JPS5923872A - Production of ordinary steel baked with glass enamel - Google Patents

Abstract

PURPOSE:To obtain easily a glass enamel baked film adhered securely to an ordinary steel without foaming, by applying electric chrome plating on the steel prior to application of glass enamel. CONSTITUTION:Electric chrome plating is applied on an ordinary steel contg. >=0.03% carbon, then glass enamel is applied thereon. The glass enamel having various colors can thus be applied on the surface of the ordinary steel plate by direct application. The enamel is baked after the application. Numerous fine cracks are generated on the plating layer in the stage of the baking, and the molten glass enamel enter the inside of the cracks; at the same time, a proper amt. of the steel melts from the blank material through the cracks into the enamel, whereby the adhesiveness is presumably improved additionally. The plating layer prevents the excessive oxidation in the stage of the baking and suppresses the attack of the moisture ad oxygen in the glass enamel thereby suppressing presumably the reaction of the moisture and oxygen with the carbon in the blank material.

Description

[Detailed Description of the Invention] The present invention relates to a method for producing glass enamel baked common steel,
The purpose of this is that glass enamel in various colors can be glazed directly onto the surface of ordinary steel, making it easy and economical to use ordinary steel with a 1-mel baked coating that does not bubble and is firmly bonded. It offers a new method of manufacturing.

Conventionally, there is a so-called direct method of coating the surface of the metal material with enamel by baking a glass-like enamel onto the surface of the metal material such as mild steel (carbon content less than 0.603%) or copper plastic. It is well known as hanging enamel processing. However, when the above-mentioned direct coating method is applied to ordinary steel, such as ordinary carbon steel or cast iron, which has a carbon content of 0.03% or more, the carbon contained in the ordinary steel may be absorbed by water or oxygen in the glaze. During firing, the enamel reacted with the enamel to generate gas, which caused bubbles to form on the surface of the glazed enamel, making it impossible to obtain a smooth, strong enamel with excellent adhesion.

Therefore, conventionally, the method of direct lamination has mainly been applied to special decarbonized steel sheets called ultra-low carbon steel sheets (with a carbon content of 0.003
%F) is used as a material, and it is pretreated by pickling etc.
Then, after applying a two-shelf treatment, apply a glaze, or
Alternatively, steel materials have been used in which elements such as titanium and niobium, which have a strong affinity for carbon, are impregnated in advance. However, the above-mentioned materials are hardly advantageous in terms of their manufacturing process and economy.

The present invention provides a new and useful technique that allows glass enamel to be baked onto D-sequences, which is difficult to produce with conventional direct enameling, and to form a strongly bonded enamel cover without bubbles. It is something to do.

That is, the present invention is a direct-hanging method which is characterized in that common steel with a carbon content of 0.03% or more is electroplated with ROM and then 25 laths enameled.
Pertains to the manufacturing method of mel-baked ordinary steel.

According to the method of the present invention, it is possible to form a fired film by directly applying the fris enameling to common steel in a highly efficient manner. Moreover, the resulting glass enamel baked coating has no bubbles on its surface and is extremely smooth, and the coating has been subjected to an impact test (for example, in which a 200V steel ball is dropped from a height of 1 m (I) onto the coating). JISR4301) C also peel off f, 1
Ta500'CK It has a very strong adhesive strength with no abnormality observed even after repeating the cycle of holding it for 1 hour and then rapidly cooling it in gold water 5 times. The reason why the method of the present invention forms a glass enamel baked coating with the above-mentioned adhesive property [1] is not clear, but generally speaking, when ordinary steel is coated with the glass enamel, the adhesion is extremely poor and Scale (oxide film) generated from the filling material
Also, the glass enamel may fall off during cooling after baking,
In view of the appearance of bubbles on the surface, according to the present invention, by forming a chromium plating layer on the surface of ordinary steel in advance, numerous cracks are generated on the plating layer when glass enamel is baked, and this The glass enamel in a molten state enters into the crack, improving adhesiveness through mechanical interlocking, and at the same time, an appropriate amount of iron is released from the material through the crack.
1 Dissolved in lath enamel, step by step Fe (base) -0
-Fe -0-5i ()5 Oxygen bonds in the lath enamel 9 are formed, which is thought to further improve adhesiveness. The ROM plating layer on the top of the housing prevents excessive acid fiz on the base material during firing, and also suppresses the attack of moisture and oxygen in the glass enamel, making it difficult for reactions between these and the carbon in the material. It is considered that The fact that numerous cracks occur in the chromium plating layer in the method of the present invention can be confirmed by observing the surface condition and yoke of the plating layer with a metallurgical microscope after firing the chromium-plated material under glass enamel firing conditions. In any case, the present invention makes it possible to form a baked glass enamel film by directly applying it to ordinary steel, which was previously considered impossible, based on the fact that glaze is applied after the formation of the above-mentioned 0mm plating layer. Furthermore, the coating does not foam and is firmly adhered to the material, making it extremely useful in practice.

