JPH02310384A - Steel sheet for cold working with water soluble corrosion preventing lubricative coat - Google Patents

Abstract

PURPOSE:To produce a steel sheet for cold working with a water soluble solid lubricative coat having superior stability, lubricity and corrosion preventiveness by applying an aq. soln. prepd. by mixing water with polyethylene oxide, a water soluble corrosion inhibitor and colloid of a specified oxide or a specified aq. dispersion. CONSTITUTION:An aq. soln. consisting of 100 pts.wt. (expressed in terms of solid matter) polyethylene oxide having 2,000-40,000mol.wt., 0.5-100 pts.wt. water soluble corrosion inhibitor based on a 1-hydroxybenzotriazole compd. and contg. one or two kinds of aliphatic dicarboxylic acids, 0.5-100 pts.wt. (expressed in terms of solid matter) colloid of one or two kinds of oxides such as SiO2, Cr2O3, Fe2O3 and MgO or one or two kinds of resins such as a partially cross-linked ethylene-acrylic acid copolymer, a polyacrylic acid (co)polymer and a polyacrylic ester (co)polymer and the balance water is applied to the surface of a steel sheet, dried and solidified to form a water soluble solid lubricative coat by 0.5-5.0g/m<2> per one side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a surface-treated steel sheet for press forming.

The purpose is to have good lubricity during press forming, as well as rust resistance before and after pressing, and high temperature (40 to 40℃).
A steel sheet with excellent film stability in the temperature range (60°C) and water-soluble lubricating film, which allows the lubricating film to completely dissolve in the pretreatment process of chemical conversion treatment lines used in automobile and home appliance manufacturing. It provides:

[Prior Art] When steel sheets are subjected to deep drawing or other press forming, a method has conventionally been generally adopted in which a lubricating oil based on mineral oil is applied immediately before pressing. This oiling process is a significant hindrance to improving press efficiency, and is also one of the causes of degreasing load in the post-processing process, deterioration of the working environment in the press process, and problems with welding work in the assembly process. This is well known. In recent years, with the introduction of high-speed continuous presses, the temperature of press dies and punches has risen significantly, and press cracks caused by baked-on development have frequently occurred.Furthermore, competition for model changes in the manufacture of automobiles and home appliances has led to small parts and integral molding. , the process is progressing in a severe direction towards becoming more difficult to form.

In response to this situation, for example,
No. 44-18774, JP-A No. 58-65793, etc., a wax-like substance solidified at room temperature (including semi-solid at room temperature) which has good lubricity and excellent rust prevention properties is described in advance. If the steel plate manufacturer applies the coating to the steel plate surface, it not only satisfies the best lubrication conditions, but also saves the trouble of applying the coating just before pressing, which improves productivity for both the steel plate manufacturer and the press installer. It has been shown that the effects of reducing personnel are significant. However, even steel sheets coated with wax-like substances (hereinafter referred to as lubricated steel sheets) do not satisfy rust resistance, pressability, degreasing properties, and the like.

In other words, the recent trend toward energy saving and cost saving technology has been rapid, and conventional quality is no longer satisfactory. Taking degreasing performance as an example, the degreasing bath temperature has been lowered, the concentration has been lowered, and the time has been shortened. There is a need to improve degreasing properties.

In order to solve these problems, the present inventors
-Polyethylene oxide proposed in No. 112693 (
An aqueous solution containing 0.5 to 100 parts by weight of a water-soluble rust inhibitor with the remainder being water per 100 parts by weight of solids with a molecular weight of 2000 to 40 (100) is applied to both surfaces, and after drying, it is solidified. Water-soluble anti-corrosion lubricated steel sheets for cold working on which a water-soluble solid lubricant film of 0.5 to 5.0 g/m" per side is formed are superior to conventional lubricated steel sheets in terms of pressability, and degreasability is superior to that of water-soluble lubricants. The rust resistance is equivalent to that of conventional lubricated steel sheets using water-soluble rust preventives, making it an excellent water-soluble rust-preventive lubricated steel sheet for cold working.

