JPH08225795A - Rolling oil for stainless steel sheet - Google Patents

Abstract

PURPOSE: To form a coating film on a work roll in an early stage, eliminate the unevenness and enable the high-speed rolling of a stainless steel sheet excellent in luster at a speed as high as >=700m/min. CONSTITUTION: This rolling oil for stainless steel sheets is an emulsion of a rolling oil stock solution obtained by blending a base oil which is a synthetic ester with 3-10wt.% salt of a mono- or a dialkyl ester of orthophosphoric acid or/and phosphorous acid with an alkylamine. Furthermore, 0.005-0.1wt.% 4-18C alcohol and/or one or more selected from the group consisting of hydrogen peroxide, peracetates, perbenzoates, nitrates and nitrites is added into the emulsion or 0.5-5wt.% thereof are added into the rolling oil stock solution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-soluble rolling oil for stainless steel sheets, which can be used for high speed cold rolling of high gloss stainless steel sheets.

[0002]

2. Description of the Related Art In general, cold rolling of a stainless steel sheet (hereinafter also simply referred to as a steel sheet) requires that a rolled product have a high surface gloss, and that a rolled stainless steel sheet has a high deformation resistance. In addition, a Sendzimir mill having a small diameter work roll has been used because it is easy to work and harden, so that a small amount of rolling oil is introduced and a high rolling pressure can be obtained.

As the rolling oil, a water-insoluble rolling oil containing a low-viscosity mineral oil as a base oil, or a rolling oil obtained by solubilizing the water is used. However, the Sendzimir mill has a complicated rolling mill structure with 20 rolls, and the work roll has a small roll diameter of 60 to 80 mm.Therefore, the rolling speed is restricted and the productivity is low. was there.

Therefore, in recent years, in order to improve the productivity of the cold rolling of stainless steel sheets, the rolling mill has a simple structure and an excellent shape control function, and a 12-roll cluster mill (roll diameter: 80). (~ 120 mm) was developed,
Regarding rolling oil, a water-soluble rolling oil based on a highly lubricating synthetic ester as shown in JP-A-3-19217 and JP-A-4-118101 has been developed. Attempts to increase speed have been made.

When high-speed rolling of 700 m / min or more is performed, seizure flaws occur due to insufficient cooling and insufficient lubricity when water-insoluble mineral oil rolling oil is used.
Furthermore, there was a problem that the rolling oil was ignited in the case of a breakage accident. Further, in the case of high lubricity, the amount of oil introduced between the rolling rolls and the rolled material, that is, the roll bite increases, which causes a problem of deterioration of gloss. Moreover, in this case, the problem of ignition is serious due to the large amount of oil.

In the case of the water-soluble rolling oil as described above, the risk of ignition accident is solved, but the cooling property is increased,
There is a problem that the viscosity of the rolling oil on the roll bite becomes higher than that of the water-insoluble rolling oil, the oil film becomes thick, and sufficient glossiness cannot be obtained. In particular, in the case of water-soluble rolling oil, the occurrence of a blackish brown coating film on the surface of the rolling roll, which was observed when the water-insoluble rolling oil was used, was small, and even if it occurred, unevenness in the width direction was generated, which was sufficient. The lack of gloss was a major problem.

Although the mechanism of formation of this coating film has not been fully clarified, it has been found that the coating substance is an oxide of a rolling material component. It has also been found that the roll surface becomes smooth due to the formation of the coating film.

By the way, in the conventional low speed rolling with the Sendzimir mill, the coating film on the roll is extremely easy to be generated and evenly occurs in rolling of several tens of meters. Therefore, the work roll is replaced with a new roll in the final pass of rolling. However, there was no problem in glossiness. Especially in the rolling that emphasizes glossiness, if the roll has a flaw, the roll is replaced in the next pass.
There was no problem as long as it was slow rolling.

However, under the situation where further improvement of rolling efficiency is required as in today's day, when high speed rolling is performed, a gloss difference is produced in the rolling longitudinal direction unless a coating film is generated immediately. The above problem has arisen, and its solution has been demanded, which has been a problem particularly when a water-soluble rolling oil is used.

