JPH10273688A - Water-soluble cold rolling oil agent for stainless steel plate and rolling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject oiling agent exhibiting a low viscosity and an excellent lubricating property, capable of reducing an adhesion amount and the generation of seizing, and useful for producing highly lustrous stainless steel plates by a high speed rolling method by compounding a specific base oil, a surfactant and an extreme-pressure agent. SOLUTION: This water-soluble cold rolling oil agent comprises (A) a base oil comprising a mineral oil, a synthetic water (e.g. having 15-30 carbon atoms) or a synthetic hydrocarbon oil and having a viscosity of <=15 mm<2> /s, preferably 4-6 mm<2> /s, at 40 deg.C, (B) a surfactant such as a nonionic surfactant (e.g. a sorbitan surfactant having an HLB of >=13) or an anionic surfactant, and (C) an extreme- pressure agent such as a sulfur-based extreme-pressure agent having a sulfur content of >=10 wt.% and a phosphorus-based extreme-pressure agent having a phosphorus content of >=5 wt.%. The oiling agent preferably contains the components B and C in amounts of 5-30 wt.% and 1-10 wt.%, respectively, based on the whole amount of the oiling agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-soluble cold rolling oil agent for stainless steel sheets and a cold rolling method using the same.

[0002]

2. Description of the Related Art Stainless steel sheets are often used in parts that are easily visible, such as building materials and outer panels of machines, because they have good gloss and are resistant to rust.
Therefore, a stainless steel plate having always high gloss is required. When a rolling oil having a high viscosity is used at the time of cold rolling of a stainless steel plate, a large number of oil pits called oil pits are generated on the surface of the material, and the gloss is impaired. To obtain a high-gloss stainless steel sheet, use a rolling mill with a small roll diameter, and use a rolling oil based on mineral oil with a low viscosity and relatively high flash point without diluting it with water. The surface was oiled and rolled. By this method, the rolling oil drawn between the roll and the material becomes uniform and thin, eliminating oil pits called oil pits generated on the surface of the material, and making it possible to produce a stainless steel sheet having good gloss. there were. However, such a conventional water-insoluble cold rolling oil for stainless steel sheets has a low viscosity, so that the oil film thickness is small and a large amount of heat is generated due to friction. In addition, since the cooling effect is low, the surface temperature of the material reaches nearly 200 ° C. by rolling, which may exceed the flash point of rolling oil, in which case there is a risk of fire. In addition, 10
When rolling is performed at a high speed of about 00 m / min, the temperature of the material surface is further increased, and the risk of fire is further increased. Therefore, even a rolling mill (for example, a cluster mill) having a small roll diameter and capable of high-speed rolling is 600 m. It is currently rolling at around / min. In order to reduce the risk of fire during rolling, it is effective to use a water-soluble cold rolling oil as used in a tandem rolling mill. However, the water-soluble cold rolling oil used in the tandem rolling mill is excellent in the cooling effect, but the emulsion has a large particle size of 3 to 10 μm, and even if the viscosity of the rolling oil is low, the oil agent is applied to the roll or the material. Due to excessive adhesion, it was not possible to obtain a stainless steel sheet having satisfactory surface properties (excellent gloss and no uneven gloss). Furthermore, in order to maintain the glossiness using a water-soluble rolling oil, it is necessary to keep the amount of adhesion small and keep it uniform. However, when the oil film becomes thin, burn-in (heat scratch) of the material surface occurs. There was a problem that it became easier.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a water-soluble cold-rolling oil agent for stainless steel sheets which has a low viscosity, can reduce the amount of adhesion, has excellent lubricity, and does not cause seizure (heat scratch). To provide. Another object of the present invention is to provide a water-soluble cold-rolling oil agent for a stainless steel sheet that can be rolled at high speed and can obtain a stainless steel sheet having good gloss. Still another object of the present invention is to provide a method for rolling a stainless steel sheet using the above water-soluble cold rolling oil.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a base oil comprising at least one selected from the group consisting of mineral oil, synthetic ester, and synthetic hydrocarbon oil,
Is achieved by a water-soluble cold-rolling oil agent for stainless steel sheets containing a surfactant and an extreme pressure agent, having a viscosity of 15 mm ² / s or less.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The base oil used in the present invention is preferably one which can lower the viscosity of the entire oil agent, and contains at least one selected from the group consisting of mineral oils, synthetic esters, and synthetic hydrocarbon oils. The viscosity at 40 ° C. of the base oil of the present invention is 1
It is 5 mm ² / s or less, preferably 10 mm ² / s or less, more preferably 7 mm ² / s or less, most preferably 4 to 6 mm ² / s. If the viscosity of the base oil is high, the viscosity of the oil agent including the additive becomes high, and good surface gloss cannot be obtained. 4 mm ² / s
In the case below, the oil film becomes too thin and seizure easily occurs, which is not preferable. Mineral oils include, for example, spindle oil, machine oil, etc., and the difference between the initial distillation temperature and the end temperature is 3
Those having a high degree of purification of 0 ° C. or lower are preferred. The viscosity of the oil agent containing the additive at 40 ° C. is 20 when the above base oil is used.
mm ² / s or less, preferably 10 mm ² / s or less.