However, as a result of subsequent research, the present inventors discovered that
The water-soluble anti-rust lubricant steel sheet for cold working proposed in No. 112893 has excellent film stability at room temperature, but at high temperatures (4.
It became clear that there was a drawback in the film stability in the range of 0 to 60°C, and it was found that there were difficulties in using it in a high-temperature environment.

[Problems to be Solved by the Invention] The water-soluble rust-preventing lubricant steel sheet for cold working proposed by the present inventors in JP-A-63-1121i93 has lubricating properties, degreasing properties, rust resistance, and water-soluble properties, and is superior to conventional lubrication. Although it is superior to steel plates, when used in high-speed mass-use methods, that is, continuous strip steel pressing operations,
Due to the frictional heat between the punch, die, and steel plate during pressing, the temperature of the surface of the steel plate rises to around 60°C, resulting in a high temperature (40 to 60°C).
The film peels off in the 0℃ range and builds up on the roll. This bid-up material further adheres to the steel plate and deteriorates the surface appearance of the steel plate.

The present invention improves film stability in the high temperature (40 to 60°C) range (skin 11
! The present invention provides a water-soluble rust-preventive lubricating steel sheet for cold working, which has excellent peelability), sufficient lubricity, and has a water-soluble solid lubricant film that is rust-preventive and water-soluble.

[Means to solve the problem] The gist of the present invention is as follows.

Polyethylene oxide (molecular weight 2000-40000
) Water-soluble rust preventive agent O, S ~ per 100 parts by weight of solid content of
lOO parts by weight, S l 02 * Cr 20 s +
F e 2031 ' g O * Z r 02 *
5n02. ^1.03. One type of colloid (sol) such as CaCo, etc. or 2ff1 or more in solid content of 0.5 to 100
An aqueous liquid containing parts by weight and the balance being water is applied to the surface of a steel plate, and after drying, it is solidified and the amount of water is 0.5 to 5.0 per side.
This is a water-soluble rust-preventing lubricating steel sheet for cold working, characterized by forming a water-soluble solid lubricant film of g/m'.
0.5 of the water-soluble rust inhibitor per 100 parts by weight of the solid content of
~100 parts by weight, partially crosslinked ethylene-acrylic acid copolymer resin, polyacrylic acid and its copolymer resin, polyacrylic acid ester and its copolymer resin, polymethacrylic acid and its copolymer resin, poly An aqueous liquid containing 0.5 to 100 parts by weight of an aqueous dispersion of methacrylic acid ester and its copolymer resin, etc., in solid content, and the remainder being water, is applied to the surface of the steel plate, and after drying. ,
A water-soluble rust-preventing lubricating steel sheet for cold working, characterized by solidifying and forming a water-soluble solid lubricant film of 0.5 to 5.0 g/m' per side, and polyethylene oxide (molecular weight 2000 to 4). (10
00) solid content 10o! ! 0.5 to 100 parts by weight of water-soluble rust inhibitor, partially crosslinked ethylene-acrylic acid copolymer resin, polyacrylic acid and its copolymer resin, polyacrylic acid ester and its copolymer resin, one or more aqueous dispersions such as polymethacrylic acid and its copolymer resin, polymethacrylic acid ester and its copolymer resin, and 5loz, Crz03. Fe2O3
, JO, ZrO2゜5n02. AuzOs, CaCo3
An aqueous solution containing 0.5 to 100 parts by weight of one type of colloid (sol) or 2 f1 or more in solid content, the remainder of which is water, is applied to the surface of the steel plate, and after drying, it is solidified and one-sided This is a water-soluble rust-preventing lubricating steel sheet for cold working, characterized in that a water-soluble solid lubricant film of 0.5 to 5.0 g/m" per square meter is formed.

In the present invention, the steel plate refers to a cold-rolled steel plate, plated steel, resin composite steel plate, laminated steel plate, hot-rolled steel plate, or a steel plate obtained by chemical conversion treatment.

