EP0496423A1 - Tôle d'acier laminée et électroplaquée au nickel ayant des propriétés excellentes, en vue d'être déformée sous pression et d'être traitée par phosphatation ainsi que le procédé de fabrication de cette tôle - Google Patents

Tôle d'acier laminée et électroplaquée au nickel ayant des propriétés excellentes, en vue d'être déformée sous pression et d'être traitée par phosphatation ainsi que le procédé de fabrication de cette tôle Download PDF

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Publication number
EP0496423A1
EP0496423A1 EP92101186A EP92101186A EP0496423A1 EP 0496423 A1 EP0496423 A1 EP 0496423A1 EP 92101186 A EP92101186 A EP 92101186A EP 92101186 A EP92101186 A EP 92101186A EP 0496423 A1 EP0496423 A1 EP 0496423A1
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European Patent Office
Prior art keywords
steel sheet
cold
rolled steel
nickel
range
Prior art date
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EP92101186A
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German (de)
English (en)
Inventor
Toyofumi C/O Nkk Corporation Watanabe
Akihiko C/O Nkk Corporation Furuta
Tadashi C/O Nkk Corporation Ono
Yoshinori C/O Nkk Corporation Yomura
Shuuichi C/O Nkk Corporation Iwado
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JFE Engineering Corp
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NKK Corp
Nippon Kokan Ltd
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Publication of EP0496423A1 publication Critical patent/EP0496423A1/fr
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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
    • 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
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/48—After-treatment of electroplated surfaces