As the synthetic ester, the total carbon number is 15 to
30, more preferably 15 to 25.
More specifically, the number of carbon atoms is 22 or less (for example, 10 to 1
An ester (monoester, diester, triester, etc.) of the aliphatic carboxylic acid or aromatic carboxylic acid or carbonic acid of 4) with an aliphatic alcohol having 4 to 12, preferably 10 or less carbon atoms. For example, methyl oleate, ethyl oleate, butyl oleate, butyl laurate, 2-ethylhexyl laurate, butyl stearate, 2-ethylhexyl stearate, butyl palmitate, 2-ethylhexyl palmitate, dioctyl succinate, dioctyl carbonate , Di-2-ethylhexyl sebacate, di-2-ethylhexyl azelate, di-2-ethylhexyl phthalate, pentaerythritoldiolate, trimethylolpropane triolate and the like. Examples of the synthetic hydrocarbon include low-molecular-weight poly-α-olefin (PAO), low-molecular-weight polybutene, and alkylbenzene.

The surfactant used in the present invention is not particularly limited as long as it can emulsify a base oil.
A nonionic surfactant and an anionic surfactant. More preferred are nonionic surfactants, and most preferred are sorbitan surfactants. Sorbitan-based surfactants have the advantage that they stabilize the particles of the rolling oil and are less susceptible to contaminants such as tramp oil. Various sorbitan surfactants (having an HLB of 1.8 to 17) are commercially available, and in the present invention, these are used alone or in appropriate combination. In this case, the HLB of the sorbitan surfactant is 10
The above is preferred, and more preferably 13 or more. HL
When a surfactant having a B of 13 or more is used in an amount of 3% by weight or more,
The rolling oil particles can be finely and stably held, and the amount of adhesion can be kept uniform and small. When there is not sufficient emulsifying property, even if the viscosity is low, the adhesiveness becomes uneven during use and uneven gloss is caused, which causes a problem.

Examples of the sorbitan-based surfactant include sorbitan fatty acid esters and polyoxyethylene sorbitan fatty acid esters, and more specifically, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monooleate, and sorbitan monool. Stearate, sorbitan triolate, sorbitan sesquiolate, sorbitan distearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monostearate, polyoxyethylene Sorbitan triolate, polyoxyethylene sorbitan tristearate and the like can be mentioned.

Examples of other nonionic surfactants that can be used in the present invention include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitol fatty acid ester, and polyoxyethylene glyceride fatty acid. Esters and the like. As the anionic surfactant, those soluble in a base oil, for example, sodium petroleum sulfonate, sodium aromatic sulfonate, sodium dialkyl sulfosuccinate and the like are preferable. The amount of the surfactant to be used is preferably 5 to 30% by weight, more preferably 10 to 30% by weight, most preferably 15 to 25% in the rolling oil (rolling oil before dilution with water).
% By weight.