In addition, the water-soluble rust preventive agent is mainly composed of the 1-hydroxybenzotriazole compound described in Japanese Patent Publication No. 59-22793, and contains one or two fatty acid dicarboxylic acids.
Aqueous solutions of Nos. 17 to 8 to which a surfactant is added if necessary, or other known aqueous rust preventives such as sodium nitrite, sodium nitrate, aromatic carboxylic acids, imidazoles, or one type of amino acids. It refers to a combination of two or more types and a surfactant.

[For production] The present invention will be explained in detail below.

To 100 parts by weight of polyethylene oxide having a molecular weight of 2,000 and 40,000, 25 parts by weight of a water-soluble rust preventive agent and 50 parts by weight of a colloid (sol) of 5i02 are added, and the remainder is water. It was applied to the surface of a cold-rolled steel plate for deep drawing (SP (Dull No. 80 finish) with a diameter of 0.8 mm, dried and solidified, and 1.5 g/m2 per side.
A water-soluble rust-preventive lubricating steel sheet on which a water-soluble solid lubricant film was formed was obtained.

This water-soluble anti-corrosion lubricated steel sheet was subjected to a press lubrication test and a film peeling test in a high temperature range.

The press processing lubrication test method uses a blank diameter of 25 mm from a steel plate.
Cut out a specimen of 0m+a
After examining the presence or absence of cracks, the wrinkle pressing pressure was increased to 10 t/cm" for those with no cracks, and the material was drawn to a depth of 90 mm.Evaluation is based on the drawing depth (am).
The state of necking in a part of the corner and surface flaws on the contact surface of the die were observed and evaluated. The best drawing depth is 90 mm, and the shallower the drawing depth, the lower the pressability.

A film peeling test in a high temperature range was performed from this steel plate at 100
Cut out a 100mm specimen, 30,40°50.6
Warm on a hot plate to 0℃, 30kg/100c
A load of m' was applied, and the surface was rubbed with a rubber tube of 10 cm'R at a speed of 100 cm''/sec, and the condition of the scratch marks on the surface was observed and evaluated.

Next, the colloid (sol) of stow was converted into Cr2O5゜Fe.
20s* MgO, ZrO2, 5n02. ^l*Os,
The above-mentioned water-soluble rust-preventive lubricant film was formed on the above-mentioned steel plate using the above-mentioned aqueous liquid changed to colloid (sol) of cacOs.The water-soluble rust-preventive lubricant film was then similarly subjected to a press-working lubrication test and a film peeling test in a high temperature range. I did it.

These results are shown in Table 1.

Table 1 shows water-soluble rust-preventing lubricant steel sheets (conventional product) in which a water-soluble solid lubricant film of 1.5 g/m2 per side was formed on the surface of the steel sheet using the aqueous liquid without adding colloid (sol). ) comparison test results are also listed.

As is clear from Table 1, the products of the present invention had the same or improved pressability as compared to the conventional products, and were able to secure high-temperature (40 to 60° C.) film stability that could not be obtained with the conventional products.

Even if the amount of colloid (sol) is changed from 0.5 to 100 parts by weight, or by combining various colloids (sol),
Even when the amount was varied within the range of 100 parts by weight, equivalent pressability and high-temperature film releasability could be obtained.

Next, the above-mentioned steel sheet was obtained on which the above-mentioned lubricating film was formed using an aqueous liquid in which the colloid (sol) was changed to an aqueous dispersion of a partially cross-linked ethylene-acrylic acid copolymer resin. A film peelability test was conducted.

Next, a partially crosslinked aqueous dispersion of ethylene-acrylic acid copolymer resin is added to partially crosslinked polyacrylic acid copolymer resin, polyacrylic acid ester copolymer resin, polymethacrylic acid copolymer resin, polymethacrylic acid copolymer resin, etc. Changed to an aqueous dispersion of acid ester copolymer resin.

These results are also shown in Table 1.

As is clear from Table 1, the products of the present invention had the same or improved pressability as compared to the conventional products, and were able to secure high-temperature (40 to 60° C.) film stability that could not be obtained with the conventional products.