Definitions

  • the present invention relates to a nickel electroplated cold-rolled steel sheet excellent in press-formability and phosphating-treatability, and a method for manufacturing same.
  • a cold-rolled steel sheet for automobile or electric appliances is formed into a prescribed shape by means of a large-capacity press.
  • Annealing applied to the cold-rolled steel sheet for the purpose of recrystallization of crystal grains subjected to a serious strain during the cold rolling thereof is applicable either by a continuous annealing or a box annealing.
  • An ordinary low-carbon aluminum-killed steel has been used as a material for a mild cold-rolled steel sheet for deep drawing.
  • a low-carbon aluminum-killed steel containing silicon, manganese and phosphorus has been used as a material for a high-strength steel sheet for deep drawing.
  • the box annealing has been applied for the purpose of annealing the above-mentioned mild cold-rolled steel sheet for deep drawing and high-strength steel sheet for deep drawing.
  • the box annealing is characterized by a long heating time, a long cooling time, easy growth of crystal grains, and the availability of a cold-rolled steel sheet having a high Lankford value.
  • a box-annealed steel sheet is exposed to a high temperature for a longer period of time than a continuous-annealed steel sheet.
  • silicon, manganese and phosphorus contained in the box-annealed steel sheet are concentrated onto the surface of the steel sheet in the form of oxides. These oxides concentrated onto the surface of the steel sheet serve as a lubricant film during press forming.
  • the box-annealed steel sheet has a high Lankford value than that of the continuous-annealed steel sheet. Therefore, troubles such as press cracks hardly occur in the box-annealed steel sheet.
  • the elements contained in the steel sheet and the elements such as manganese concentrated onto the surface of steel sheet activate a phosphate film forming reaction, so that a dense and thin phosphate film is formed on the surface of the steel sheet.
  • the phosphate film has a function of improving paint adhesivity and corrosion resistance after painting of the steel sheet.
  • the known cold-rolled steel sheets suitable for the application of the continuous annealing treatment comprise an extra-low-carbon steel or a steel known as the inter-sticial free steel (hereinafter referred to as "IF steel").
  • An if steel is produced by adding at least one of titanium and niobium to an extra-low-carbon steel, and fixing carbon and nitrogen acting as solid-solution elements by means of these added elements, thereby making it possible to obtain a higher Lankford value with a short continuous annealing.
  • the Lankford value of a cold-rolled steel sheet for deep drawing subjected to the continuous annealing (hereinafter referred to as the "continuous-annealed cold-rolled steel sheet") is equal or even superior to the Lankford value of a cold-rolled steel sheet for deep drawing subjected to the conventional box annealing (hereinafter referred to as the "box-annealed cold-rolled steel sheet").
  • the continuous-annealed cold-rolled steel sheet is easily susceptible to cracks during the press forming, and when worked into a complicated shape, more susceptible to the galling than the box-annealed cold-rolled steel sheet.
  • Table 1 shows values of frictional coefficient ( ⁇ ) of the surface, Lankford values (r-value) and limiting drawing ratios (LDR) for the conventional continuous-annealed and box-annealed cold-rolled steel sheets, and Table 2 shows chemical compositions of the continuous-annealed and box-annealed cold-rolled steel sheets used in these studies.
  • Fig. 1 is a graph illustrating the relationship between a Lankford value and a limiting drawing ratio for a continuous-annealed cold-rolled steel sheet and a box-annealed cold-rolled steel sheet.
  • the mark “o” represents the box-annealed cold-rolled steel sheet
  • the mark “ ⁇ ” represents the continuous-annealed cold-rolled steel sheet.
  • the differences in the Lankford value and the limiting drawing ratio between the continuous-annealed and the box-annealed cold-rolled steel sheets are considered to be caused by the fact that a high frictional coefficient of the steel sheet surface as in the continuous-annealed cold-rolled steel sheet reduces lubricity between the steel sheet surface and the wrinkle inhibiting jig or the die, thus impairing smooth flow of the material in the press die.
  • Fig. 5 is an SEM (scanning electron microscope) micrograph showing the metallurgical structure of crystals of the phosphate film formed on the surface of the box-annealed cold-rolled steel sheet
  • Fig. 6 is an SEM micrograph showing the metallurgical structure of crystals of the phosphate film formed on the surface of the continuous-annealed cold-rolled steel sheet.
  • the phosphate film formed on the surface of the continuous-annealed cold-rolled steel sheet has coarse and larger crystal grains than those formed on the surface of the box-annealed cold-rolled steel sheet shown in Fig. 5.
  • the continuous-annealed cold-rolled steel sheet is therefore inferior in phosphating-treatability, paint adhesivity and corrosion resistance after painting to the box-annealed cold-rolled steel sheet.
  • the range of the plating weight of the plating layer of nickel and the like is so wide as from 1 to 500 mg/m2.
  • the plating weight of the plating layer of nickel and the like is large beyond the necessary level, or when particles of nickel and the like are not distributed at a certain distribution density, a crystal grain size suitable for forming a thin and dense phosphate film is not available, thus making it impossible to obtain an excellent paint adhesivity and an excellent corrosion resistance after painting.