As described above, in the present situation, no rolling oil or rolling method has been found which can satisfy the high lubrication performance while maintaining the high gloss performance in the rolling of the stainless steel sheet, especially in the high speed rolling.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a water-soluble rolling oil which does not have the above problems and enables high speed rolling.

More specifically, the object of the present invention is to enable early generation of a coating film, which is an oxide film for rolled material, on work rolls, to eliminate unevenness, and to roll a stainless steel plate having excellent gloss. Rolling oil and it
An object of the present invention is to provide a water-soluble rolling oil capable of rolling a stainless steel sheet at a high speed of 700 m / min or more.

[0013]

Means for Solving the Problems In the rolling of stainless steel sheets, the present inventors have proposed a rolling oil composition that reduces the amount of rolling oil introduced into a roll bite at a high speed, and an oxide film of a rolling material generated on a work roll. As a result of various studies on the formation conditions of a coating film consisting of, a thin film can be obtained by using a synthetic ester having a specific pressure-viscosity coefficient as a base oil, and the lubricity is improved by adding an amine salt of a specific phosphoric acid ester. By adding alcohol and / or hydrogen peroxide, peracetates, perbenzoates, nitrates, nitrites and other oxidation promoters to water-soluble rolling oil or water. It has been found to promote the production of.

It was also found that the pH, viscosity and emulsion particle size of the water-soluble rolling oil affect the roll coating promoting action of the oxidation accelerator. Therefore, it was found that the coating film can be generated and maintained as stably as in the case of rolling using a water-insoluble rolling oil if these conditions are controlled within an appropriate range, and the present invention has been completed.

The gist of the present invention is as follows. (1) A base oil consisting of a synthetic ester having a viscosity of 5 to 50 cSt at 40 ° C., and a mono- or dialkyl ester of an orthophosphoric acid or / and phosphorous acid having 6 to 18 carbon atoms and a carbon atom of 1
An emulsion of a stock solution of a rolling oil comprising 3 to 10% by weight of a salt with an alkylamine having 18 to 18 carbon atoms, and having 4 to 18 carbon atoms, and / or hydrogen peroxide, peracetate, perbenzoate, One or more selected from the group consisting of nitrates and nitrites is added to the emulsion in an amount of 0.005 to
0.1 wt%, or 0.5 to 5 wt% in the rolling stock solution, a water-soluble rolling oil for stainless steel sheets.

(2) The concentration of the emulsion of the rolling oil stock solution is set to 3 to 15 vol%, and alkylamine and / or
Alternatively, the water-soluble rolling oil for a stainless steel sheet according to the above (1), which is made alkaline by adding alkanolamine to have a pH of 8.5 or more.

(3) Average particle size of emulsion (d: μm)
Rolling oil viscosity (η: cSt), emulsion concentration (C: vo
l%), the water-soluble rolling oil for stainless steel sheet according to the above (1) or (2), which is less than 5 μm within a range satisfying the following formula.

[0018]

[Equation 1] 50 ≤ η × C ≤ 150 (1) However, 5 ≤ η ≤ 50, 3 ≤ C ≤ 15

[0019]

Next, the function of the present invention will be described together with the reason why the composition range of each component is defined as described above. First, it will be explained that, compared with the water-insoluble rolling oil using mineral oil as a base oil, the use of the conventional water-soluble rolling oil does not cause a stable coating film on the work roll.

Since the coating film on the roll hardly occurs even when the emulsifier is added to the water-insoluble oil to make it water-soluble, firstly, the cooling performance is increased and the viscosity of the rolling oil on the roll bite is increased. Moreover, it is conceivable that the oil film became thicker due to the increase of the rolling oil viscosity due to the rolling pressure. Therefore, in the present invention, the composition is specified so as to reduce the oil film thickness.

That is, assuming that the size of the oil film thickness of the rolling oil introduced into the roll bite inlet at the time of rolling is introduced by neat oil (stock solution of rolling oil), generally the oil film thickness equivalent of the formula (2) ( t _d ). From this, it is clear that the amount introduced is proportional to the viscosity of the rolling oil.

