CA1309055C - Plated steel sheet having excellent coating performance - Google Patents
Plated steel sheet having excellent coating performanceInfo
- Publication number
- CA1309055C CA1309055C CA000539351A CA539351A CA1309055C CA 1309055 C CA1309055 C CA 1309055C CA 000539351 A CA000539351 A CA 000539351A CA 539351 A CA539351 A CA 539351A CA 1309055 C CA1309055 C CA 1309055C
- Authority
- CA
- Canada
- Prior art keywords
- coating
- alloy
- upper layer
- steel sheet
- boron
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- 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
- 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
-
- 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
-
- 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
- C25D5/10—Electroplating with more than one layer of the same or of different metals
Abstract
Abstract When a single-layer plated steel sheet comprising a coating of pure Zn or a Zn alloy (for example, a Zn-Fe alloy, a Zn-Ni alloy, etc.) is used in a cationic electrodeposition coating coating method e.g. for coating components of automobile bodies, craterings are generated on a coating film at the time of the electrodeposition coating thus impairing the coating appearance.
Accordingly, this invention makes it possible to stably restrain the generation of craterings on a coating film by providing a coating comprising Fe containing boron (B) or a coating comprising an Fe-Zn alloy having a boron-containing Fe percentage of 50% or more, on the surface of the coating of the pure Zn- or a Zn alloy-plated steel sheet. The boron content in the Fe coating or the Fe-Zn alloy coating may be preferably controlled to 0.001 to 3 wt.%. The coating weight may be preferably controlled to 0.5 to 10 g/m2 (per one side) in the case of the Fe coating, and 0.2 to 8 y/m2 (per one side) in the case of the Fe-Zn alloy coating.
Accordingly, this invention makes it possible to stably restrain the generation of craterings on a coating film by providing a coating comprising Fe containing boron (B) or a coating comprising an Fe-Zn alloy having a boron-containing Fe percentage of 50% or more, on the surface of the coating of the pure Zn- or a Zn alloy-plated steel sheet. The boron content in the Fe coating or the Fe-Zn alloy coating may be preferably controlled to 0.001 to 3 wt.%. The coating weight may be preferably controlled to 0.5 to 10 g/m2 (per one side) in the case of the Fe coating, and 0.2 to 8 y/m2 (per one side) in the case of the Fe-Zn alloy coating.
Description
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SP~CIFICATION
excellent coating perfor~ance Technical field .
This invention relates to a plated steel shee-t excellent in the appearance of a coating ~hen applied in such a use that cationic electrodeposition coating is carried out as in the case of components for automobile bodies.
_ac~ground art In North America, Canada, North Europe and elsewhere, rock sa t is sprayed in winter to prevent roads from free~ing, and therefore steel sheets used for the co~ponents of automobile bodies are required to have excellent corrosion-resisting performance. For thi~
reason, in such a use, there have been recently applied pure zinc-plated steel sheets or zinc alloy-plated steel sheets (for example, Zn-Fe alloy-plated steel sheets, Zn-Ni alloy-plated steel sheets, and so forth) having excellent corrosion resistance.
However, there has been a problem that, in the case of a single-layer coating, these plated steel sheets may bear craterings generated on a coating film when the cationic electrodeposition coating is carried out after pho~phating, to give poor appearance of the coating.
Now, as a steel sheet that has solved the problem of the coating appearance, a double-layer plated steel sheet has been p~oposed, wherein an Fe coating that can achieve a good electrodeposition coating performance is further applied on a pure Zn or Zn alloy coating. Conventionally kno~n stee1 sheets of this type may include those wherein an upper layer comprises an Fe-Zn alloy coating having Fe content of 60 to 9o wt.~, and -those wherein an upper layer comprises an Fe coating, and it is true that the application of the cationic electrodeposition coating on these double-layer plated steel shee-ts may result in generation of a decreased number of craterings on a coating film and can improve the coating appearance.
~ owever, in order to lessen the generation of craterings on a coating film by providing the Fe-Zn alloy coating having Fe content of 60 to 90 wt.%, the coating weight must be made not less than 5 g/m2 (per one sidel, necessarily resulting in higher production cost.
Moreover, this Fe alloy coating is so hard and brittle that an infinite number of crack may be formed when a plated steel sheet is worked into a component, with the result that the lower layer i9 exposed at the cracked portion. ~herefore, when the electrodeposition coating is carried out, it ollows that the electrodeposition coating is directly applied on the lower layer, and also that craterings are liable to be generated on the coating film.
On the other hand, in the case of the Fe coating, which is softer than the Fe-Zn alloy coa-ting, no crack i5 generated even when the plated steel sheet is worked into a co~ponent, and only a little cratering is generated on the coating film. However, if the coating weight is less than 3 g/m ~per one side), there is seen variation in the quantity of the generation of craterings. Although the variation factor has not been made clear, -this i5 presumably because the covering rate in the upper layer coating relative to the lower layer coating is so poor, or the purity of the upper layer coating is so high, that large crystals of phosphate may tend to be for~ed during phosphating which is a pre-treatm~nt for the electrodeposition coating, and, as a re~ult, the rate of ~$~
covering by the phosphate crystals on the surface of a coating may be lowered and also the variation in the coveriny rate may be caused to bring about a difference in the electrolytic conduction for electrodepos.ition coating, between the phosphate deposited portion and non-deposited portion. Therefore, in order to lessen the generation of craterings on a coa~ing film by providing the Fe coating, the coatin~ wei~ht must be 3 g~m (per one side), also necessarily resulting in higher production cost.
Taking account of the fact that the electrodeposition coating performance has not been perfect even in the double-layer plated steel sheet obtained by applying the Fe coating on the pure Zn coating or Zn alloy coating as mentioned above, this invention aims at providing a plated steel sheet that has been improved the electrodeposition coating performance and yet can achieve lower production C05t.
Disclosure o This invention provides a plated steel sheet which is comprised of a plated steel sheet comprising a steel sh~et;
a lower layer coating of pure Zn or a Zn alloy, provided on the steel sheet, and an upper layer coating of an Fe-Zn alloy having an Fe percentage of 50 wt.% or more, provided on said lower layer coating, said upper layer coating containing from about O.O01 to 3 wt.~ of boron, thereby making it possible to prevent craterings being generated on a coating film and lessen the upper layer coating weight.