  • 2-101,200 dated April 12, 1990 which comprises: a cold-rolled steel sheet; and a nickel plating layer, formed on the surface of said cold-rolled steel sheet, in which layer nickel particles are precipitated at a distribution density within a range of from 1 x 1012 to 5 x 1014/m2, the plating weight of said nickel plating layer being within a range of from 1 to 50 mg/m2 per surface of said cold-rolled steel sheet, each of said nickel particles comprising metallic nickel and non-metallic nickel, having a thickness within a range of from 0.0009 to 0.03 ⁇ m, adhering to the surface of said metallic nickel, and said nickel particles having particle size within a range of from 0.001 to 0.3 ⁇ m (hereinafter referred to as the "prior art 3").
  • prior art 3 it is possible to form a dense and uniform phosphate film having a crystal grain size within a certain range, thereby making it possible to obtain a cold-rolled steel sheet excellent in phosphating-treatability and corrosion resistance.
  • the prior art 3 permits reduction of frictional coefficient of the surface of the continuous-annealed cold-rolled steel sheet.
  • the number of initially precipitated nuclei of phosphate which is required for forming a dense and uniform phosphate film and giving a crystal grain size within a certain range by means of the phosphating treatment, is within a range of from 1 x 1010 to 5 x 1011/m2 in terms of the distribution density.
  • the plating weight of the nickel plating layer In order to limit the distribution density of nickel particles in the nickel plating layer within the range of from 1 x 1012 to 5 x 1014/m2 as described above, however, the plating weight of the nickel plating layer must be at least 5 mg/m2. According to the prior art 3, however, the plating weight of the nickel plating layer is disclosed to be within a range of from 1 to 50 mg/m2. Accordingly, when the plating weight of the nickel plating layer is under 5 mg/m2, it is impossible to achieve a distribution density of the nickel particles of at least 1 x 1012/m2. Therefore, the number of initially precipitated nuclei of phosphate cannot in some cases be kept within a desired range described above by the prior art 3, in which case an excellent phosphating-treatability of the steel sheet is unavailable.
  • non-metallic nickel is basically a metal oxide
  • non-metallic nickel oxide film having an average thickness of at least 0.005 ⁇ m on the steel sheet surface by subjecting the steel sheet to an anodic electrolytic treatment in an alkaline bath
  • non-metallic nickel oxide film having an average thickness larger than the above is formed on a portion of the steel sheet surface not having a nickel plating layer. Consequently, although press-formability is improved, the phosphate film contains more portions with a small deposited weight, thus resulting in a lower paint adhesivity and a poorer corrosion resistance after painting.
  • An object of the present invention is therefore to provide a nickel electroplated cold-rolled steel sheet for deep drawing excellent in press-formability and phosphating-treatability, suitable for the application of the continuous annealing treatment.
  • a nickel electroplated cold-rolled steel sheet excellent in press-formability and phosphating-treatability which comprises: a cold-rolled steel sheet consisting essentially of:
  • a method for manufacturing a nickel electroplated cold-rolled steel sheet excellent in press-formability and phosphating-treatability which comprises the steps of: preparing a steel ingot consisting essentially of:
  • said cold-rolled steel sheet may additionally contain any one of the following element(s):
  • the present invention was made on the basis of the above-mentioned findings. Now, the nickel electroplated cold-rolled steel sheet excellent in press-formability and phosphating-treatability of the present invention and the method for manufacturing same are described further in detail.
  • the chemical composition of the cold-rolled steel sheet of the present invention is limited within the above-mentioned range for the following reasons.
  • a carbon content of over 0.06 wt.% seriously impairs ductility of the cold-rolled steel sheet, thus leading to a poorer workability.
  • a carbon content of under 0.0005 wt.% results, on the other hand, in a longer refining time of steel, which is economically unfavorable.
  • Silicon and manganese are added to a high-strength steel sheet required to have a high press-formability. Silicon and manganese are elements which strengthen the solid-solution. Addition of silicon and manganese improves strength of the cold-rolled steel sheet without seriously impairing workability thereof. However, because of the easy oxidation of these elements, a silicon content of over 0.5 wt.% or a manganese content of over 2.5 wt.% causes oxidation of the steel sheet surface, thus impairing the surface appearance unique to the cold-rolled steel sheet. A silicon content of under 0.005 wt.% or a manganese content of under 0.05 wt.% results on the other hand in a longer refining time of steel, which is economically unfavorable.
  • Phosphorus has a function of improving strength of the cold-rolled steel sheet.
  • a phosphorus content of over 0.1 wt.% causes however, longitudinal cracks during the deep drawing of the cold-rolled steel sheet.
  • a phosphorus content of under 0.001 wt.% results on the other hand in a longer refining time of steel, which is economically unfavorable.
  • a lower sulfur content or a lower nitrogen content brings about an improved press-formability of the cold-rolled steel sheet.
  • a sulfur content of over 0.025 wt.% or a nitrogen content of over 0.005 wt.% is however economically unfavorable.
  • a sulfur content of under 0.005 wt.% or a nitrogen content of under 0.0005 wt.% results on the other hand in a longer refining time of steel, which is economically unfavorable.
  • Soluble aluminum is contained in steel as a residue of aluminum (Al) used as a deoxidizing agent.
  • Al aluminum
  • soluble aluminum has functions of fixing nitrogen and improving formability.