As the extreme pressure agent used in the present invention, general sulfur-based and phosphorus-based extreme pressure agents can be used. Preferably, a sulfur-based extreme pressure agent having a sulfur content of 10% by weight or more and a phosphorus content are used. 5
It is a phosphorus-based extreme pressure agent by weight% or more. Preferred examples of such sulfur-based extreme pressure agents include sulfurized fats (eg, sulfurized lard, sulfurized soybean oil, sulfurized rapeseed oil, sulfurized olefins, lanolin sulfide), sulfurized mineral oils, sulfurized synthetic oils (eg, sulfurized synthetic esters), Polysulfides (for example, didodecyl polysulfide, dibenzyl polysulfide) are mentioned, and those having a sulfur content of 10% by weight or more are particularly preferable. Preferred examples of the phosphorus-based extreme pressure agent include:
Phosphate (for example, dialkyl acid phosphate such as butoxyethyl acid phosphate, dibutyl phosphate, dialkyl phosphate such as dioctyl phosphate), phosphite (for example, triethyl phosphite, tributyl phosphite, trioctyl phosphite, tridecyl phosphite, tridecyl phosphite, Triphenyl phosphite, tricresyl phosphite, tristearyl phosphite, dialkyl hydrogen phosphite (for example, dilauryl hydrogen phosphite), diaryl hydrogen phosphite (for example, diphenyl hydrogen phosphite) and the like. Of these, those having a phosphorus content of 5% by weight or more are particularly preferred. With a sulfur-based extreme pressure agent having a sulfur content of less than 10% by weight or a phosphoric acid ester having a phosphorus content of less than 5% by weight, it is difficult to form a favorable extreme pressure film on the surface of stainless steel having low reactivity.
Sulfur-phosphorus extreme pressure agents such as dialkyldithiophosphates and thiophosphites can also be used. The amount of extreme pressure agent used is
In the rolling oil (rolling oil before dilution with water) of the present invention, preferably 1 to 10% by weight, more preferably 2 to 7% by weight.
It is. If it is less than 1% by weight, seizure may occur, and it may be used in an amount exceeding 10% by weight, but it is not economical because the effect is not further improved.

The rolling oil of the present invention may contain, if necessary, a phenolic or amine antioxidant, an oily agent such as an aliphatic carboxylic acid or an aliphatic alcohol, an amine salt of an aliphatic carboxylic acid, or a succinic acid or the like. Rust inhibitors and the like may be added. The amount of these additives used is about 0.1 to 10% by weight in the rolling oil (rolling oil before dilution with water). The rolling oil agent of the present invention can be easily produced by adding other components to a base oil, heating and dissolving at about 50 to 60 ° C., and stirring.

The rolling oil agent of the present invention is diluted with water so as to become 1 to 10% by weight, for example, about 5% by weight, to form a rolling oil agent emulsion. Supplied to The supply amount is suitably about 1000 to 6000 m ³ / min.

[0013] The rolling oil of the present invention has an average particle diameter of 3 µm when diluted with water so as to be 5% by weight.
m, particularly preferably 0.5 to 3 μm. More preferably, it is 1.0 to 2.5 μm. By thus reducing the average particle size of the emulsion particles, it is possible to obtain good surface properties (glossiness) and lubricity even when rolling at a high speed (for example, 800 m / min or more). When the average particle size of the emulsion particles is large, the amount of the rolling oil agent attached increases, causing uneven adhesion and the like, and may lower the glossiness of the stainless steel sheet. Rolling oil agent of the present invention,
It is also applicable to ferritic stainless steel sheets and austenitic stainless steel sheets.