The reason why the plated steel sheet of this invention can have an excellent electrodeposition coating - performance i~ presumed to be that the presence of boron added to a bath at the time of the plating ~or the upper layer can improve the uniformitr of the electrodeposition to give a uniform coating, and also that the boron contained in the upper layer can serve as a nucleus at the ~, ~
. .
1 3~,~J6~ ~_! r~
time of the deposition of phosphate when a phosphating is applied as a pre-treatment for the electrodeposition coating, to form a fine and dense phosphate coating, and, as a result, the electrolytic conduction on the entire surface of a steel sheet becomes uniform, whereby a coating material can be uniformly electrodeposited at the time the electrodepositior~ coating is carried out, and thus the generation of craterings can be stably restrained.
Best mode for workin~ the invention The plated steel sheet of this invention can restrain the generation of craterings in a coating film even when the coating weight is not more than 3 g/m2 per one side in the case the upper layer comprises the boron-containing Fe coating, or even when the coating weight is not more than 5 g/m2 per one side in the case the upper layer comprises the above element-cor.taining Fe alloy coating, This is presumably because, even if the coating weight is small, the upper layer can cover the lower layer so excellently that the rate of covering of the lower layer by the upper layer can be improved.
In the case the upper layer comprises the Fe-Zn alloy coatlng, it has been conventionally i~possible to lessen the generation of craterings in a coating film unless Fe content is controlled to less than 60 to 100 wt.%. However, the presence of boron contained makes it possible to lessen the generation of craterings in a coating film even if the Fe content is decreased to 50 to 100 wt.%. This is presumably because of the above mentioned effect of improving the phosphating performance, and once the Fe content can be decreased like this, the difference in the corrosion potential between the upper layer and the lower layer becomes smalll whereby the corrosion resistance of the coa-tings as a whole for a long period can be improved.
The amount of boron contained in the upper layer may preferably be controlled to 0.001 to 3 wt.%. This is because the boron amount of less -than 0.001 wt.~ may result in no difference ~rom an upper layer containing no boron in respect of the generation of craterings and variation thereof in the electrodeposition coating, and the boron amount more than 3 wt.% may result in saturation of the effect so that it is meaningless to make the amount larger than that.
The covering weight on the upper layer (per one side) may be preferably controlled to 0.5 to 10 gtm2 in the case of the boron-containing Fe coating, and 0.2 to ~
g/m2 in the case of the Fe alloy coating. This is because the weight of less than 0.5 g/m2 or 0.2 g/m2 may make it impossible to achieve perfect covering of the lower layer to bring about the generation of craterings in a coating film to be caused by the exposure of the lower layer at the time of the electrodeposition coating, and the weight more than 10 g/m2 or 3 g/m2 may result in saturation of the ef~ect of restraining the generation of craterin~s in a coating film so that it is unnecessary to make the coating weight larger than that. Meanwhile, in the case of the conventional upper layer coating comprising the Fe-Zn alloy containing no boron, the effect of restraining the generation of craterings in a coating film has been saturated when the weight is 10 g 10/m2 g. The effect by virtue of the addition of boron can be seen also in this - point, in respect of the decrease in the coating weight.
In order to codeposit boron into the upper layer in an amount of 0.001 to 3 wt.% according to electroplating, th~ plat.ing may be carried out by adding one or more of boron compound(s) such as boric acid, metaboric acid, water soluble metaborate, water soluble tetraborate and tetrafluorsborate to an ordinary Fe plating bath or a plating bath of an Fe alloy such as an Fe-Zn alloy and an , ~., ~
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~;
Fe-Ni alloy, and adjusting the pH of the bath to 1 to 3.
The steel sheet according to this in~ention can improve the performance in the electrocleposition coating of a pure Zn-plated or Zn alloy-plated steel sheet.
However, in the case the lower layer comprises an Zn alloy coating of a Zn-Ni or Zn-Fe alloy, the generation of craterings can be restrained even with imclusion of a trace amount of o~e or more of elements su~h as Ni ~in respect of the Zn-Fe alloy), Fe ~in respect of the Zn-Ni alloy), Co, Cr, Mn, Mo and Ti. In the case the lower layer comprises a pure Zn coating, it can be also restrained even with respect to coatings obtained by carrying out electroplating, vacuum deposition or hot dipping. Further, in the case the upper layer comprises the Zn alloy coating, it can be also restrained even with respect, in addition to the coatings formed by the above methods, to those which are alloyed into a Zn-Fe alloy by thermal diffusion after carrying out hot dip ~inc coating or vacuum zinc deposition as in the case of an alloyed zinc-plated steel sheet.
This invention will be described below more specifically by ~xamples.
Example 1 On a cold rolled steel sheet of 0.8 mm thick, usual treatments of degreasing and acid pickling were applied to make its surface clean. Therea~ter, a lower layer coating comprising pure Zn, an Zn-Fe alloy or Zn-Ni alloy was first provided according to electroplating under the conditions as shown in Table 1, and next an upper layer coating comprising Fe or Fe-B was provided on it according to the same plating method.
Subsequently, from the thus plated steel sheet, samples were collected by 10 sheets per each plating condition, which were treated with a commercially available phbsphating solution (Bondelite #3030*; produced by Nippon Parker Co.), followed by carrying out cationic *Trade mark . , ' ' , electrodeposition coating to examine the number of craterings generated on the coatings after drying by baking. In the electrodeposition, ~lcon* #9000 (produced by Kansai Paint Co., Ltd.) was used as a coating material, which was electrodeposited according to an instantaneous voltage-increasing ~ethod (the so-called "dokan" method) under 300 V to have a coating film thickness of 25 um, and the baking was carried out at 1~0C for 20 minutes. The number of craterings generated in the coating film when provided with an Fe-B coating as the upper layer is shown in Table 2.