  • Titanium and niobium are additionally added as required in cases where a very high formability is required to the cold-rolled steel sheet. Titanium and niobium have a function of fixing carbon and nitrogen, thus making it possible to manufacture IF steel by adding titanium and/or niobium to steel.
  • the contents of titanium and niobium are dependent on the contents of carbon and nitrogen. With the contents of titanium and nitrogen of over 0.15 wt.%, respectively, a desired effect of fixing carbon and nitrogen is unavailable and economic demerits are encountered. When the contents of titanium and niobium are under 0.001 wt.%, respectively, the effect as described above is unavailable.
  • Boron has a function of preventing longitudinal cracks inevitably occurring in a cold-rolled steel sheet which comprises IF steel containing titanium and/or niobium. Addition of boron improves deep-drawability of the cold-rolled steel sheet. Therefore, boron is additionally added as required together with titanium and/or niobium. A boron content of over 0.003 wt.% leads however to a lower ductility of the cold-rolled steel sheet. With a boron content of under 0.0002 wt.%, on the other hand, a desired effect as described above is unavailable.
  • a nickel electroplating layer is formed on the surface of the continuous-annealed cold-rolled steel sheet having the above-mentioned chemical composition.
  • Nickel particles are precipitated in the nickel electroplating layer at a distribution density of at least 1 x 1012/m2, and the nickel electroplating layer has a plating weight within a range of from 5 to 60 mg/m2. The reason is as follows.
  • cathodes serving as precipitation nuclei for the precipitation of hopeite (Zn3(PO4)2) and phosphophyllite (Zn2Fe(PO4)2), which are phosphate crystals, are distributed at a certain density on the surface of the continuous-annealed cold-rolled steel sheet to form initially precipitated nuclei of phosphate known as local cells.
  • the number of cathodes distributed on the surface of the steel sheet is equal to the number of local cells formed under the effect of the difference in potential which is produced by elements concentrated on the steel sheet surface and nickel particles precipitated in the nickel electroplating layer formed on the steel sheet surface.
  • the crystal grains of the phosphate film should have a grain size within a certain range, and for this purpose, the number of initially precipitated nuclei of phosphate should have a distribution density within a range of from 1 x 1010 to 5 x 1011/m2. In order for the number of initially precipitated nuclei of phosphate to achieve a distribution density within the above-mentioned range, the nickel particles precipitated in the nickel electroplating layer should have a distribution density within a range of from 1 x 1012 to 5 x 1014/m2.
  • the plating weight of the nickel electroplating layer it is necessary to limit the plating weight of the nickel electroplating layer within a range of from 5 mg/m2 to 60 mg/m2 per surface of the cold-rolled steel sheet.
  • the plating weight of the nickel electroplating layer it is possible to adjust the distribution density of the nickel particles precipitated in the nickel electroplating layer to at least 1 x 1012/m2, and hence, to ensure the number of initially precipitated nuclei of phosphate necessary for the phosphating treatment, thereby reducing frictional coefficient.
  • the average grain size of phosphate crystals thus made available by limiting the plating weight of the nickel electroplating layer and the distribution density of the precipitated nickel particles is within a range of from 1 to 3 ⁇ m, which is equal to that of the phosphate crystals formed on the surface of the box-annealed cold-rolled steel sheet. This permits achievement of satisfactory paint adhesivity and corrosion resistance after painting.
  • a nickel oxide film having an average thickness within a range of from 0.0005 to 0.003 ⁇ m is formed on the surface of the nickel electroplating layer. The reason is as follows.
  • the plating weight of the nickel electroplating layer is not increased, but a nickel oxide film having an average thickness within a range of from 0.0005 to 0.003 ⁇ m, or more preferably, within a range of from 0.001 to 0.002 ⁇ m is formed on the surface of the nickel electroplating layer so as to increase lubricity of the steel sheet surface.
  • a nickel oxide film having an average thickness within a range of from 0.0005 to 0.003 ⁇ m, or more preferably, within a range of from 0.001 to 0.002 ⁇ m is formed on the surface of the nickel electroplating layer so as to increase lubricity of the steel sheet surface.
  • An average thickness of the nickel oxide film of under 0.0005 ⁇ m cannot provide a desired effect of reducing frictional coefficient.
  • the nickel oxide film is an electric insulator, an average thickness thereof of over 0.003 ⁇ m hinders smooth flow of electric current for causing precipitation of phosphate crystals. Therefore, when a nickel oxide film is formed through an anodic electrolytic treatment in a neutral or alkaline bath, if a bath concentration is high or an electric current is large, a thick nickel oxide film is formed, not only on the surface of the nickel electroplating layer, but also on the surface portions of the steel sheet not covered with the nickel electroplating layer. This reduces the number of initially precipitated nuclei of phosphate, leading to coarser crystal grains of phosphate, thus preventing formation of a dense phosphate film. For this reason, the average thickness of the nickel oxide film should be limited within a range of from 0.0005 to 0.003 ⁇ m, or more preferably, from 0.001 to 0.002 ⁇ m.
  • the above-mentioned nickel electroplated cold-rolled steel sheet of the present invention is manufactured as follows.
  • a steel ingot having a chemical composition within the above-mentioned range of the present invention is prepared. Then, the steel ingot is hot-rolled to prepare a hot-rolled steel sheet.