The ordinary steel to which the method of the present invention is applied has a carbon content of 0.
．． There is no particular restriction as long as the content is 0.3% or more, and ordinary carbon steel, cast iron, etc. can be used.

In the present invention, it is essential that the above-mentioned common steel is first pretreated and then subjected to gaseous chromium plating according to a conventional method. The above pretreatment includes a degreasing step and a pickling step that are commonly used in the plating field. Examples of the degreasing agent used in the degreasing step include common ones such as hydric soda, soda carbonate, sodium silicate, tribasic sodium phosphate, and surfactants. In addition, in the pickling process, mixed acids such as ordinary sulfuric acid, hydrochloric acid, etc. are used to remove scale and dirt on the surface of the material and activate the surface. In order to roughen the surface of the material, sandblasting, emery paper, etc. can be used to perform a plus 1 treatment, and this plast treatment can also be applied to the plating film after chrome plating, so that it will not continue to be formed. The adhesion of the glass enamel baked coating can be made even stronger.

In addition, the electrochromium plating of the present invention uses ordinary chromic acid-4
Chromium plating can be carried out according to a conventional method using a tL acid bath (a J-dient bath, a chromic acid=fluoride bath, etc. as described above).
005'/l, sulfuric acid (ll2So4) l -4! /I
(com C) and trivalent (com C)
Cr) U-5-, 1/l, more preferably chromic acid 2
509/(1, sulfuric acid 2.51/l and trivalent Dum 1-2
Using a 1y-diecite bath having a composition of 9/l, the bath temperature is about 40-50'C, the current density is 15-20Aldd, and the plating time is about 30 seconds-30 minutes, preferably about 1-5 minutes. will be implemented. The plating film thickness is determined according to the above-mentioned plating time, and is usually about Q, 1-3 μm, preferably about 0.25-1 py17. The thickness of this plating film affects the characteristics of the enamel baked film formed by subsequent application of glass enamel, especially the adhesion to the raw metal and the smoothness of the surface of the film. When the plating rpX thickness is within the range mentioned above, it is possible to form a glass enamel baking rupture film that is excellent in smoothness as expected in this study, has no bubbling, and has very strong adhesion, whereas the above-mentioned plating film If the thickness is too thin than 0.1 μm, the material metal will not be sufficiently covered by the plating film,
If the degree of exposure becomes too large, this exposed part will receive excessive oxidation during firing of the glass enamel, causing scale formation, and there is a risk of reducing the contact property of the fired glass enamel film with the material metal. At the same time, the exposed portions are attacked by moisture or oxygen in the glass enamel, and scum is generated due to reaction with carbon in the raw metal, causing bubbling, which may impair the smoothness of the enamel coating surface. In addition, if the 1M thickness of the plating is too thick than 3 μm, there is no risk of the above-mentioned problems occurring, but when glazing enamel on the plating layer and firing it, the number of cracks that occur in the plating layer under the firing conditions. This decreases the physical entanglement between the plating layer and the glass enamel coating, which may reduce the adhesion. However, this low F adhesiveness can be solved by, for example, performing sufficient acid treatment or mechanical roughening in the pre-treatment process of the electrochromium plating, or by applying a conventional method to the plating film after the plating process. This can be sufficiently prevented by roughening the surface by performing /Jll machining or the like. Therefore, in the present invention, on the premise that the above-mentioned pre-treatment or post-treatment is carried out, for example, the so-called tart-free plating or micro-crack plating, which employs the bath composition and plating conditions as described below, is carried out as the above-mentioned electroplating. It is also possible to adopt a plating method such as the following.