As will be clear ~rom Table 2, the steel sheets of this invention, provided with an Fe-B coating as the upper layer, show less generation o~ craterings and variation thereof than those in conventional double-layer plated steel sheets provided with an upper layer Zn coating and having a good electrodepo~ition coating perfor~ance, even with a lower layer comprising a pure Zn coating or a Zn alloy coating.
*Trade mark ~ J~P~ ~
Table 1 Conditions for lower layer coating _ _ ... .
Pure Zn coating Zn-Fe alloy coating Plating bath composition:
Zinc sulfate 240 g/lit Ferrous sulfate ,'80 g/lit Sodium sulfate 75 g/lit Zinc sulfate 75 g/lit Sodium sulfate 85 g/lit Plating conditions:
pH 1.5 pH 1.6 Bath temperature 50C Bath temperature 50C
Current density 20 A/dm2 Current density 40 A/dm Others:
Fe content 15 to 20 wt.%
- Coating weight 20 g/m2 _ (~E~r one side) Conditions for lower layer coating (Cont'd) Zn-Ni alloy coating Plating bath composition:
Nickel sulfate 260 g/lit Zinc sulfate 150 g/lit Sodium sulfate 70 g/lit Plating conditions:
pH 2.0 Bath temperature 55C
Current densit-y 40 A/dm Others:
Ni content 11 to 12 wt.%
Coating weight 20 g/m2 (~er one side) . ~ .. . .
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Table 1 (cont'd) Condit.ions for upper layer coating _ Fe-B coating _ Plating bath composition:
Ferrous sulfate 250 g/lit Sodium sulfate 70 g/lit Tartaric acid 3 g/lit Sodium metaborate 10 to 50 g/lit Plating conditions:
Current density 20 to 30 A/dm2 pH 1.0 to 3.0 Bath temperature ~0 C
Others:
Boron content was controlled depending on the combination of the concentration of sodium metaborate and the pH. Plating of boron-free : - Fe was carried out without addition of sodium metaborate. :
Table 2 Type of Upper layer coatin~ (Fe-B) Sam- lower layer B content Coating Number of ple ~ __ weight (wt.%) (g/m Present invention:
l Zn 0.050 4 0 to 5 2 ~I 0.21 20 to 5 3 Zn-Ni 0.002 8 0 to 6 4 " 0.00~ 5 0 to 5 Zn-Fe 0.032 11 to 5 6 " 0.75 4 0 to 5 ~ " 2.6 3 1 to 5 _______________________ __________________________________ Comparati~e Example:
1 Zn 0 0 10 to 18 2 " 0 2 4 to 25 3 Zn-Ni O 3 5 t o 2 3 4 Zn-Fe 0 1 15 to 28 Zn-Ni 0.0004 3 2 to 22 6 Zn-Fe 0.003 0.163 to 205 . _ _ _ _ Note 1~ Comparative Examples 1 to 4 i9 provided with an upper layer comprising a boron-free Fe coating. Note Z) The coating weight in the upper layer refers to that per one side. (Ditto in Table 4, Examples 2 and 3 shown below) Note 3) The number of craterings refers to the minimum to maximum number in 10 sheets (per coating area of 5 cm x 5 cm).
Exa~ple ?
~ cold rolled steel sheet of 0.8 ~m thick was treated in the same manner as in Example 1 to make its surface clean. Thereafter, a lower layer coating comprising a Zn-Fe alloy or a Zn-Ni alloy was first provided under the conditions as shown in Table 3, and next an upper layer coating comprising al boron containing Fe-Zn alloy or a boron-free Fe-Zn alloy was provided on it.
Subsequently, samples were collected fro~ this plated steel sheet, and subjected to phosphating and electrodeposition coating in the same manner as in ~xample 1 to produce coated steel sheets having a coating film thickness of 23 um. The number of craterings generated in the coating film when provided with a boron-containing high Fe-Zn alloy coating as the upper layer is shown in Table 4.
Table 3 Conditions for lower layer coating .
Zn-Fe alloy coating _ Zn-Ni alloy coating Plating bath composition:
Ferrous sulfate 280 g/lit Nickel sulfate 260 gtlit Zinc sulfate 75 g/lit Zinc sulfate 150 g/lit Sodium sulfate ~5 g/lit Sodium sulfate 70 g/lit Plating conditions:
Current density 40 A/dm Current density 40 A/dm Bath temp. 50 C Bath temperature 55C
pH 1.6 pH 2.0 Others:
Fe content 15 to 20 wt.% Ni content 11 to 12 wt.%
Coating weight 20 g/m Coating weight 20 g~m ( er one side~ (per one side) P
Table 3 (Cont'd) Conditions for upper layer coating _ _oro containin~ hi Plating bath composition:
: Ferrous sulfate Z50 g/lit Zinc sul~ate2B ~lit Sodium sul~ate 75 g/lit Sodium ~etaborate 10 to 50 g/lit Plating conditions.
Current density 40 to ~O A/dm2 Bath temp. 50 C
p~l 1.5 to 3.0 Others:
Fe content was controlled based on the combination of the current density and the pH, and ~oron content was controlled based on the combination of the concentration of sodium metaborate and the pH.
.
Table 4 . ~
Type of Upper__ayer coatin~
__ Sa~- lower layer B con- Fe con- Coating Number o~
ple coating tent tent wei~ht (wt.%) (wt.%3 ~g/m2, Present invention: one side) 1 Zn-Ni 0.003 82 5 2 2 " 0.018 gS ~ 1 3 " 2.21 55 3 4 " 0.08 65 1 2 " O.g2 72 0.7 2 6 Zn-Fe 0.20 90 0.4 3 ~ " 1.62 85 1 0 8 " 2.61 ~3 7 0 9 " 0.05 60 1.5 0 _________ ________________________________________________ Comparative Example:
1 Zn-Ni 0 55 5 25 2 " 0 68 8 3 3 Zn-Fe 0 70 1 19 : 4 " 0 69 2 12 " 0 85 6 5 . ~ . _ _ _ (Note) Comparative Examples are provided with an upper layer comprising a boron-free Fe-Zn alloy : coating.