  • the hot-rolled steel sheet is cold-rolled at a reduction ratio within a range of form 60 to 85% to prepare a cold-rolled steel sheet.
  • the reduction ratio in the cold-rolling should be limited within the range of from 60 to 85%. With a reduction ratio of under 60% or over 85% in the cold-rolling, a sufficient deep-drawability of the cold-rolled steel sheet is unavaialble.
  • the thus prepared cold-rolled steel sheet is subjected to a continuous annealing treatment which comprises heating the cold-rolled steel sheet to a recrystallization temperature and then slowly cooling same.
  • the cold-rolled steel sheet is heated to a recrystallization temperature, and held at this temperature for a period of time within a range of from three to ten minutes. Then, the thus heated cold-rolled steel sheet is slowly cooled to a temperature of about 50°C at a cooling rate of up to 5°C/sec appropriately selected depending upon the grade of steel.
  • Another exemplification of the continuous annealing treatment in the present invention is as follows.
  • the cold-rolled steel sheet is heated to a recrystallization temperature, and held at this temperature for a period of time within a range of from three to ten minutes.
  • thus heated cold-rolled steel sheet is rapidly cooled to a temperature of up to 450°C at a cooling rate of at least 10°C/sec.
  • the steel sheet is subjected to an overaging treatment at a temperature within a range of from 250 to 400°C for a period of time within a range of from one to three minutes.
  • the steel sheet is cooled to a temperature of up to 50°C.
  • the cold-rolled steel sheet is thus subjected to the continuous annealing treatment because of the possibility of reducing the operation time, the availability of uniformity in quality, and the potential improvement of product yield and productivity.
  • the thus continuous-annealed cold-rolled steel sheet is subjected to a continuous nickel electroplating treatment in an acidic electroplating bath to form, on at least one surface of the cold-rolled steel sheet, a nickel electroplating layer having a plating weight within a range of from 5 to 60 mg/m2 per surface of the cold-rolled steel sheet, in which layer nickel particles are precipitated at a distribution density of at least 1 x 1012/m2.
  • the nickel particles may be precipitated on the surface of the cold-rolled steel sheet by a substitution method which comprises immersing the cold-rolled steel sheet in an acidic plating bath, but in order to cause stable precipitation of the nickel particles at a constant distribution density, the electroplating treatment should by employed.
  • the cold-rolled steel sheet on at least one surface of which the nickel electroplating layer has thus been formed is immersed into a neutral bath or an alkaline bath, or is subjected to an anodic electrolytic treatment in the neutral bath or the alkaline bath.
  • a nickel oxide film having an average thickness within a range of from 0.0005 to 0.003 ⁇ m is thus formed on the surface of the nickel electroplating layer.
  • An aqueous solution of 10 g/l sodium carbonate (Na2CO3) is applicable as an alkaline bath.
  • the surface of the cold-rolled steel sheet is cleaned by a pickling as required.
  • the pickling is applied because a continuous annealing equipment is in many cases provided with a direct heating furnace on the entry side and a rapid cooling apparatus such as a water coiling device and an air/water cooling device in a rapid cooling zone in the middle so that the increase in the dew point of the atmospheric gas during the heating produces an iron oxide film on the steel sheet surface, and this may prevent the nickel particles from being precipitated in a desirable state.
  • Steels B to G each having a chemical composition as shown in Table 2 were refined, and then slabs were prepared from the respective steels B to G by the continuous casting method. Then, the thus prepared slabs were hot-rolled to prepare respective hot-rolled steel sheets having a prescribed thickness.
  • the finishing temperature of each of the hot-rolled steel sheets was a temperature of at least the Ar3 transformation point of each of the steels, and the coiling temperature in the hot-rolling was 730°C for the steels B to E and G, and 560°C for the steel F. Then, the hot-rolled steel sheets were subjected to the pickling by the hydrochloric acid pickling method to remove scale from the surfaces of the hot-rolled steel sheets.
  • the pickled hot-rolled steel sheets were cold-rolled under the conditions as shown in Table 4 to prepare respective cold-rolled steel sheets having a thickness within a range of from 0.8 to 1.0 mm.
  • the cold-rolled steel sheets were subjected to a continuous annealing treatment under the conditions as shown in Table 4.
  • the thus continuous-annealed cold-rolled steel sheets were immersed in an acidic bath comprising hydrochloric acid as shown in Table 3 to apply a pickling under the conditions as shown in Table 3.
  • each of the pickled cold-rolled steel sheets was subjected to a continuous nickel electroplating treatment in a nickel electroplating bath as shown in Table 3 under the conditions as shown also in Table 3.
  • the cold-rolled steel sheet having the nickel electroplating layer formed thereon was subjected to an anodic electrolytic treatment in an aqueous solution of sodium hydrogencarbonate (NaHCO3) under the conditions as shown in Table 3 to form a nickel oxide film on the surface of the nickel electroplating layer.
  • NaHCO3 sodium hydrogencarbonate
  • samples of the nickel electroplated steel sheet outside the scope of the present invention (hereinafter referred to as the "samples for comparison") Nos. 1 to 13 were prepared by the use of the steels D and E each having a chemical composition within the scope of the present invention as shown in Table 2.
  • the samples for comparison Nos. 1 to 13 had a plating weight of the nickel electroplating layer outside the scope of the present invention or an average thickness of the nickel oxide film outside the scope of the present invention as shown in Table 5.