Also, the viscosity changes with pressure and temperature.
It is expressed as in equation (3), and since the pressure change in the roll bite is extremely large with respect to the temperature change, it is strongly affected by the pressure viscosity coefficient. Therefore, the smaller the pressure-viscosity coefficient, the smaller the introduction amount.

[0023]

[Equation 2]

Where η: viscosity at the roll bite inlet,
η _o : Viscosity at normal temperature and pressure A: Pressure viscosity coefficient, P: Pressure, B: Temperature viscosity coefficient, T:
Absolute temperature U ₁ : material speed, U ₂ : roll speed, α: biting angle,
P: Yield stress of material Therefore, in the present invention, the following base oils were basically selected.

That is, a synthetic ester having a viscosity of 5 to 50 cSt at 40 ° C. and a pressure-viscosity coefficient of preferably 12 GPa ^-1 or less was used as the base oil. If the viscosity at 40 ° C. is less than 5 cSt, the oil film becomes too thin, and since a sufficient amount of the extreme pressure additive described below cannot be introduced into the friction surface, sufficient lubricity can be obtained. Because there is no. Also, 50cS
above t, or even with a pressure-viscosity coefficient of 12 GPa ^-1
If it exceeds, even if the plate-out amount (material, oil amount adhering to the roll) described later is adjusted, the amount introduced is too large to maintain sufficient gloss of the rolled material. Preferably 7
~ 20 cSt.

In the present invention, a synthetic ester satisfying the above-mentioned viscosity condition is used as a base oil. The synthetic ester is used because the ester has a smaller pressure viscosity coefficient than mineral oil.
Excellent lubricity and synthetic ester is natural ester
This is because it is easier to obtain a high-purity product than (fats and oils), and there is less heat deterioration and oxidative deterioration due to impurities.

Examples of the synthetic ester used in the present invention are as follows. I. Lauric acid, palmitic acid, myristic acid, stearic acid, isostearic acid, oleic acid, coconut oil fatty acid,
A monoester of any fatty acid such as beef tallow fatty acid and palm oil fatty acid with any one of methyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, 2-ethylhexyl alcohol and oleyl alcohol.

II. The above fatty acids and ethylene glycol,
A monoester and / or diester with either diethylene glycol or trimethylolpropane. III. A complex ester of trimethylolpropane with a fatty acid and a dibasic acid having a structure represented by the following formula (4).

[0029]

[Equation 4]

TMP: Skeleton of trimethylolpropane DA: Dibasic acid A: Fatty acid R: Alkyl group (C ₂ H ₅ ) The dibasic acid shown here is adipic acid, azelaic acid,
It is sebacic acid, and the fatty acid is the same as the above-mentioned monoester fatty acid.

Next, an additive that improves the lubricity in a thin film state will be described. In the present invention, the amine salt of a phosphoric acid ester is an oil-based / extreme pressure agent added for the purpose of enhancing lubricity when the oil film becomes thin, and the lower limit of the carbon number of the alkyl group of the phosphoric acid ester and the carbon number of the alkylamine is set. 6 and 1 respectively, and the lower limit of their addition amount is 3
The limitation to wt% depends on the lower limit value at which the required lubricity can be obtained. The upper limit of each is that as the number of carbon atoms increases, the molecular weight increases, the viscosity increases, and the coating film on the roll does not occur stably, and further, the solubility in the base oil decreases, causing unevenness and glossiness. This is to lower the Further, if the addition amount of these exceeds 10 wt%, the amount of reaction products to the rolling agent increases, which causes stains and poor gloss.

The amine salt is used here for the purpose of facilitating the mutual effect with the alcohol and various oxidation accelerators, which have the effect of promoting the coating film formation on the roll, which will be described below. Therefore, the carbon number of the alkyl group of the phosphoric acid ester is 6 to 18, the carbon number of the alkyl amine is 1 to 18, and the addition amount of the rolling oil to the base oil is 3 to 10 wt%.