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Example 3 A steel strip of 0.6 mm thick and 300 mm wide was r-educed in a pre-treatment oven of a gas reduction ~yste~, and thereafter passed through a pressuri~ing chamber for preventing inflow of gas or air and a seal roll chamber in which pressure is stepwise reduced by means of a numher of seal rolls, and then introduced into a first vacuum deposition cha~ber equipped with a vacuum deposition Zn bath of an electrical resistance heating system at a lower side of the position of the steel strip, to apply a deposition coating of pure Zn on one side of the steel strip. Subsequently, the steel strip was guided to a second vacuu~ deposition chamber disposed at a lower side of the above first vacuum deposition chamber and having the same construction as the first vacuum deposition chamber to apply a deposition coating of pure 2n on the opposite side of the steel strip, and thereafter passed through a seal roll chamber and a pre~surizing cha~ber to produce a deposited steel strip having a coating weight of 50 g~ (per one side). The plating was carried out under the conditions of a steel strip moving speed of 15 ~/min a~d a vacuum degree of 0.01 Torr in both the first and second vacuum deposition chambers.
Next, part of the pure Zn-plated steel strip thus produced was introduced in an oven having an atmosphere of a mixed gas ~dew point: -25C) comprising 3 % of H2 and 97 % of N2, and heated to 280C to for~ the coating into a Zn-Fe alloy, thereby producing a steel strip provided with a coating of a Zn-Fe alloy ha~ing a~ Fe percentage of 10 wt.%.
Thereafter, this Zn-Fe alloy-plated steel strip and the pure Zn-plated steel strip were subjected to electroplating to respectively provide a Fe coating or a Fe-B coating under the same conditions as those for the upper layer coating show~ in Tahle 1, and a boron-containing high Fe-Zn coating under the same conditions as those for the upper layer coating shown in Table 3, followed by carrying out elec~rodeposition coatiny under the same conditions as in E~ample 1. The states of generation of craterings in the coating film are shown in Table 5 and Table 6.
Table 5 Type of Upper layer_coatin~ __ Sam- lower layer B content Coating Number of ple coating wei~ht craterin~s ,.
(wt.%) (g/m~, one Present invention: side) 1 Zn 0.041 3 0 to 5 2 " 0.23 2 0 to 5 3 " 0.002 9 0 to 5 4 Zn-Fe 0.003 5 1 to 5 " 0.06 4 0 to 5 6 " 2.3 2 1 to 5 Comparative Example:
: 1 Zn 0 0 tO to 20 2 " 0 2 5 to 25 3 Zn-Fe 0 4 4 to 25 4 " 0 2 15 to 30 Zn 0.0004 5 3 to 30 6 " 0.02 0.15 to S0 7 Zn-Fe 0.0003 6 5 to 30 8 " 0.005 0.14 to 47 (Note) Comparative E~amples 1 to ~ are provided with an upper layer comprising a boron-free Fe coating.
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I'able 6 .
Type of Up~ layer coating _ Sam- lower layer B con- Fe con- Coating Number of coatin~ tent tent weight_ rater n~_ (wt.%) (wt.%) (g/m , one side) Present i nvent i on:
1 2n-Ni 0.003 a 1 5 2 " ~.02 93 2 3 " 0.12 60 4 " 2.1 55 0.6 2 Zn-Fe 0.006 58 0.5 2 6 " 0.6 72 1 0 7 " 0.4 83 ~ 0 8 " 2.6 90 1.5 0 _____________________________________________ ___ ________ Comparative Example:
1 Zn 0 56 5 26 2 " 0 ~0 B 10 3 Zn-Fe 0 61 2 23 4 " 0 86 6 13 . . . _ _ _ . , , ~Note) Comparative Examples are provided with an upper layer comprising a boron-free Fe-Zn alloy coating.
Possibil-ity of industrial utilization The plated steel sheet according to -this invention can achieve a good coating appearance when used not only in automobile body components but also in other components such as electrical equipl~ent co~ponents for do~estic use and construc-tion components on which the electrodeposition coating is carried out. Since also having an excellent coating performance for coating materials other than the coating materials for the electrodeposition, the pr0sent steel sheet can be also applied in such a use for general coating.
SP~CIFICATION
excellent coating perfor~ance Technical field .
This invention relates to a plated steel shee-t excellent in the appearance of a coating ~hen applied in such a use that cationic electrodeposition coating is carried out as in the case of components for automobile bodies.
_ac~ground art In North America, Canada, North Europe and elsewhere, rock sa t is sprayed in winter to prevent roads from free~ing, and therefore steel sheets used for the co~ponents of automobile bodies are required to have excellent corrosion-resisting performance. For thi~
reason, in such a use, there have been recently applied pure zinc-plated steel sheets or zinc alloy-plated steel sheets (for example, Zn-Fe alloy-plated steel sheets, Zn-Ni alloy-plated steel sheets, and so forth) having excellent corrosion resistance.
However, there has been a problem that, in the case of a single-layer coating, these plated steel sheets may bear craterings generated on a coating film when the cationic electrodeposition coating is carried out after pho~phating, to give poor appearance of the coating.
Now, as a steel sheet that has solved the problem of the coating appearance, a double-layer plated steel sheet has been p~oposed, wherein an Fe coating that can achieve a good electrodeposition coating performance is further applied on a pure Zn or Zn alloy coating. Conventionally kno~n stee1 sheets of this type may include those wherein an upper layer comprises an Fe-Zn alloy coating having Fe content of 60 to 9o wt.~, and -those wherein an upper layer comprises an Fe coating, and it is true that the application of the cationic electrodeposition coating on these double-layer plated steel shee-ts may result in generation of a decreased number of craterings on a coating film and can improve the coating appearance.
~ owever, in order to lessen the generation of craterings on a coating film by providing the Fe-Zn alloy coating having Fe content of 60 to 90 wt.%, the coating weight must be made not less than 5 g/m2 (per one sidel, necessarily resulting in higher production cost.
Moreover, this Fe alloy coating is so hard and brittle that an infinite number of crack may be formed when a plated steel sheet is worked into a component, with the result that the lower layer i9 exposed at the cracked portion. ~herefore, when the electrodeposition coating is carried out, it ollows that the electrodeposition coating is directly applied on the lower layer, and also that craterings are liable to be generated on the coating film.