Crack-free plating 2 Bath composition cr O3300-4009/ (1if
2soL, 2-3f/(1 cr" o, 3-o, 8yil Bath temperature 47-55'c Current density 30-35 A/dtd plating time
1-3 minutes micro cracking 2? Bath composition c, O3180-2209/(j
It2SO41-1,71171 1"J2SiF5'J-,5-5y/(1 bath temperature
45-50'C゛6 days Current density 1O-2OA/d Horn J plating time 5-10 minutes In the present invention, after the above electrochromium plating, it is washed with water and dried, and if necessary, the surface of the plating film is further roughened. After that, glass enamel is applied. 5. Roughening of the surface of the plating film described above is not particularly necessary, but if the plating film is relatively thick, it may be formed by crack-free plating or micro-crack plating. This method is effective in the case where the glass enamel baked coating is firmly bonded with the glass enamel coating desired by the present invention. For example, a puff method using emery paper or a talust method using a run 1 unit can be adopted.

In addition, the oiling of Nocolas enamel can be done by the same method as the direct enameling process conventionally used for ultra-low carbon steel sheets, copper, aluminum, etc.) 3 lath enamel itself , Various known products such as commercially available enamel overglaze, enamel paint, 7j
Karasu color used for lath decoration, 5 lath enamel for Sdeyless steel decoration, etc. may be used. The glass constituting the above-mentioned glass enamel is preferably 51o2-H
2O3-R20 series or 5i02- H2O3-PbO-
In order to impart chemical resistance to R20 series (R2 represents an alkali metal such as Na, K, or Lr4) Nocolas or these, lro2, rr02, Al2O3,
5b203, etc., a mixture of at least one of the above Sr. 02-/J2C)
All examples include 3-pbo-R20 glass containing CdO in order to stabilize the color development of red (glass enamel using dotrium pigments).

Another preferred glass enamel is titanium enamel, which has a relatively large amount (approximately 2
Contain around 0% Ca or to increase emulsion.
O, Z/Ic), MyO, etc., or P to stabilize the anatapi crystal of titanium y.
2O5 etc. can be added.

Further, as the shield agent to be blended into the above-mentioned Nocolas enamel, a wide range of ordinary heat-resistant inorganic pigments and heat-resistant colored metal oxides can be used. Typical examples thereof include titanium trioxide, cadmium yellow, chromium oxide, and cobalt oxide.

More preferably, as a method for applying the glaze to the various Noras Eymel, for example, 100 parts by weight of the above Sue J-Mel is added with a suitable organic glaze according to a conventional method, such as 1 manufactured by Jitsukei Pharmaceutical Industries Co., Ltd.
-S↑-Dioil Hand 9028), etc., are mixed and kneaded, and the paste thus obtained is screen printed, or the paste is further mixed with an appropriate organic solvent such as ethanol, etc. Dilute (paste 1oofi
The diluted solution obtained by using approximately 30 double feeding parts of an organic solvent for each part of Jt is sprayed using the usual method e, followed by the spray method, Diji: J
') Methods of construction can be mentioned. Further, the above glazing is a transfer process in which the paste or diluted solution prepared as described above is applied to a suitable transfer base material, and this is transferred to a suitable steel surface coated with electrochrome plating of the present invention according to a conventional method. The application of glass enamel by the above-mentioned methods is not particularly limited, and can be arbitrarily determined depending on the desired color tone, pattern, etc. of the baked coating, but is usually tJ20-40μ? Generally, it is about n.

After the above-mentioned glazing, according to the present invention, the dried film is baked in accordance with the usual method at a temperature higher than the softening point of the 7J lath enamel, usually about 600-800''C, for about 3-10 minutes. It is possible to obtain ordinary steel products on which a glass enamel baked coating is formed as intended by the invention.

The thus obtained product of the present invention can also be finished with a baked coating according to a conventional method. In other words, in the case of a partially decorated product obtained by applying glass enamel to any part of the base material in a design, pattern, etc., the non-decorated part generally loses its aesthetic appearance. The parts are finished with various types of plating to give them a beautiful appearance. As the finishing method, for example, a product that has been partially baked with glass enamel tea according to the method of the present invention is first subjected to anodic electrolysis for about 1 minute at room temperature in a 000% acid bath (about 1009%/l of 000% solution/l). Then, remove the chromium plating layer that is not covered with the glass enamel coating, wash with water, activate with acid such as Top Acid 1509/β (manufactured by Jitsukei Pharmaceutical Industry Co., Ltd.) at room temperature F for about 30 seconds, and wash again with water. , In addition to this, sulfuric acid steel plating, semi-bright nickel plating, bright nickel plating,
Further, chrome plating or the like may be performed. The plating baths and plating conditions used in this finishing process are not different from those of ordinary methods, and one particularly preferred example is as follows.