[0014]

The present invention will be described in more detail with reference to the following examples. [Examples 1 to 17 and Comparative Examples 1 to 7] Each component (weight ratio) was added to the base oils shown in Tables 1 to 3, dissolved by heating, and mixed by stirring to prepare a rolling oil. The rolling oil was diluted with water to a concentration of 5% by weight, and various characteristics were examined using the diluted liquid. A commercially available cold-rolling oil agent for a water-insoluble stainless steel sheet was used as Comparative Example 7. The viscosity is a kinematic viscosity of a base oil or an oil agent (before dilution) measured at 40 ° C. with a JIS K-2283 Ubbelohde viscometer. The average particle diameter is obtained by diluting the rolling oil agent with ion-exchanged water so as to be 5% by weight. K. After stirring at 8000 rpm for 3 minutes with a homomixer MARKII2.5, the measurement was performed using a Coulter Multisizer (manufactured by Coulter) at an orifice diameter of 30 μm.

The emulsification stability was determined by adding 500 ppm of ultrafine iron powder (200 mm, manufactured by Vacuum Metallurgy Co., Ltd.) to 400 ml of the above diluted solution.
Was added, and T.P. K. It was determined by the change in particle size (A) after stirring at 8000 rpm for 3 minutes with a homomixer MARKII2.5. A = particle size after addition of iron powder (μm) −particle size before addition of iron powder (μ
m) Judgment: ＝= 1 μm or less Δ = 1 μm or more and less than 2 μm × = 2 μm or more The pH is a value at 50 ° C. of an emulsion diluted with water to 5% by weight.

The gloss and rollability were evaluated by using a SUS430 pickling coil made of a ferritic stainless steel sheet under the following conditions, and evaluating the gloss, the rolling load, and the seizure limit rolling reduction. Rolling conditions Test material: SUS430 Hot rolled, pickled material, thickness 3.2 mm, width 50 mm, load 280 kg Rolling roll: material and hardness SUJ-2, Hs = 91-93 Dimensions φ100mm × 200mmW (2Hi: BURφ250mm) Surface roughness Ra: 0.13μm Rolling conditions: after 9 passes rolling Finished plate thickness 0.38mm Rolling reduction 22% each pass Rolling speed 1-2 passes 400m / min 3-5 passes 600m / min 6-7 passes 800m / min 8 ~ 9 passes 1000 m / min The commercially available water-insoluble rolling oil of Comparative Example 7 is 3 to 9 passes 600 m
/ Min.

[0017] Burn-in limit rolling reduction: 25% reduction in 5th pass, 2
The seizure state was observed at 7.5% and 30%, and the rolling reduction at which seizure did not occur was defined as the seizing limit rolling reduction. The glossiness, rolling load, and seizure limit rolling reduction must be equal to or higher than that of a commercially available water-insoluble rolling oil.

[0018]

Table 1 Example 1 2 3 4 5 6 7 8 9 Base oil Mineral oil 1 80-19 33 32 11 51-25 2-30-------Synthetic ester 1-46--50 68--15 2 − − − − − − − 25 − − 4 − − 30 40 − − − − 78 − Synthetic hydrocarbon 1 − − 30 − − − − − − 40 Surfactant 13 5 3 3 3 2 3 4 3 2 2 5 7 6 6 3 5 6 7 6 3 4 4 4 4 4 4 1.5 4 4 4 − − − − − − 2.5 − − 5 2 2 − 3 5 − − − − 6 − − − − − 4 5 4 2 7 1 − 1 1---- 18 2 3 4 3 1 2 2 2 2 Extreme pressure agent 1 2------- 3 2-1-------3--25----- 6 −2 1 2 2 2 2 2 − BHT 1 − − − 1 1 1 − − Base oil viscosity (mm ² / s) 4.8 6.0 5.2 4.9 4.9 5.0 4.8 5.0 5.6 Oil viscosity (mm ² / s) 8.6 8.9 9.6 8.7 8.6 8.8 7.6 9.2 9.6 average particle diameter (μm) 1.9 2.4 2.3 2.1 1.5 2.3 2.6 2.4 2.6 emulsification stability ○ ○ ○ ○ ○ ○ ○ ○ ○ pressure during rolling test Oil concentration (%) 5.0 5.0 5.0 5.0 7.0 5.0 5.0 5.0 5.0 rolled gloss ○ ○ ○ ○ ○ ○ ○ ○ □ rolling load (9 pass meter) △ □ ○ □ ○ ○ □ ○ ○ seizure limit rolling reduction (% ) 25 27.5 27.5 30 25 25 25 25 25