On the other hand, in the case of the Fe coating, which is softer than the Fe-Zn alloy coa-ting, no crack i5 generated even when the plated steel sheet is worked into a co~ponent, and only a little cratering is generated on the coating film. However, if the coating weight is less than 3 g/m ~per one side), there is seen variation in the quantity of the generation of craterings. Although the variation factor has not been made clear, -this i5 presumably because the covering rate in the upper layer coating relative to the lower layer coating is so poor, or the purity of the upper layer coating is so high, that large crystals of phosphate may tend to be for~ed during phosphating which is a pre-treatm~nt for the electrodeposition coating, and, as a re~ult, the rate of ~$~
covering by the phosphate crystals on the surface of a coating may be lowered and also the variation in the coveriny rate may be caused to bring about a difference in the electrolytic conduction for electrodepos.ition coating, between the phosphate deposited portion and non-deposited portion. Therefore, in order to lessen the generation of craterings on a coa~ing film by providing the Fe coating, the coatin~ wei~ht must be 3 g~m (per one side), also necessarily resulting in higher production cost.
Taking account of the fact that the electrodeposition coating performance has not been perfect even in the double-layer plated steel sheet obtained by applying the Fe coating on the pure Zn coating or Zn alloy coating as mentioned above, this invention aims at providing a plated steel sheet that has been improved the electrodeposition coating performance and yet can achieve lower production C05t.
Disclosure o This invention provides a plated steel sheet which is comprised of a plated steel sheet comprising a steel sh~et;
a lower layer coating of pure Zn or a Zn alloy, provided on the steel sheet, and an upper layer coating of an Fe-Zn alloy having an Fe percentage of 50 wt.% or more, provided on said lower layer coating, said upper layer coating containing from about O.O01 to 3 wt.~ of boron, thereby making it possible to prevent craterings being generated on a coating film and lessen the upper layer coating weight.
The reason why the plated steel sheet of this invention can have an excellent electrodeposition coating - performance i~ presumed to be that the presence of boron added to a bath at the time of the plating ~or the upper layer can improve the uniformitr of the electrodeposition to give a uniform coating, and also that the boron contained in the upper layer can serve as a nucleus at the ~, ~
. .
1 3~,~J6~ ~_! r~
time of the deposition of phosphate when a phosphating is applied as a pre-treatment for the electrodeposition coating, to form a fine and dense phosphate coating, and, as a result, the electrolytic conduction on the entire surface of a steel sheet becomes uniform, whereby a coating material can be uniformly electrodeposited at the time the electrodepositior~ coating is carried out, and thus the generation of craterings can be stably restrained.
Best mode for workin~ the invention The plated steel sheet of this invention can restrain the generation of craterings in a coating film even when the coating weight is not more than 3 g/m2 per one side in the case the upper layer comprises the boron-containing Fe coating, or even when the coating weight is not more than 5 g/m2 per one side in the case the upper layer comprises the above element-cor.taining Fe alloy coating, This is presumably because, even if the coating weight is small, the upper layer can cover the lower layer so excellently that the rate of covering of the lower layer by the upper layer can be improved.
In the case the upper layer comprises the Fe-Zn alloy coatlng, it has been conventionally i~possible to lessen the generation of craterings in a coating film unless Fe content is controlled to less than 60 to 100 wt.%. However, the presence of boron contained makes it possible to lessen the generation of craterings in a coating film even if the Fe content is decreased to 50 to 100 wt.%. This is presumably because of the above mentioned effect of improving the phosphating performance, and once the Fe content can be decreased like this, the difference in the corrosion potential between the upper layer and the lower layer becomes smalll whereby the corrosion resistance of the coa-tings as a whole for a long period can be improved.
The amount of boron contained in the upper layer may preferably be controlled to 0.001 to 3 wt.%. This is because the boron amount of less -than 0.001 wt.~ may result in no difference ~rom an upper layer containing no boron in respect of the generation of craterings and variation thereof in the electrodeposition coating, and the boron amount more than 3 wt.% may result in saturation of the effect so that it is meaningless to make the amount larger than that.
The covering weight on the upper layer (per one side) may be preferably controlled to 0.5 to 10 gtm2 in the case of the boron-containing Fe coating, and 0.2 to ~
g/m2 in the case of the Fe alloy coating. This is because the weight of less than 0.5 g/m2 or 0.2 g/m2 may make it impossible to achieve perfect covering of the lower layer to bring about the generation of craterings in a coating film to be caused by the exposure of the lower layer at the time of the electrodeposition coating, and the weight more than 10 g/m2 or 3 g/m2 may result in saturation of the ef~ect of restraining the generation of craterin~s in a coating film so that it is unnecessary to make the coating weight larger than that. Meanwhile, in the case of the conventional upper layer coating comprising the Fe-Zn alloy containing no boron, the effect of restraining the generation of craterings in a coating film has been saturated when the weight is 10 g 10/m2 g. The effect by virtue of the addition of boron can be seen also in this - point, in respect of the decrease in the coating weight.
In order to codeposit boron into the upper layer in an amount of 0.001 to 3 wt.% according to electroplating, th~ plat.ing may be carried out by adding one or more of boron compound(s) such as boric acid, metaboric acid, water soluble metaborate, water soluble tetraborate and tetrafluorsborate to an ordinary Fe plating bath or a plating bath of an Fe alloy such as an Fe-Zn alloy and an , ~., ~
~3~
~;
Fe-Ni alloy, and adjusting the pH of the bath to 1 to 3.
The steel sheet according to this in~ention can improve the performance in the electrocleposition coating of a pure Zn-plated or Zn alloy-plated steel sheet.
However, in the case the lower layer comprises an Zn alloy coating of a Zn-Ni or Zn-Fe alloy, the generation of craterings can be restrained even with imclusion of a trace amount of o~e or more of elements su~h as Ni ~in respect of the Zn-Fe alloy), Fe ~in respect of the Zn-Ni alloy), Co, Cr, Mn, Mo and Ti. In the case the lower layer comprises a pure Zn coating, it can be also restrained even with respect to coatings obtained by carrying out electroplating, vacuum deposition or hot dipping. Further, in the case the upper layer comprises the Zn alloy coating, it can be also restrained even with respect, in addition to the coatings formed by the above methods, to those which are alloyed into a Zn-Fe alloy by thermal diffusion after carrying out hot dip ~inc coating or vacuum zinc deposition as in the case of an alloyed zinc-plated steel sheet.