Copper sulfate plating 2 Bath composition Sulfuric acid @ 220t #sulfuric acid
30txl/l [Caparaside MV] 5 scraps 1/it 1 Caparaside 210AJ O, 5 Shoulder t/1 Note that the above 1-Caparaside MVJ and [Caparaside 210AJ are both brightening agents manufactured by Jitsukei Pharmaceutical Industry Co., Ltd. 'C Flow density 3 A/d Plating time 30 minutes〈Semi-bright nickel plating 2 Bath composition Nickel sulfate 2B0f/1 Nickel chloride 45971 Boric acid 40 f/l UAcna SGL-AIVJ 1.5-3 xl/1
"Aqua SGL-MVJ is a brightener manufactured by Jitsukei Pharmaceutical Industries.

Bath temperature 50°C Current density 3A/did Plating time 20 minutes Bright nickel plating Bath composition Nickel sulfate 280 &//Nickel chloride 459/II Boric acid 40f/1 1 Acuna B-IJ 20w1/(1 [Aqua B
-2J L Shoulder T/41-Aqua B-1' and [Akuf H-24] are brightener baths manufactured by Jitsukei Pharmaceutical Industry Co., Ltd. Temperature: 50°C Current density: 3 A/dtd Plating time: 10 minutes 0 Mumeriki> Bath composition Rimu acid )! , 50f/1 sulfuric acid 2
．． 51/1 Trivalent Dum 29/1 Bath temperature 50'C 1 Flow density 20 A/d Gold plating time 2 minutes or more F Examples will be given to explain the present invention in more detail.

Example l Ordinary steel plate (/
I'S G-3141) spct ) t
50f//l), immersed at 70'C for 15 minutes to degrease,
After washing with water, use an acid activator (Jitsumei Yaku Kogyo Co., Ltd., “Tonic Acid J70”)
11/(J), activate the chamber @F for 30 seconds, wash with water, and then soak in a diethite bath (Cry3250 f/l, 112So
42.5 Q/l and Cr 21171) Electrical D-plating was carried out at a C1 bath temperature of 45 C and a current density of 15-20 A/dyf for a predetermined time (approximately 1-25 minutes), and after washing with water and drying, the above plating time 1... Approximately QJ pm-3μ depending on
Each test plate with a plating thickness of m was obtained.

'i = 700'C-r 1 of each sample plate obtained
The oxidized weight changes were determined by firing for a certain period of time.

In addition, each of the above test plates was separately glazed with "Black Paste for Stainless Steel UP: L-42J" manufactured by Jitsukei Pharmaceutical Industries Co., Ltd., having the composition shown in F, by screen printing with a size of 40 x 7 C) fl using a 180 mesh screen.

Kuste:, II7 black paste MEL-42 composition 2 "X02-";zo, 5-R2o system n 5 Sufu')
) 90tRJk section 5i (),
55.0, i! lit%BO20-Or3 1VaO'7.0 #Li () 4.0
#20 Q, 5 wt% NaF
1,5 zAI! (J
5-0 13 zro27.0 #Face-heating inorganic pigment] 10 parts by weight of Balt-Zu Riff Next, after thoroughly drying the above-mentioned glazed test plate, 72
The product was baked at 0'C for 3 minutes and cooled in air to obtain the product of the present invention.

The presence or absence of foaming on the enamel surface of each of the obtained products and the adhesion (rain shock resistance and heat shock resistance) were tested according to section f.

<Adhesion test 2 1-@Impact property iIs According to R4301, a steel ball (200f) with a diameter of 36.51ffl specified in JIS B1501 was dropped from a height of 1 m onto the glass enamel baked surface, and the peeling state of the impact surface was determined as follows. Judgment was made according to the criteria.

A: No peeling at all 8: Peeling only at the impact part C: Peeling spread from the #-shaped part D: Peeling already observed during cooling 2, Heat shock resistance s After holding each product (glass enamel baked plate) at o o 'c for 1 hour, it was placed in cold water, and the peeling status at that time was judged according to the following criteria.

A: No peeling at all B: Peeling off like holes C: 50% or more peeling D: 50% or more peeling <Bubbling Test 2 Glass Bubble formation on the baked enamel surface was observed with the naked eye and judged according to the following criteria.

○: No foaming at all Δ: Slight foaming The results are shown in Table 1.