[0019]

Table 10 Example 10 11 12 13 14 15 16 17 Base oil Mineral oil 1 37---64 57 56-3-------30 Synthetic ester 1-------443--- − 20 − − − − 4 30 − − 79 − − − − − 5 − 60 60 − − − − − 6 − − − − − − 20 − − 7 − − − − − − −20 − Synthetic hydrocarbon 1 − 19 24 − − − − − Surfactant 1 2 5 2 2 2 2 2 2 2 3 4 5 3 3 3 4 4 3 3 3 4 3 4 3 4 4 4 5 ... ... ... ... ... ... ... ... - 7 2 - - 1 - - 2 2 8 3 2 - - 1 3 2 2-pole pressure agent 3 - - - - - 3 3 3 4 3 - - 1 2 - - - 5 - - 4 - - 3 3 3 6 3 2 − − − − − − − 7 − − − 4 − − − − 8 − − − − 2 − − − BHT − − − − − − 1 − − Oleyl alcohol 8 − − 5 − − − − Viscosity of base oil ( ^{mm 2 / s) 5.0 7.4 7.1} 5.0 4.9 6.3 12.4 7.2 oil viscosity ^{(mm 2 / s) 9.5 8.6} 8.9 8.3 8.7 8.9 15.2 10.7 average Diameter (μm) 2.2 2.5 2.9 2.2 2.6 2.4 2.9 1.1 rolling oil concentration during emulsion stability ○ ○ △ ○ ○ ○ ○ ○ rolling test (%) 5.0 5.0 5.0 5.0 7.0 5.0 3.0 10.0 glossiness of the rolled material ○ ○ ○ ○ ○ ○ ○ ○ Rolling load (9-pass total) ○ ○ ○ ○ ○ ○ □ □ Critical rolling reduction (%) 30 25 27.5 27.5 25 25 30 30

[0020]

Table 3 Comparative Example 1 2 3 4 5 6 7 Base oil Mineral oil 1 -20------ 2 ---48 46--428-----61-Synthetic ester 1-60 88---- 4 − − − − − − 20 − 750 − − 30 30 − − Surfactant 1 4 4 4.5 − 4 3 − 2 7 5 3 − 4 4 − 3 4 1 3.5 − 7 3 − 5 3 7 − 7 4 4 −6 − − 14 − − − 7 − − − − − 2 − 82 3 3 − 52 2 − − Extreme pressure agent 2 − − − − 4 − − − 3 − − − 23 3 − 62 − − − − − − Base oil viscosity (mm ² / s) 72 5.0 5.2 18.6 17.2 16.5 − Oil viscosity (mm ² / s) 92.6 9.7 9.7 30.6 27.3 23.6 7.6 Average particle size (μm) 3.0 2.8 2.5 2.6 2.3 2.6 − Emulsion stable ○ ○ × × ○ □ − Lubricant concentration in rolling test (%) 5 5 5 5 5 5 100 Gloss after rolling test × □ △ □ △ △ ○ Rolling load (9 pass total) ○ × □ ○ ○ ○ □ Sintering limit reduction (%) 25 22 22 27.5 25 25 25