In addition, polyacrylic acid partially crosslinked with an aqueous dispersion of partially crosslinked polyacrylic acid copolymer resin, polyacrylic acid ester copolymer resin, polymethacrylic acid copolymer resin, and polymethacrylic acid ester copolymer resin Even if the resin, polyacrylic acid ester resin, polymethacrylic acid resin, or polymethacrylic acid ester resin is changed to an aqueous dispersion, or the amount of resin is changed from 0.5 to 100 parts by weight, or the amount of resin is varied. Even when the combination was varied within the range of 0.5 to 100 parts by weight, equivalent pressability and high-temperature film peelability could be obtained.

Next, to 100 parts by weight of solid content of polyethylene oxide with a molecular weight of 2,000 and 40,000, 2 parts of a water-soluble rust inhibitor was added.
5 parts by weight, 5tO2 colloid (sol) and ethylene-
50% solid content of aqueous dispersion of acrylic acid copolymer resin.
parts by weight (sio, ethylene-based on 25 parts by weight solids)
An aqueous solution containing acrylic acid copolymer resin (solid content: 25 parts by weight), the remainder of which is water, is applied to the surface of a 0.8 mm thick cold-rolled steel plate for deep drawing (5PCE dull size 80 finish), and after drying it becomes solid. The above-mentioned steel plate with a solid lubricant film of 1.5 g/m'' per side was obtained, and a press lubrication test and a high-temperature film peelability test were conducted in the same manner.

In addition, the above lubricating film was formed using an aqueous liquid in which the aqueous dispersion of ethylene-acrylic acid copolymer resin was changed to an aqueous dispersion of polyacrylic acid copolymer resin, the above steel plate was obtained, and the same tests were conducted. Ta.

These results are also shown in Table 1.

As is clear from Table 1, the products of the present invention had the same or improved pressability as compared to the conventional products, and were able to secure high-temperature (40 to 60° C.) film stability that could not be obtained with the conventional products.

Even if you change the type and amount of colloid (sol) and the type and amount of resin, or use various combinations, the results will be equivalent as long as the solid content of colloid (sol) and resin is in the range of 0.5 to 100 parts by weight. It was possible to obtain good pressability and high temperature (40 to 60°C) film properties.

As mentioned above, 5i02. Cr2O3, 'Fe2O3, MgO
.

ZrO2,5n02. ＾9203. 1f of colloid (sol) such as CBGO3! or two or more and/or partially crosslinked ethylene-acrylic acid copolymer resins, polyacrylic acid and its copolymer resins, polyacrylic esters and its copolymer resins, polymethacrylic acid and its copolymer resins, The solid content of one or more aqueous dispersions such as polymethacrylic acid ester and its copolymer resin is 0.5 to 1.
A film was formed using an aqueous solution to which part of 001i was added.
The reason why the product of the present invention has excellent film stability at high temperatures (40 to 60°C) is thought to be because the above-mentioned colloid (sol) and the above-mentioned aqueous dispersion improve the bonding strength of the film and make it stronger. The reason why the pressability is improved is thought to be because the colloid (sol) as a film hardening agent and the aqueous dispersion also act as a lubricant as described above.

The molecular weight of polyethylene oxide is 2000 to 4000.
The reason why it is limited to 0 is because the press workability differs depending on the molecular weight of polyethylene oxide, and if it is less than 2,000, the workability decreases, and if it exceeds 40,000, the water solubility and degreasing properties of polyethylene oxide decrease.

Addition ratio of water-soluble rust preventive to 0.5 to 100 of the main component resin
The reason why it is limited to parts by weight is that if it is less than 0.5 parts by weight, the rust prevention property will be reduced, and if it exceeds 10,031 parts by weight, there will be a problem that the lubricity will be reduced.

Also, the upper limit of colloid (sol) as a film hardening agent is set to 10
Setting the amount to 0 parts by weight limits its effectiveness as a film hardening agent, and adding more than this increases cost. The reason why the lower limit is set to 0.5 parts by weight is because the effect may be weakened below this value.