Specific examples of the phosphoric acid ester amine salt used in the present invention include orthophosphoric acid or phosphorous acid, and
Alcohols having 6 to 18 carbon atoms, such as aromatic alcohols such as phenol, cresol, butylphenol, nonylphenol, hexyl alcohol, octyl alcohol, 2-ethylhexyl alcohol, decyl alcohol, lauryl alcohol, tridecyl alcohol, oleyl alcohol, etc. Mono- and / or di-esters with any of the aliphatic alcohols, any of methylamine, dimethylamine, butylamine, dibutylamine, hexylamine, dihexylamine, octylamine, 2-ethylhexylamine, oleylamine, etc., having 1 to 18 carbon atoms It is a salt that is reacted.

Next, the additives that accelerate the roll coating film formation, which is a feature of the present invention, will be described. The coating film generated on the work roll is more likely to be generated as the rolling material and the roll temperature are higher. It is also known that the component of the coating film is the transfer of oxides of rolled material. Since it is difficult to raise the temperature of the roll and the material from the viewpoint of maintaining the lubricity, it was examined to promote the oxidation, and it was found that the following chemical substances can be used for rolling as the oxidation accelerator.

First, an alcohol having 4 to 18 carbon atoms. It has the effect of making the generated coating film dense and making it difficult to peel it off. If the carbon number is less than 4, the effect is not recognized. Further, if the carbon number exceeds 18, it becomes difficult to dissolve in the rolling oil, the effect is not uniform, and the glossiness is deteriorated.

Specifically, the following alcohols correspond to it. Butyl alcohol, hexyl alcohol, octyl alcohol, 2-ethylhexyl alcohol, decyl alcohol, lauryl alcohol, tridecyl alcohol, oleyl alcohol and the like.

Secondly, there are the following oxidizing substances,
It has a function to oxidize the surface of the rolled material or work roll in common. Hydrogen peroxide, peracetate, perbenzoate,
Nitrate and nitrite. Salts other than hydrogen peroxide are used for the purpose of preventing the rolling mills other than the rolls and the rolling material from being excessively oxidized and the composition of the rolling oil not being oxidized.

As the specific salt, an alkylamine salt having 2 to 8 carbon atoms and an ammonium salt are most preferable, and then an alkylamine salt having 10 to 18 carbon atoms, and alkali metals such as Na, K and Ca. It is salt.

To use as a rolling oil, at least one of 0.005 to 0.1 wt% in the emulsion used is
Alternatively, 0.5 to 5 wt% may be added to the rolling oil stock solution. If it is less than this range, a sufficient oxidation promoting effect does not appear. On the other hand, if the amount is too large, rust is generated in the rolled material, which is not preferable.
More preferable addition amount is 0.01 to 0.05 wt in the case of using water.
%, Or 1 to 2.5 wt% in the rolling stock solution.

Further, the oxidation accelerator of the present invention is more effective when the oil film thickness is smaller. However, the oxidation accelerator, which becomes too thin, oxidatively deteriorates the rolling oil itself. Therefore, it is necessary to appropriately adjust the oil film thickness in order to sufficiently exert the effect of the above-mentioned oxidation accelerator. Therefore, the plate-out amount will be described next.

The oil film thickness equivalent shown by the above equation (3) is when the plate out amount is sufficiently large. According to the equation (3), even if the viscosity is in the proper range, it is inevitable that the amount of introduced oil changes due to changes in rolling speed. That is, it indicates that the oil film becomes too thick when high speed rolling is performed, or the oil film becomes too thin during low speed rolling at a high pressure reduction rate. Therefore, it is necessary to adjust the plate-out amount.

Here, it is a plate-out that the undiluted solution of rolling oil adheres to the material surface and the roll, and if this amount is small, sufficient rolling oil cannot be supplied into the roll bite. It is known that the plate-out amount is affected by the emulsion particle size and concentration.

It is also known that the wettability and adhesion to the rolled material differ depending on the rolling oil composition. In the present invention,
Paying attention to the wettability and adhesiveness, the additive and emulsion concentration to be added to the rolling base oil were further investigated.

As a result, it was confirmed that by adding a specific alkanolamine and / or alkylamine, the plate-out amount can be limited without lowering the lubricity, a thin film can be formed, and roll coating can be stably generated. did.