  • a test piece having a size of 30 mm x 200 mm was cut out from each of the samples of the invention Nos. 1 to 12 and the samples for comparison Nos. 1 to 13.
  • the surface roughness was imparted to the bottom surface of the pressing member in the direction at right angles to the sliding direction by means of diamond particles having a particle size of about 3 ⁇ m.
  • a plurality of disks having various diameters were cut out from each of the samples of the invention Nos. 1 to 12 and the samples for comparison Nos. 1 to 13. Then, these disks were drawn by means of a punch having a diameter of 50 mm. The ratio of the maximum disks diameter, in which cracks had not been produced on the disk, to the punch diameter was determined as a limiting drawing ratio. When measuring the limiting drawing ratio, a commercially available anticorrosive oil was smeared as a lubricant on the disk and the punch.
  • Each of the samples of the invention Nos. 1 to 12 and the samples for comparison Nos. 1 to 13 was immersed for 15 seconds in a phosphating treatment solution (manufactured by Japan Perkerizing Co., Ltd.; PB-3030), then rinsed and dried.
  • the surface of each of the samples of the invention and the samples for comparison thus immersed in the phosphating treatment solution was observed by means of a scanning type electron microscope to measure the number of initially precipitated nuclei of phosphate.
  • each of the samples of the invention and the samples for comparison was immersed in the above-mentioned phosphating treatment solution for 120 seconds to form a phosphate film completely on the surface of the steel sheet, and was observed by means of a scanning type electron microscope to measure the grain size of phosphate crystal grains and the appearance of the phosphate film.
  • the appearance of the phosphate slim was evaluated in accordance with the following criteria:
  • the phosphate film was peeled off by the reverse electrolysis to determine the deposited amount of the phosphate film from the difference in weight between before and after peeloff.
  • the distribution density of nickel particles was measured by extracting nickel precipitated on the steel sheet surface by the application of the extraction replica method, and then observing by means of a transmission type electron microscope. Measurement of the average thickness of the nickel oxide film was conducted by the application of the Anger electron spectroscopic method.
  • the samples of the invention Nos. 1 to 12 of which the plating weight of the nickel electroplating layer, the distribution density of nickel particles and the average thickness of the nickel oxide film were within the scope of the present invention, showed satisfactory results of tests and were excellent in press-formability and phosphating-treatability.
  • the sample for comparison No. 1 in contrast, having a low plating weight of the nickel electroplating layer outside the scope of the present invention and a low distribution density of nickel particles outside the scope of the present invention, showed a high frictional coefficient and a large grain size of phosphate crystal grains resulting in inferior press-formability and phosphating-treatability.
  • the samples for comparison Nos. 12 and 13 having a large plating weight of the nickel electroplating layer outside the scope of the present invention and a low distribution density of nickel particles outside the scope of the present invention, showed a large grain size of phosphate crystal grains, hence an inferior phosphating-treatability.
  • Fig. 2 is a graph illustrating the effect of the plating weight of the nickel electroplating layer on the number of initially precipitated nuclei of phosphate, the distribution density of nickel particles, frictional coefficient and the grain size of crystals of the phosphate film, for the examples of the present invention and the examples for comparison outside the scope of the present invention.
  • the mark “o” represents the sample of the invention, and the mark " o " represents the sample for comparison.
  • the range of the grain size of crystals of the phosphate film formed on the surface of the nickel electroplated cold-rolled steel sheet prepared from the steel H and the range of the frictional coefficient are indicated by the arrows. It is understood from fig.
  • the number of initially precipitated nuclei of phosphate, the distribution density of nickel particles, the frictional coefficient and the grain size of phosphate crystal grains are as satisfactory as the results available in the box-annealed cold-rolled steel sheet.
  • Fig. 3 is a graph illustrating the relationship between the Lankford value and the limiting drawing ratio, for the examples of the present invention and the examples for comparison outside the scope of the present invention.
  • the mark “o” represents the sample of the invention
  • the mark “ o " represents the sample for comparison
  • the mark “ ⁇ ” represents a continuous-annealed cold-rolled steel sheet not nickel-electroplated. It is understood from Fig. 3 that there are differences in the Lankfrod value and the limiting drawing ratio between the examples of the invention and the examples for comparison.
  • Fig. 4 is a graph illustrating the effect of the average thickness of the nickel oxide film on the grain size of crystals of the phosphate film and the frictional coefficient, for the examples of the present invention and the examples for comparison outside the scope of the present invention.
  • the mark “o” represents the sample of the invention, and the mark “ o " represents the sample for comparison.
  • the range of the grain size of crystals of the phosphate film formed on the surface of the nickel electroplated cold-rolled steel prepared from the steel F and the range of the frictional coefficient are indicated by the arrows. It is understood from fig.