Furthermore, the upper limit of the amount of resin such as partially crosslinked ethylene-acrylic acid copolymer resin as a film hardening agent was set at ioo z because its effectiveness as a film hardening agent was at its limit, and adding more would increase costs. The reason why the lower limit is set to 0.5 parts by weight is that the effect is diminished below this value.

Furthermore, if a colloid (sol) and a partially crosslinked ethylene-acrylic acid copolymer resin are added in combination, the synergistic effect will improve the effect, but the degreasing properties will decrease, so the upper limit is 10% in total.
It is 0 parts by weight. The lower limit is 0.5 part by weight in total due to the limit of effectiveness as a film hardening agent.

Polyethylene oxide is solidified at room temperature, and to form a thin film on a steel plate, a specified amount of polyethylene oxide is dissolved in a specified amount of water, a specified amount of a water-soluble rust preventive agent and a film hardening agent are added, and then sprayed. method or roll coater
It is desirable to dry with hot air of 100 tons or more immediately after application, and the dry film thickness is 0.5 g/m2 to ensure rust prevention and press formability.
The lower limit is set at 5.0 g/m2, and the upper limit is set at 5.0 g/m2, and if this is exceeded, welding properties, blocking properties, sliding properties, degreasing properties, etc. will deteriorate. The dry film thickness is controlled by the concentration of polyethylene oxide in the spray method, and by the groove width, angle, and groove depth of the grooved roll in the roll coater method.

Next, a specific example of a water-soluble rust-preventing lubricating steel sheet for cold working according to the present invention will be described.

[Example] Example-1 Solid lubricant polyethylene oxide (molecular weight 20,000
) 100 parts by weight and a water-soluble rust preventive agent (Special Publication No. 59-227
No. 93 1-hydroxybenzotriazole compound is the main component, and one or two fatty acid dicarboxylic acids are added to adjust the pH to 7.
8) as the main component and 0.25 parts by weight of a nonionic polar surfactant (polyoxyethylene alkyl ether) as the main component, and as a film hardening agent, 5 in 2 colloid (sol ) was added and dissolved in 5000 parts by weight of water at room temperature. Using this aqueous liquid,
．． A Linghong steel plate with a coil length of 8 mm x 95 Q mm was immersed at 50 m/min for 2 seconds, and then squeezed with a grooved roll and dried with hot air to give a coating amount of 2 g/l112.

Example-2 Solid lubricant polyethylene oxide (molecular weight 20,000
) 100 parts by weight and a water-soluble rust preventive agent (Special Publication No. 59-227
No. 93 1-hydroxybenzotriazole compound is the main component, and one or two fatty acid dicarboxylic acids are added to adjust the pH to 7.
8 aqueous solution with surfactant added if necessary)
The main component ratio is 25 parts by weight, and the nonionic surfactant (polyoxyethylene fatty acid ester) is 0.25 parts by main component.
50 parts by weight of ethylene-acrylic acid copolymer resin was added as a film hardening agent, and 5 parts by weight of water was added at room temperature.
000 parts by weight. 0.8 m using this aqueous liquid
mX 950mm x coil length cold rolled steel plate 50m/
After dipping for 2 seconds at 10 minutes, the sample was squeezed with a grooved roll and dried with hot air to give a coating amount of 2 g/m''.

Example-3 Solid lubricant polyethylene oxide (molecular weight 20(1(
1 (1) 10 (1 part by weight and water-soluble rust preventive agent (Special Publication Showa 5q)
-o79: 25 parts by weight of a nonionic surfactant (aqueous solution with a pH of 7 to 8 containing a t-hydroxybenzotriazole compound as the main component and one or two fatty acid dicarboxylic acids) and a nonionic surfactant (polymer Oxyethylene fatty acid ester) was added in an amount of 0.25 parts by weight based on the ratio of the main components, 25 parts by weight of ethylene-acrylic acid copolymer resin was added as a film hardening agent, and 25 parts by weight of colloid (sol) of 5102 was added. and dissolved in 5000 parts by weight of water at room temperature. Using this aqueous solution, a cold-rolled steel plate of 0.8 mm x 950 mm x coil length was immersed at 50 m/min for 2 seconds, and then squeezed with a grooved roll and dried with hot air to give a coating amount of 2 g/l112.