This invention will be described below more specifically by ~xamples.
Example 1 On a cold rolled steel sheet of 0.8 mm thick, usual treatments of degreasing and acid pickling were applied to make its surface clean. Therea~ter, a lower layer coating comprising pure Zn, an Zn-Fe alloy or Zn-Ni alloy was first provided according to electroplating under the conditions as shown in Table 1, and next an upper layer coating comprising Fe or Fe-B was provided on it according to the same plating method.
Subsequently, from the thus plated steel sheet, samples were collected by 10 sheets per each plating condition, which were treated with a commercially available phbsphating solution (Bondelite #3030*; produced by Nippon Parker Co.), followed by carrying out cationic *Trade mark . , ' ' , electrodeposition coating to examine the number of craterings generated on the coatings after drying by baking. In the electrodeposition, ~lcon* #9000 (produced by Kansai Paint Co., Ltd.) was used as a coating material, which was electrodeposited according to an instantaneous voltage-increasing ~ethod (the so-called "dokan" method) under 300 V to have a coating film thickness of 25 um, and the baking was carried out at 1~0C for 20 minutes. The number of craterings generated in the coating film when provided with an Fe-B coating as the upper layer is shown in Table 2.
As will be clear ~rom Table 2, the steel sheets of this invention, provided with an Fe-B coating as the upper layer, show less generation o~ craterings and variation thereof than those in conventional double-layer plated steel sheets provided with an upper layer Zn coating and having a good electrodepo~ition coating perfor~ance, even with a lower layer comprising a pure Zn coating or a Zn alloy coating.
*Trade mark ~ J~P~ ~
Table 1 Conditions for lower layer coating _ _ ... .
Pure Zn coating Zn-Fe alloy coating Plating bath composition:
Zinc sulfate 240 g/lit Ferrous sulfate ,'80 g/lit Sodium sulfate 75 g/lit Zinc sulfate 75 g/lit Sodium sulfate 85 g/lit Plating conditions:
pH 1.5 pH 1.6 Bath temperature 50C Bath temperature 50C
Current density 20 A/dm2 Current density 40 A/dm Others:
Fe content 15 to 20 wt.%
- Coating weight 20 g/m2 _ (~E~r one side) Conditions for lower layer coating (Cont'd) Zn-Ni alloy coating Plating bath composition:
Nickel sulfate 260 g/lit Zinc sulfate 150 g/lit Sodium sulfate 70 g/lit Plating conditions:
pH 2.0 Bath temperature 55C
Current densit-y 40 A/dm Others:
Ni content 11 to 12 wt.%
Coating weight 20 g/m2 (~er one side) . ~ .. . .
~3~
Table 1 (cont'd) Condit.ions for upper layer coating _ Fe-B coating _ Plating bath composition:
Ferrous sulfate 250 g/lit Sodium sulfate 70 g/lit Tartaric acid 3 g/lit Sodium metaborate 10 to 50 g/lit Plating conditions:
Current density 20 to 30 A/dm2 pH 1.0 to 3.0 Bath temperature ~0 C
Others:
Boron content was controlled depending on the combination of the concentration of sodium metaborate and the pH. Plating of boron-free : - Fe was carried out without addition of sodium metaborate. :
Table 2 Type of Upper layer coatin~ (Fe-B) Sam- lower layer B content Coating Number of ple ~ __ weight (wt.%) (g/m Present invention:
l Zn 0.050 4 0 to 5 2 ~I 0.21 20 to 5 3 Zn-Ni 0.002 8 0 to 6 4 " 0.00~ 5 0 to 5 Zn-Fe 0.032 11 to 5 6 " 0.75 4 0 to 5 ~ " 2.6 3 1 to 5 _______________________ __________________________________ Comparati~e Example:
1 Zn 0 0 10 to 18 2 " 0 2 4 to 25 3 Zn-Ni O 3 5 t o 2 3 4 Zn-Fe 0 1 15 to 28 Zn-Ni 0.0004 3 2 to 22 6 Zn-Fe 0.003 0.163 to 205 . _ _ _ _ Note 1~ Comparative Examples 1 to 4 i9 provided with an upper layer comprising a boron-free Fe coating. Note Z) The coating weight in the upper layer refers to that per one side. (Ditto in Table 4, Examples 2 and 3 shown below) Note 3) The number of craterings refers to the minimum to maximum number in 10 sheets (per coating area of 5 cm x 5 cm).
Exa~ple ?
~ cold rolled steel sheet of 0.8 ~m thick was treated in the same manner as in Example 1 to make its surface clean. Thereafter, a lower layer coating comprising a Zn-Fe alloy or a Zn-Ni alloy was first provided under the conditions as shown in Table 3, and next an upper layer coating comprising al boron containing Fe-Zn alloy or a boron-free Fe-Zn alloy was provided on it.
Subsequently, samples were collected fro~ this plated steel sheet, and subjected to phosphating and electrodeposition coating in the same manner as in ~xample 1 to produce coated steel sheets having a coating film thickness of 23 um. The number of craterings generated in the coating film when provided with a boron-containing high Fe-Zn alloy coating as the upper layer is shown in Table 4.
Table 3 Conditions for lower layer coating .
Zn-Fe alloy coating _ Zn-Ni alloy coating Plating bath composition:
Ferrous sulfate 280 g/lit Nickel sulfate 260 gtlit Zinc sulfate 75 g/lit Zinc sulfate 150 g/lit Sodium sulfate ~5 g/lit Sodium sulfate 70 g/lit Plating conditions:
Current density 40 A/dm Current density 40 A/dm Bath temp. 50 C Bath temperature 55C
pH 1.6 pH 2.0 Others:
Fe content 15 to 20 wt.% Ni content 11 to 12 wt.%
Coating weight 20 g/m Coating weight 20 g~m ( er one side~ (per one side) P
Table 3 (Cont'd) Conditions for upper layer coating _ _oro containin~ hi Plating bath composition:
: Ferrous sulfate Z50 g/lit Zinc sul~ate2B ~lit Sodium sul~ate 75 g/lit Sodium ~etaborate 10 to 50 g/lit Plating conditions.