Specifically, the alkyl group has 2 to 18 carbon atoms.
It is preferable to add the alkanolamine and / or the alkylamine having 2 to 18 carbon atoms. Moreover, it has been found that this makes the pH of the emulsion alkaline and further promotes roll coating. Its pH is above 8.5.

Next, the reason why alkanolamine and alkylamine are used and the reason why pH and emulsion concentration are limited will be explained.

(1) Alkanolamine and Alkylamine All of these are added for the purpose of increasing the hydrophilicity of the rolling oil emulsion, and have the action of reducing the particle size of the emulsion. Further, it is adsorbed on the abrasion powder generated by rolling and dispersed to prevent the coalescence with the rolling oil emulsion, thereby facilitating the removal of the abrasion powder. On the other hand, it also has the effect of improving the wettability and spreadability of the material and the roll, and making it easier for the above-mentioned phosphate ester amine salt to be supplied to the new surface generated by plastic deformation.

The lower limit of the number of carbon atoms of the alkanolamine and the alkylamine in the preferred embodiment of this example is determined from heat resistance, and if the lower limit is exceeded, sufficient performance cannot be obtained. On the other hand, the upper limit of the number of carbon atoms is to increase the solubility in water and the viscosity thereof, and to reduce the roll coatability and gloss. In addition, since these additives significantly reduce the plate-out amount when used in a large amount,
The upper limit of addition to emulsion water is 0.2%, preferably 0.02 to 0.1%. The alkanolamine or alkylamine used in the present invention will be specifically shown.

The amine includes primary amine, secondary amine, and 3
Although there are primary amines, the amine used in the present invention may be any of them. Specific chemical substances include the following.

<Alkanolamine> Triethanolamine, diethanolamine, monoethanolamine, tributanolamine, diethanolamine, monoethanolamine, trihexanolamine, trihexanolamine, dihexanolamine, monohexanolamine, trioctanolamine, dioctanolamine , Monooctanolamine, tridecanolamine,
Didecanol amine, monodecanol amine, tridodecanol amine, didodecanol amine, monododecanol amine, trihexadecanol amine, dihexadecanol amine, monohexadecanol amine, trioctadecanol amine, di Octadecanolamine, monooctadecanolamine, etc.

<Alkylamine> Monomethylamine, dimethylamine, trimethylamine, monobutylamine,
Dibutylamine, tributylamine, monohexylamine, dihexylamine, trihexylamine, monooctylamine, dioctylamine, trioctylamine,
Mono-2-ethylhexylamine, monodecylamine,
Didecatylamine, tridecatylamine, monooleylamine, dioleylamine, trioleylamine and the like.

(2) Emulsion Concentration The plate-out amount is affected not only by the particle size of the emulsion but also by the concentration. Therefore, in the preferred embodiment of the present invention, the concentration is 3 to 15 vol%. The lower the concentration, the thinner the oil film, but if it is less than 3 vol%, the oil film becomes excessively thin and the lubricity deteriorates. In addition, the relative amount of scum (a viscous material in which abrasion powder and oil are mixed) generated during rolling increases, and glossiness is reduced, so the lower limit is 3 vol%. Also, 15 vol%
If it exceeds, the oil film becomes too thick and it is difficult to form a coating film on the roll, so the upper limit was made 15 vol%.

(3) Emulsion pH Since the phosphate ester amine salt added to the base oil and various oxidation accelerators are amine salts and alkali salts, the pH of ordinary rolling oil emulsions is 5.5 to 6.5, whereas the pH of ordinary rolling oil emulsions is 5.5 to 6.5. Shows an alkalinity of 7.5 or higher. By further adding an alkylamine or an alkanolamine to water, it becomes alkaline.

There is a close relationship between the pH of the emulsion and the formation of the coating film on the roll, and the coating film is more stable and earlier on the alkaline side than on the acidic side. In particular, when the pH is set to 8.5 or higher, the formation of the coating film is significantly accelerated, so the pH is limited to 8.5 or higher.