Conventional solid lubricant polyethylene oxide (molecular weight 20,000
) 100 parts by weight and a water-soluble rust preventive agent (Special Publication No. 59-22
No. 793 1-hydroxybenzotriazole compound as the main component, with 1 to 2 ffl of fatty acid dicarboxylic acid added and an aqueous solution with a pH of 7 to 8 and a surfactant added as necessary) to 25 parts by weight of the main component ratio. A nonionic surfactant (polyoxyethylene fatty acid ester) was added in an amount of 0.25 parts by weight as a main component and dissolved in 5000 parts by weight of water at room temperature.

0.8 mm x 950 m using this water-soluble anti-rust lubricant
A cold-rolled steel plate with a length of m x coil was immersed for 2 seconds at 50 m/min, then squeezed with a grooved roll and dried with hot air to a coating amount of 2 g/m.
It was set as 2.

Table 2 shows the results of various investigations on steel sheets for cold working coated with these films. It showed excellent results in all areas, including pressability, rust resistance, weldability, blocking properties, degreasing properties, and high-temperature film removability.

[Effects of the Invention] As is clear from the above examples, the present invention is capable of forming a film made of a limited lubricating substance, a water-soluble rust preventive agent, a surfactant, and a film hardening agent in a worked steel sheet for cold rolling. As a result, it was possible to produce a water-soluble lubricated steel sheet for cold working which has particularly excellent lubricity, water solubility, rust resistance, and high temperature film removability.

Claims (1)

[Claims] 1. Polyethylene oxide (molecular weight 2000-400
0.00) of the water-soluble rust inhibitor per 100 parts by weight of the solid content.
5 to 100 parts by weight, SiO_2, Cr_2O_3, Fe
_2O_3, MgO, ZrO_2, SnO_2, AlO
An aqueous solution containing 0.5 to 100 parts by weight of one or more colloids (sols) such as _3 and CaCo_3 in solid content and the remainder being water is applied to the surface of the steel plate, and after drying, it is solidified, A water-soluble rust-preventing lubricating steel sheet for cold working, characterized in that a water-soluble solid lubricant film of 0.5 to 5.0 g/m^2 is formed on one side. 2 Polyethylene oxide (molecular weight 2000-400
0.00) of the water-soluble rust inhibitor per 100 parts by weight of the solid content.
5 to 100 parts by weight, partially crosslinked ethylene-acrylic acid copolymer resin, polyacrylic acid and its copolymer resin,
One or more types of aqueous dispersions such as polyacrylic acid ester and its copolymer resin, polymethacrylic acid and its copolymer resin, polymethacrylic acid ester and its copolymer resin, etc. in a solid content of 0.5 An aqueous liquid containing ~100 parts by weight and the remainder being water was applied to the surface of a steel plate, and after drying, it solidified to form a water-soluble solid lubricant film of 0.5 to 5.0 g/m^2 per side. A water-soluble rust-preventing lubricated steel sheet for cold working, which is characterized by: 3 Polyethylene oxide (molecular weight 2000-400
0.00) of the water-soluble rust inhibitor per 100 parts by weight of the solid content.
5 to 100 parts by weight, partially crosslinked ethylene-acrylic acid copolymer resin, polyacrylic acid and its copolymer resin,
One or more types of aqueous dispersions such as polyacrylic acid ester and its copolymer resin, polymethacrylic acid and its copolymer resin, polymethacrylic acid ester and its copolymer resin, and SiO_2, Cr
_3O_3, Fe_2O_3, MgO, ZrO_2, S
One or more colloids (sols) such as nO_2, Al_2O_3, CaCo_3, etc. in a solid content of 0.5 to 1
An aqueous solution containing 0.00 parts by weight and the remainder being water is applied to the surface of a steel plate, and after drying, it is solidified and 0.5 to 5 parts by weight per side.
．． A water-soluble rust-preventing lubricant steel sheet for cold working, characterized by forming a water-soluble solid lubricant film of 0 g/m^2.