Mineral oil 1: Viscosity at 40 ° C. 4.8 mm ² / s Mineral oil 2: Viscosity at 40 ° C. 6.8 mm ² / s Mineral oil 3: Viscosity at 40 ° C. 8.7 mm ² / s Mineral oil 4: Viscosity at 40 ° C. 22 mm ² / s s Synthetic ester 1: Methyl oleate (viscosity 4.3 mm at 40 ° C)
² / s) Synthetic ester 2: butyl laurate (viscosity 3.7 mm at 40 ° C)
² / s) Synthetic ester 3: butyl stearate (viscosity 6.7 at 40 ° C)
mm ² / s) Synthetic ester 4: 2-ethylhexyl laurate (40 ° C
5.2 mm ² / s) Synthetic ester 5: 2-ethylhexyl stearate (40
Viscosity at 9.3 mm ² / s) Synthetic ester 6: di-2-ethylhexyl sebacate (40
Viscosity at 10.6 mm ² / s) Synthetic ester 7: trimethylolpropane triolate (viscosity at 40 ° C. 48 mm ² / s) Synthetic hydrocarbon 1: polyα-olefin (viscosity at 40 ° C. 5.9
mm ² / s) Synthetic hydrocarbon 2: poly-α-olefin (viscosity 12 m at 40 ° C)
m ² / s) Surfactant 1: Sorbitan monooleate (HLB 4.7) Surfactant 2: Polyoxyethylene sorbitan trioleate (HLB 10.0) Surfactant 3: Polyoxyethylene sorbitan monooleate (HLB 15.0) Surfactant 4: Polyoxyethylene sorbitan monolaurate (HLB 16.7) Surfactant 5: Polyoxyethylene alkylphenol ether (HLB 13.0) Surfactant 6: Polyoxyethylene alkyl ether (H
LB 10.8) Surfactant 7: Sodium dialkyl sulfosuccinate Surfactant 8: Sodium petroleum sulfonate Extreme pressure agent 1: Lard sulfide (10.5% sulfur) Extreme pressure agent 2: Synthetic ester of sulfur (10.8% sulfur) Extreme pressure Agent 3: dialkyl polysulfide (22% sulfur content) Extreme pressure agent 4: dialkyl polysulfide (38% sulfur content) Extreme pressure agent 5: trioctyl phosphite (7.4% phosphorus content) Extreme pressure agent 6: dilauryl hydrogen phosphite Extreme pressure agent 7: tricresyl phosphite (phosphorus content 10.0%) Extreme pressure agent 8: tristearyl phosphite (phosphorus content 3.7%)
%) BHT: dibutylhydroxytoluene

[0022]

The rolling oil of the present invention has a low viscosity, can reduce the amount of adhesion, is excellent in lubricity, can be rolled at high speed without generating seizure (heat scratch), and has good gloss. Can be rolled.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10M 129: 16 129: 68 135: 04 137: 04) C10N 20:02 30:02 30:04 30:06 30:08 40: 24 (72) Inventor Hideo Yamamoto 4-5-33 Kitahama, Chuo-ku, Osaka City Inside Sumitomo Metal Industries Co., Ltd. (72) Inventor Satoshi Matsushita 4-5-33 Kitahama, Chuo-ku, Osaka City Sumitomo Metal Industries Co., Ltd. Inside

Claims (8)

[Claims] 1. A base oil comprising at least one selected from the group consisting of a mineral oil, a synthetic ester, and a synthetic hydrocarbon oil, and the base oil has a viscosity at 40 ° C. of 15 mm ² / s or less,
A water-soluble cold-rolling oil agent for stainless steel sheets, containing a surfactant and an extreme pressure agent. 2. An oil agent containing an additive having a viscosity at 40 ° C. of 20
The oil agent according to claim 1, which has a value of not more than mm ² / s. Wherein the base oil is, 40 ° C. mineral oil viscosity below 7 mm ² / s, and 40 ° C. synthetic ester viscosity below 7 mm ² / s, and
The oil agent according to claim 1, comprising at least one selected from the group consisting of synthetic hydrocarbon oils having a viscosity at 40 ° C. of 7 mm ² / s or less. 4. The oil agent according to claim 1, wherein the synthetic ester has 15 to 30 carbon atoms. 5. The extreme pressure agent according to claim 1, wherein the extreme pressure agent is a sulfur extreme pressure agent having a sulfur content of 10% by weight or more and / or a phosphorus extreme pressure agent having a phosphorus content of 5% by weight or more. The oil agent according to claim 1. 6. The oil agent according to claim 1, wherein the surfactant is a nonionic surfactant or an anionic surfactant. 7. The oil agent according to claim 1, wherein the surfactant is a sorbitan surfactant. 8. A method for rolling stainless steel, comprising using the oil agent according to claim 1 as a rolling oil emulsion having an average particle size of 0.5 to 3 μm.