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  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
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  • Metallurgy (AREA)
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EP92101186A 1991-01-25 1992-01-24 Tôle d'acier laminée et électroplaquée au nickel ayant des propriétés excellentes, en vue d'être déformée sous pression et d'être traitée par phosphatation ainsi que le procédé de fabrication de cette tôle Withdrawn EP0496423A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP25695/91 1991-01-25
JP3025695A JPH04247849A (ja) 1991-01-25 1991-01-25 プレス成形性および燐酸塩処理性に優れた冷延鋼板およびその製造方法

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EP0496423A1 true EP0496423A1 (fr) 1992-07-29

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EP92101186A Withdrawn EP0496423A1 (fr) 1991-01-25 1992-01-24 Tôle d'acier laminée et électroplaquée au nickel ayant des propriétés excellentes, en vue d'être déformée sous pression et d'être traitée par phosphatation ainsi que le procédé de fabrication de cette tôle

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EP (1) EP0496423A1 (fr)
JP (1) JPH04247849A (fr)
KR (1) KR920014947A (fr)
CN (1) CN1065690A (fr)
AU (1) AU638371B2 (fr)
BR (1) BR9200205A (fr)
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008000583A1 (fr) * 2006-06-28 2008-01-03 Siemens Aktiengesellschaft Tôle métallique et procédé de fabrication associé
WO2008015051A1 (fr) * 2006-08-02 2008-02-07 Robert Bosch Gmbh Procédé de phosphatation d'une couche métallique
WO2015185072A3 (fr) * 2013-10-25 2016-03-17 GM Global Technology Operations LLC Tôle en acier composite
US20180274069A1 (en) * 2015-09-25 2018-09-27 Nippon Steel & Sumitomo Metal Corporation Steel sheet
CN114829679A (zh) * 2019-12-17 2022-07-29 Posco公司 磷酸盐处理性优异的高强度冷轧钢板及其制造方法

