those skilled in the art can make various modifications and variations to the embodiments of the invention without departing from the spirit and scope of the embodiments of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the embodiments of the invention.

Claims (13)

  1. 一种冷轧高强热镀锌钢板，其特征在于，冷轧高强热镀锌钢板的镀层与基板之间包含有一层合金层，所述合金层的厚度为10-100nm。A cold-rolled high-strength hot-dip galvanized steel sheet characterized in that an alloy layer is contained between a plating layer of a cold-rolled high-strength hot-dip galvanized steel sheet and a substrate, and the alloy layer has a thickness of 10 to 100 nm.
  2. 如权利要求1所述的一种冷轧高强热镀锌钢板，其特征在于，所述合金层的厚度优选为50-100nm。A cold-rolled high-strength galvanized steel sheet according to claim 1, wherein the alloy layer has a thickness of preferably 50 to 100 nm.
  3. 如权利要求1所述的一种冷轧高强热镀锌钢板，其特征在于，氢在所述合金层中的高温溶解度比氢在奥氏体中的高温溶解度低2倍以上。A cold-rolled high-strength galvanized steel sheet according to claim 1, wherein the high-temperature solubility of hydrogen in said alloy layer is more than two times lower than that of hydrogen in austenite.
  4. 如权利要求1所述的一种冷轧高强热镀锌钢板，其特征在于，氢在所述合金层中的高温扩散系数比氢在奥氏体中的高温扩散系数低2倍以上。A cold-rolled high-strength galvanized steel sheet according to claim 1, wherein a high-temperature diffusion coefficient of hydrogen in said alloy layer is more than two times lower than a high-temperature diffusion coefficient of hydrogen in austenite.
  5. 一种冷轧高强热镀锌钢板的生产方法，其特征在于，所述生产方法包括：钢水冶炼后获得板坯，将所述板坯进行加热，再经过粗轧、精轧、冷却、冷轧、表面处理、热处理、热镀锌和卷取；A method for producing a cold-rolled high-strength hot-dip galvanized steel sheet, characterized in that the production method comprises: obtaining a slab after molten steel smelting, heating the slab, and then performing rough rolling, finish rolling, cooling, and cold rolling , surface treatment, heat treatment, hot dip galvanizing and coiling;
    其中，所述表面处理是在所述钢板表面覆盖合金层；Wherein the surface treatment is to cover the surface of the steel sheet with an alloy layer;
    所述热处理过程包含过时效热处理。The heat treatment process includes an overage heat treatment.
  6. 根据权利要求5所述的方法，其特征在于，所述合金层的厚度为10-100nm。The method according to claim 5, wherein the alloy layer has a thickness of 10 to 100 nm.
  7. 根据权利要求6所述的方法，其特征在于，所述合金层的厚度优选为 50-100nm。The method according to claim 6, wherein the alloy layer has a thickness of preferably 50 to 100 nm.
  8. 根据权利要求5所述的方法，其特征在于，氢在所述合金层中的高温溶解度比氢在奥氏体中的高温溶解度低2倍以上。The method of claim 5 wherein the high temperature solubility of hydrogen in said alloy layer is more than two times lower than the high temperature solubility of hydrogen in austenite.
  9. 根据权利要求5所述的方法，其特征在于，氢在所述合金层中的高温扩散系数比氢在奥氏体中的高温扩散系数低2倍以上。The method according to claim 5, wherein the high temperature diffusion coefficient of hydrogen in the alloy layer is more than 2 times lower than the high temperature diffusion coefficient of hydrogen in austenite.
  10. 根据权利要求5所述的方法，其特征在于，所述过时效热处理的温度范围为200-300℃。The method of claim 5 wherein said overage heat treatment has a temperature in the range of from 200 to 300 °C.
  11. 根据权利要求5所述的方法，其特征在于，所述过时效热处理时气氛中氢气含量不超过1％。The method according to claim 5, wherein the hydrogen content in the atmosphere during the overaging heat treatment does not exceed 1%.
  12. 根据权利要求5所述的方法，其特征在于，所述过时效热处理的时间不少于30秒。The method according to claim 5, wherein the time of the overaging heat treatment is not less than 30 seconds.
  13. 根据权利要求5所述的方法，其特征在于，所述过时效热处理之后，所述钢板立刻进行所述热镀锌处理。The method according to claim 5, wherein said steel sheet is immediately subjected to said hot-dip galvanizing treatment after said overaging heat treatment.
PCT/CN2018/115296 2018-04-04 2018-11-14 Cold-rolled, high-strength, hot-dip galvanized steel sheet and production method thereof WO2019192181A1 (en)

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