Table 1 From Table 1 above, it is clear that according to the method of the present invention, it is possible to obtain a glass enamel-baked ordinary steel sheet product that foams easily and is highly adhesive.Example 2 Similar to Example 1, degreasing and activation were performed. The same ordinary steel plate that has been
+7-dininto bath, bath temperature s o 'c, current density 20A/d7)? Electroplating was carried out for 2 and 10 minutes, followed by washing with water and drying to prepare test plates.

Next, each of the above test plates was glazed with a slurry made by mixing and stirring 80 parts by weight of R J3 La Scala 2114 (Red) J paste manufactured by Jitsukei Pharmaceutical Industries Co., Ltd. with 20 parts by weight of ethanol. After drying at 50'C for 20 minutes,
Baked at 610'C for 3 minutes. Each product sample obtained after air cooling was subjected to the same test as in Example 1, and the results were as shown in Table F, Table 2.

In addition, regarding the product sample 514' obtained by setting the electric plating time to 30 minutes in the above, and then surface-plasting the obtained test plate with Emery Paperna 240, glazing and firing in the same manner. The same test results are also listed in Table 2.

Table 2 [Note] *... The chrome plating surface is made to last.

From Table 2 above, as with Table 1, it can be seen that by the present invention, glass enamel-baked one-way steel products with no bubbling and excellent adhesiveness can be obtained.

Example 3 In Example 2, the plating time was 4 minutes (plating thickness 0.
52 μm), and the obtained test plate was
[High school glass/
Based on Table 4-8 of ``Haurou 2'', Table 4-8 of Titanium Gusuri, we created four types of each titanium song, and created this frit 1.
Add 6 parts by weight of clay and 0.25 parts by weight of sodium nitrite to the soft part of 00, and pull each slip with 50 parts by weight of water.
mg, on a board with dimensions 60 x 100 vrtn)
After being glazed and dried, it was fired at 850"C for 2.5 minutes.

The product thus obtained showed no bubbles at all on the surface of the wax, and had very poor adhesion.

Example 4 The same steel plate pretreated (degreased and activated) as in Example 1 was treated with a low-temperature chromium plating solution <cro3
soyyg, tt2so4o, 5yyp and Ma2SI
F60.5y/e), bath temperature 50C, ra: lightning degree 30
Chrome plating for 5 minutes at A/dtd
(0.58 pm), washed with water and dried to prepare a sample &.

On the above sample board, use Price Co.'s f-Yoru painting paint rlO.
U7 CRtd)J, rl 009 (0
ranyt ) J and rl 012 CGrttPt
) J is manufactured by Jitsukei Pharmaceutical Industry Co., Ltd.
Paint made into a paste with Geo-oil + 9028J, 200
It was screen-printed with a mesh floral pattern and glazed. After drying, it was fired at 7.30"C for 3 minutes and cooled in air to obtain a glass enamel-baked common steel product of the present invention.

The obtained product was subjected to the same impact resistance, heat shock resistance, and foaming tests as in Male Side 1, and all of the results were very good, indicating that it was a unique and excellent partially decorated product.

Example 5 The same suitable steel plate as in Example 1 was treated with 100 y/y of persulfuric acid.
Brush
) and pretreated (degreased, activated) in the same manner as above.

Next, crO3350y was added to the +IIL treated ordinary steel sheet.
/e, H2so42.2y 7g and Cr 0.
Crack-free plating (plating thickness 0.52 ttm) was performed in a plating bath with a composition of 5 fl/l at a bath temperature of 55 C and a current density of 30 A/dad for 4 minutes, or L rO3190
'/g, //2SOa l -1f/l and #
a 2SIFs b -0' / 6 microcrack plating for 8 minutes at a bath temperature of 45"C and an X flow density of 1.5A/dyrl (plating thickness 0.42μ
m), washed with water and dried to prepare a test plate.

Each test plate was coated with 1J lath enamel [Stain Color 1'/E L-42 (
H1at4) 80 parts by weight of J paste and 2 parts by weight of ethanol
A slurry mixed with 0 parts by weight was spray coated and glazed, dried, fired at 720'C for 3 minutes, and cooled in air to obtain a product of the present invention.

As a result of the same test as in Example 1, each of the obtained products was found to have no foaming, almost the same excellent JR contact properties, and to have sufficient quality for practical use (hereinafter -F).

Claims (1)

[Claims] ■ Direct-hanging is a manufacturing method that is associated with glass enamel baking, which is characterized by applying electrochromium plating to ordinary steel with a carbon content of 0.03% or more, and then applying glass enamel.