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2810245B2 (ja) * 1991-01-25 1998-10-15 日本鋼管株式会社 プレス成形性および燐酸塩処理性に優れた冷延鋼板およびその製造方法
JP3300673B2 (ja) * 1998-07-01 2002-07-08 日本パーカライジング株式会社 鋼線材にりん酸塩皮膜を迅速に形成する方法および装置
CN100376707C (zh) * 2003-04-01 2008-03-26 江苏江南铁合金有限公司 低硅钛铁
JP3918787B2 (ja) * 2003-08-01 2007-05-23 住友金属工業株式会社 低炭素快削鋼
JP4893540B2 (ja) * 2007-09-03 2012-03-07 住友金属工業株式会社 ダル鋼板及びその製造方法
KR101989219B1 (ko) * 2012-04-19 2019-06-13 닛폰세이테츠 가부시키가이샤 강박 및 그 제조 방법
KR102493773B1 (ko) * 2020-12-21 2023-01-30 주식회사 포스코 인산염 반응성이 우수한 강판 및 이의 제조방법

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4035248A (en) * 1975-06-23 1977-07-12 Nippon Steel Corporation Method for the manufacture of a steel sheet having a Ni-diffused base layer which is treated with a chromic acid

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6176621A (ja) * 1984-09-25 1986-04-19 Kawasaki Steel Corp りん酸塩処理性と成形性に優れた極低炭素冷延鋼板の製造方法
JPH06104918B2 (ja) * 1988-10-07 1994-12-21 日本鋼管株式会社 リン酸塩処理性および耐食性に優れた冷延鋼板
JPH02163344A (ja) * 1988-12-15 1990-06-22 Kawasaki Steel Corp 耐型かじり性に優れた深絞り用冷延鋼板
JPH0756050B2 (ja) * 1989-05-30 1995-06-14 新日本製鐵株式会社 連続焼鈍による非時効・高焼付硬化・プレス加工用高強度冷延鋼板の製造方法
JP2810245B2 (ja) * 1991-01-25 1998-10-15 日本鋼管株式会社 プレス成形性および燐酸塩処理性に優れた冷延鋼板およびその製造方法

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4035248A (en) * 1975-06-23 1977-07-12 Nippon Steel Corporation Method for the manufacture of a steel sheet having a Ni-diffused base layer which is treated with a chromic acid

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, unexamined applications, C field, vol. 13, no. 362, August 14, 1989, THE PATENT OFFICE JAPANESE GOVERNMENT page 67 C 625 *
PATENT ABSTRACTS OF JAPAN, unexamined applications, C field, vol. 14, no. 304, June 29, 1990, THE PATENT OFFICE JAPANESE GOVERNMENT page 167 C 734 *
PATENT ABSTRACTS OF JAPAN, unexamined applications, C field, vol. 5, no. 195, December 11, 1981, THE PATENT OFFICE JAPANESE GOVERNMENT page 28 C 83 *
PATENT ABSTRACTS OF JAPAN, unexamined applications, C field, vol. 5, no. 195, December 11, 1981, THE PATENT OFFICE JAPANESE GOVERNMENT page 29 C 83 *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008000583A1 (fr) * 2006-06-28 2008-01-03 Siemens Aktiengesellschaft Tôle métallique et procédé de fabrication associé
WO2008015051A1 (fr) * 2006-08-02 2008-02-07 Robert Bosch Gmbh Procédé de phosphatation d'une couche métallique
WO2015185072A3 (fr) * 2013-10-25 2016-03-17 GM Global Technology Operations LLC Tôle en acier composite
US20180274069A1 (en) * 2015-09-25 2018-09-27 Nippon Steel & Sumitomo Metal Corporation Steel sheet
US11180835B2 (en) 2015-09-25 2021-11-23 Nippon Steel Corporation Steel sheet
CN114829679A (zh) * 2019-12-17 2022-07-29 Posco公司 磷酸盐处理性优异的高强度冷轧钢板及其制造方法
EP4079944A4 (fr) * 2019-12-17 2023-01-25 Posco Feuille d'acier laminée à froid à haute résistance présentant une excellente aptitude à la phosphatation et procédé de fabrication associé
CN114829679B (zh) * 2019-12-17 2024-01-05 Posco公司 磷酸盐处理性优异的高强度冷轧钢板及其制造方法

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JPH04247849A (ja) 1992-09-03
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AU1013792A (en) 1992-08-06
CN1065690A (zh) 1992-10-28
CA2058678A1 (fr) 1992-07-26
BR9200205A (pt) 1992-10-06
KR920014947A (ko) 1992-08-26

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