Current density 40 to ~O A/dm2 Bath temp. 50 C
p~l 1.5 to 3.0 Others:
Fe content was controlled based on the combination of the current density and the pH, and ~oron content was controlled based on the combination of the concentration of sodium metaborate and the pH.
.
Table 4 . ~
Type of Upper__ayer coatin~
__ Sa~- lower layer B con- Fe con- Coating Number o~
ple coating tent tent wei~ht (wt.%) (wt.%3 ~g/m2, Present invention: one side) 1 Zn-Ni 0.003 82 5 2 2 " 0.018 gS ~ 1 3 " 2.21 55 3 4 " 0.08 65 1 2 " O.g2 72 0.7 2 6 Zn-Fe 0.20 90 0.4 3 ~ " 1.62 85 1 0 8 " 2.61 ~3 7 0 9 " 0.05 60 1.5 0 _________ ________________________________________________ Comparative Example:
1 Zn-Ni 0 55 5 25 2 " 0 68 8 3 3 Zn-Fe 0 70 1 19 : 4 " 0 69 2 12 " 0 85 6 5 . ~ . _ _ _ (Note) Comparative Examples are provided with an upper layer comprising a boron-free Fe-Zn alloy : coating.
~3U~
Example 3 A steel strip of 0.6 mm thick and 300 mm wide was r-educed in a pre-treatment oven of a gas reduction ~yste~, and thereafter passed through a pressuri~ing chamber for preventing inflow of gas or air and a seal roll chamber in which pressure is stepwise reduced by means of a numher of seal rolls, and then introduced into a first vacuum deposition cha~ber equipped with a vacuum deposition Zn bath of an electrical resistance heating system at a lower side of the position of the steel strip, to apply a deposition coating of pure Zn on one side of the steel strip. Subsequently, the steel strip was guided to a second vacuu~ deposition chamber disposed at a lower side of the above first vacuum deposition chamber and having the same construction as the first vacuum deposition chamber to apply a deposition coating of pure 2n on the opposite side of the steel strip, and thereafter passed through a seal roll chamber and a pre~surizing cha~ber to produce a deposited steel strip having a coating weight of 50 g~ (per one side). The plating was carried out under the conditions of a steel strip moving speed of 15 ~/min a~d a vacuum degree of 0.01 Torr in both the first and second vacuum deposition chambers.
Next, part of the pure Zn-plated steel strip thus produced was introduced in an oven having an atmosphere of a mixed gas ~dew point: -25C) comprising 3 % of H2 and 97 % of N2, and heated to 280C to for~ the coating into a Zn-Fe alloy, thereby producing a steel strip provided with a coating of a Zn-Fe alloy ha~ing a~ Fe percentage of 10 wt.%.
Thereafter, this Zn-Fe alloy-plated steel strip and the pure Zn-plated steel strip were subjected to electroplating to respectively provide a Fe coating or a Fe-B coating under the same conditions as those for the upper layer coating show~ in Tahle 1, and a boron-containing high Fe-Zn coating under the same conditions as those for the upper layer coating shown in Table 3, followed by carrying out elec~rodeposition coatiny under the same conditions as in E~ample 1. The states of generation of craterings in the coating film are shown in Table 5 and Table 6.
Table 5 Type of Upper layer_coatin~ __ Sam- lower layer B content Coating Number of ple coating wei~ht craterin~s ,.
(wt.%) (g/m~, one Present invention: side) 1 Zn 0.041 3 0 to 5 2 " 0.23 2 0 to 5 3 " 0.002 9 0 to 5 4 Zn-Fe 0.003 5 1 to 5 " 0.06 4 0 to 5 6 " 2.3 2 1 to 5 Comparative Example:
: 1 Zn 0 0 tO to 20 2 " 0 2 5 to 25 3 Zn-Fe 0 4 4 to 25 4 " 0 2 15 to 30 Zn 0.0004 5 3 to 30 6 " 0.02 0.15 to S0 7 Zn-Fe 0.0003 6 5 to 30 8 " 0.005 0.14 to 47 (Note) Comparative E~amples 1 to ~ are provided with an upper layer comprising a boron-free Fe coating.
~3~
I'able 6 .
Type of Up~ layer coating _ Sam- lower layer B con- Fe con- Coating Number of coatin~ tent tent weight_ rater n~_ (wt.%) (wt.%) (g/m , one side) Present i nvent i on:
1 2n-Ni 0.003 a 1 5 2 " ~.02 93 2 3 " 0.12 60 4 " 2.1 55 0.6 2 Zn-Fe 0.006 58 0.5 2 6 " 0.6 72 1 0 7 " 0.4 83 ~ 0 8 " 2.6 90 1.5 0 _____________________________________________ ___ ________ Comparative Example:
1 Zn 0 56 5 26 2 " 0 ~0 B 10 3 Zn-Fe 0 61 2 23 4 " 0 86 6 13 . . . _ _ _ . , , ~Note) Comparative Examples are provided with an upper layer comprising a boron-free Fe-Zn alloy coating.
Possibil-ity of industrial utilization The plated steel sheet according to -this invention can achieve a good coating appearance when used not only in automobile body components but also in other components such as electrical equipl~ent co~ponents for do~estic use and construc-tion components on which the electrodeposition coating is carried out. Since also having an excellent coating performance for coating materials other than the coating materials for the electrodeposition, the pr0sent steel sheet can be also applied in such a use for general coating.
Claims (12)
1. A plated steel sheet having an excellent coating performance, comprising a steel sheet; a lower layer coating of pure Zn or a Zn alloy, provided on the steel sheet; and an upper layer coating of an Fe-Zn alloy having an Fe percentage of 50 wt.% or more, provided on said lower layer coating, said upper layer coating containing from about 0.001 to 3 wt.% of boron.