Although the reason for this is not clear, it is considered that in the preferred embodiment of the present invention, iron and chromium become ions and elute on the acidic side, but the oxide is a stable form on the alkaline side. Finally, the optimum conditions of the relationship among the average particle size of the rolling oil emulsion, the rolling oil viscosity, and the emulsion concentration will be described.

(1) Average particle size of emulsion The particle size of the emulsion can be further reduced by adding alkanolamine and alcohol. It is necessary to reduce the oil film thickness in order to obtain sufficient gloss. In the case of emulsion, the plate-out amount greatly affects the oil film thickness,
The smaller the particle size, the thinner. Therefore, the average value is 5μ
It is preferably m or less. More desirably 2 to 4 μ
m.

(2) Limitation of Rolling Oil Viscosity and Emulsion Concentration The plate-out amount is not limited to the average particle size (d: μm) of the emulsion as described above, but the rolling oil viscosity (η: cSt) and emulsion concentration (C: (vol%) has a close relationship with them, and it is necessary to limit them by combining them.

That is, it is preferable to avoid using both of them under conditions close to the lower limit value or the upper limit value. This is because there is a risk of deviation from the target performance (oil film thickness increases) due to variations in the rolling agent shape, rolling temperature, roll material, roll surface roughness, etc.
C) was limited to the following values (50 to 150). A more desirable range is that the product (η × C) of both is 60 to 130.

[0059]

[Equation 1] 50 ≤ η × C ≤ 150 (1) However, 5 ≤ η ≤ 50, 3 ≤ C ≤ 15

[0060]

EXAMPLES The present invention will be described in more detail by way of examples. (Example 1) The diameter of the work roll and the backup roll of the material SKD11 whose diameter is 100 mm and whose surface roughness is Ra 0.05 μm
Using a 330 mm 4Hi rolling machine, the rolled material of the stainless steel plate shown in Table 1 was rolled in one pass under the rolling conditions shown in Table 2. The rolling oil used had the composition and properties shown in Tables 3 to 5.

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

[Table 3]

[0064]

[Table 4]

[0065]

[Table 5]

The easiness of forming a coating film on the roll was evaluated by the rolling length until a stable coating film was formed. The rolling length of the neat oil type conventional rolling oil of Comparative Example 1 (ratio -1) was evaluated. Rolling oil shorter than 100 m was accepted. Also,
The surface of the steel plate after 300 m rolling was observed, and the presence or absence of seizure, uneven glossiness and glossiness were measured. The gloss is Gs 45 °
A score of 450 or more was used as a pass criterion. The results are shown in Tables 6 and 7.

All of the rolling oils (Ex. 1 to Ex. 18) of the present invention produced a coating film on the roll within a rolling length of 100 m.
It can be seen that the surface gloss of the rolled material is high. It is also understood that when the emulsion concentration is 3 to 15 vol% and the pH is 8.5 or more by adding alkanolamine and alkylamine, the coating film on the roll is formed earlier and the glossiness is improved.

Further, as shown in Examples 8 to 15, when the emulsion average particle size is less than 5 μm and the product of emulsion concentration and rolling oil viscosity is in the range of 50 to 150, further roll coating film formation is achieved. It can be seen that it is possible to improve the glossiness and improve the gloss.

[0069]

[Table 6]

[0070]

[Table 7]

In a preferred embodiment of the present invention, an agent (oxidation accelerator) that promotes a coating film on a roll is added to the rolling oil emulsion, the pH is controlled to be alkaline, the rolling oil concentration and the emulsion average are averaged. It is preferable to control the particle size within a certain range, and the method is shown in FIG.

In FIG. 1, the rolling material 1 is continuously cold-rolled by the rolling mill 1. At that time, the rolling roll is fed from the header 10 provided in the rolling mill 1 to the grain size, concentration and pH.
Is adjusted and the rolling oil is supplied to the rolling rolls. The properties of the rolling oil are adjusted through an oxidation accelerator addition system, an emulsion particle size adjustment system, an emulsion concentration adjustment system, and an emulsion pH adjustment system.