A plated sheet according to claim 1, wherein the upper layer coating has a coating weight of from about 0.2 to 8 g/m2.
3. A plated steel sheet having an excellent coating performance, comprising a steel sheet; a lower layer coating of pure Zn or a Zn alloy, provided on the steel sheet; and an upper layer coating of Fe provided on said lower layer coating, said upper layer coating containing from about 0.001 to 3 wt.% of boron.
4. A plated sheet according to claim 3, wherein the upper layer coating has a coating weight of from about 0.5 to 10 g/m2.
5. A plated sheet according to claim 1, wherein said Zn alloy comprises a Zn-Ni or a Zn-Fe alloy.
6. A plated sheet according to claim 5, wherein said alloy further comprises a trace amount of one or more additional elements selected from Ni, Fe, Co, Cr, Mn, Mo and Ti.
7. A plated sheet according to claim 3, wherein said Zn alloy comprises a Zn-Ni or a Zn-Fe alloy.
8. A plated sheet according to claim 7, wherein said alloy further comprises a trace amount of one or more additional elements selected from Ni, Fe, Co, Cr, Mn, Mo and Ti.
9. A plated sheet according to claim 1, wherein said upper layer coating has been applied by electrodeposition in the presence of at least one boron compound.
10. A plated sheet according to claim 9, wherein said boron compound comprises boric acid, metaboric acid, a water soluble metaborate, a water soluble tetraborate or a tetrafluoroborate.
11. A plated sheet according to claim 3, wherein said upper layer coating has been applied by electrodeposition in the presence of a least one boron compound.
12. A plated sheet according to claim 11, wherein said boron compound comprises boric acid, metaboric acid, a water soluble metaborate, a water soluble tetraborate or a tetrafluoroborate.
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61071884A JPS62228498A (en) | 1986-03-29 | 1986-03-29 | Plated steel sheet for painting |
| AU72080/87A AU589767B2 (en) | 1986-03-29 | 1987-03-27 | Plated steel sheet |
| KR1019870700831A KR920009844B1 (en) | 1986-03-29 | 1987-03-27 | Plated steel sheet having excellent coating performance |
| PCT/JP1987/000190 WO1987005950A1 (en) | 1986-03-29 | 1987-03-27 | Plated steel excellent in coatability |
| EP87902156A EP0264455B1 (en) | 1986-03-29 | 1987-03-27 | Plated steel excellent in coatability |
| DE87902156T DE3786056T2 (en) | 1986-03-29 | 1987-03-27 | COATED STEEL WITH EXCELLENT COATABILITY. |
| CA000539351A CA1309055C (en) | 1986-03-29 | 1987-06-10 | Plated steel sheet having excellent coating performance |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61071884A JPS62228498A (en) | 1986-03-29 | 1986-03-29 | Plated steel sheet for painting |
| CA000539351A CA1309055C (en) | 1986-03-29 | 1987-06-10 | Plated steel sheet having excellent coating performance |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1309055C true CA1309055C (en) | 1992-10-20 |
Family
ID=25671379
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000539351A Expired - Lifetime CA1309055C (en) | 1986-03-29 | 1987-06-10 | Plated steel sheet having excellent coating performance |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0264455B1 (en) |
| JP (1) | JPS62228498A (en) |
| KR (1) | KR920009844B1 (en) |
| AU (1) | AU589767B2 (en) |
| CA (1) | CA1309055C (en) |
| DE (1) | DE3786056T2 (en) |
| WO (1) | WO1987005950A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0610358B2 (en) * | 1986-12-06 | 1994-02-09 | 日新製鋼株式会社 | Multi-layer electric plated steel sheet |
| EP0285931B1 (en) * | 1987-03-31 | 1993-08-04 | Nippon Steel Corporation | Corrosion resistant plated steel strip and method for producing same |
| JPS6428351A (en) * | 1987-07-23 | 1989-01-30 | Nisshin Steel Co Ltd | Method for hot dip aluminizing hardly aluminizable steel sheet |
| KR910003036B1 (en) * | 1988-12-30 | 1991-05-17 | 포항종합제철 주식회사 | Corrosion excellant resistance fe-mn coating steel sheets and process for making |
| AT400040B (en) * | 1993-06-02 | 1995-09-25 | Andritz Patentverwaltung | METHOD AND DEVICE FOR COATING METAL SUBSTRATES, IN PARTICULAR STEEL OR ALUMINUM SHEETS IN STRIP SHAPE |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56142885A (en) * | 1980-04-08 | 1981-11-07 | Nippon Steel Corp | Steel material with plural plating layers |
| JPS59116393A (en) * | 1982-12-23 | 1984-07-05 | Kobe Steel Ltd | Surface-treated steel sheet with superior corrosion resistance after coating |
-
1986
- 1986-03-29 JP JP61071884A patent/JPS62228498A/en active Granted
-
1987
- 1987-03-27 AU AU72080/87A patent/AU589767B2/en not_active Ceased
- 1987-03-27 DE DE87902156T patent/DE3786056T2/en not_active Expired - Fee Related
- 1987-03-27 EP EP87902156A patent/EP0264455B1/en not_active Expired - Lifetime
- 1987-03-27 WO PCT/JP1987/000190 patent/WO1987005950A1/en active IP Right Grant
- 1987-03-27 KR KR1019870700831A patent/KR920009844B1/en not_active IP Right Cessation
- 1987-06-10 CA CA000539351A patent/CA1309055C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| AU589767B2 (en) | 1989-10-19 |
| EP0264455B1 (en) | 1993-06-02 |
| DE3786056T2 (en) | 1993-10-28 |
| WO1987005950A1 (en) | 1987-10-08 |
| KR920009844B1 (en) | 1992-10-31 |
| JPH0156159B2 (en) | 1989-11-29 |
| JPS62228498A (en) | 1987-10-07 |
| EP0264455A1 (en) | 1988-04-27 |
| AU7208087A (en) | 1987-10-20 |
| DE3786056D1 (en) | 1993-07-08 |
| KR880700868A (en) | 1988-04-13 |
| EP0264455A4 (en) | 1991-03-13 |
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