First, in the concentration adjustment system, the rolling oil stock solution tank 4 enters the flow rate adjustment tank 6a through a replenishing pump (not shown). Here, the water from the water supply pipe 9 is used to adjust the dilution to a desired concentration. Reference numeral 8 indicates a densitometer. After the concentration adjustment, the pH adjusting material is sent to the rolling oil emulsion tank 2, and the pH adjusting material supplied from the pH adjusting material tank 5 via a replenishing pump (not shown) is supplied to the flow rate adjusting tank 6.
After being added to b to adjust the pH, it is sent to the rolling oil emulsion tank 2. Reference numeral 7 indicates a pH meter.

The rolling oil whose concentration and pH have been adjusted in this way is further sent to the in-line mixer 14 for adjusting the emulsion particle size through the supply pump 12, and before that, from the oxidizer tank 3. An oxidant sent through the flow rate adjusting tank 6c is mixed. Reference numeral 13 is a particle size measuring device.

As described above, according to the present invention, since the oxidation accelerator is consumed quickly and accelerates the oxidation of rolling oil, it is not supplied into the tank but is added into the supply pipe as shown in the figure. . Further, the emulsion particle size is further adjusted by the in-line mixer 14 in the header pipe shown in the figure. On the other hand, the pH and emulsion concentration are adjusted in the rolling oil tank as shown in the figure.

[0076]

The use of the water-soluble rolling oil for stainless steel sheet of the present invention enables high speed rolling, and
It is possible to generate a coating film, which is an oxide film of a rolled material, on a work roll at an early stage, eliminate unevenness, and roll a stainless steel plate having excellent gloss with high efficiency.

[Brief description of drawings]

FIG. 1 is an explanatory view of a method for adding an oxidation accelerator to a rolling oil emulsion and a rolling oil circulation supply system for adjusting / maintaining the concentration, particle size and pH of the emulsion in the present invention.

[Explanation of symbols]: Oxidation accelerator addition system: Emulsion particle size adjustment system: 〃 Concentration 〃: 〃 pH 〃 1: Rolling mill, 2: Rolling oil emulsion tank, 3: Oxidizing agent tank, 4: Rolling oil stock solution tank,
5: pH adjusting agent tank, 6a, 6b, 6c: flow rate adjuster 7: pH meter, 8: concentration meter, 9: water supply pipe, 10: header 11: rolling material, 12: pump 13: particle size measuring machine, 14: In-line mixer 15: Collection tray

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C10M 137: 10 137: 02 125: 16 129: 04 129: 22) C10N 20:00 20:02 20 : 06 30:00 30:06 30:08 40:24

Claims (3)

[Claims] 1. A base oil comprising a synthetic ester having a viscosity at 40 ° C. of 5 to 50 cSt, and a mono- or dialkyl ester of an orthophosphoric acid or / and phosphorous acid having an alkyl group having 6 to 18 carbon atoms and 1 to 1 carbon atoms. An emulsion of a rolling oil stock solution, which is prepared by mixing 3 to 10 wt% of a salt with an alkylamine of 18 and has 4 to 18 carbon atoms, and / or hydrogen peroxide, peracetate, perbenzoate, nitrate. , And one or more selected from the group consisting of nitrite, and 0.005 to 0.1 wt% in the emulsion, or 0.5 in the rolling oil stock solution.
A water-soluble rolling oil for thin stainless steel sheets, which is characterized by adding up to 5 wt%. 2. The stainless steel sheet according to claim 1, wherein the concentration of the emulsion of the rolling oil stock solution is 3 to 15 vol%, and the pH is 8.5 or more alkaline by adding an alkylamine and / or an alkanolamine to water. Water-soluble rolling oil for use. 3. The average particle size of the emulsion (d: μm)
Rolling oil viscosity (η: cSt), emulsion concentration (C: vo
l%), the water-soluble rolling oil for a stainless steel sheet according to claim 1 or 2, which has a thickness of less than 5 μm within a range satisfying the following formula. [Equation 1] 50 ≤ η × C ≤ 150 (1) However, 5 ≤ η ≤ 50, 3 ≤ C ≤ 15