JPH10273689A - Water-soluble cold rolling oil for stainless steel sheet and rolling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stainless steel plate having a low viscosity, a small amount of adhesion, excellent lubricity, high speed rolling without generating seizure (heat scratch), and good gloss. To provide a water-soluble cold-rolling oil agent for stainless steel sheets capable of obtaining a stainless steel sheet, and a method for rolling stainless steel sheets using the same. SOLUTION: A water-soluble cold-rolling oil agent for a stainless steel sheet, comprising a base oil, a secondary amine, a phosphite, and a surfactant.

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.

[0003] 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. Also, since the cooling effect is low, the surface temperature of the material reaches nearly 200 ° C by rolling,
The flash point of the rolling oil may be exceeded, in which case there is a risk of fire. Further, when rolling is performed at a high speed of about 1000 m / min, the temperature of the material surface is further increased, and the risk of fire is further increased. Therefore, a rolling mill having a small roll diameter and capable of high-speed rolling (for example, a cluster mill) However, at present, rolling is performed at around 600 m / 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 gloss using a water-soluble rolling oil,
It is necessary to keep the adhesion amount small and uniform, but when the oil film becomes thin, there is a problem that seizure (heat scratch) on the material surface easily occurs.

[0004]

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.

[0005]

The object of the present invention is achieved by a water-soluble cold-rolling oil for stainless steel sheets, comprising a base oil, a secondary amine, a phosphite and a surfactant.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The base oil used in the present invention preferably contains at least one selected from the group consisting of mineral oils, synthetic esters, and synthetic hydrocarbon oils. Mineral oils include, for example, spindle oil, machine oil and the like, and those having a high degree of refining with a difference between the initial distillation temperature and the end temperature of 30 ° C. or less are preferable.

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,
Alkylbenzene and the like. Among these base oils, mineral oils having a viscosity at 40 ° C. of 10 mm ² / s or less have been conventionally used as components of water-insoluble rolling oils. The base oil of the water-soluble rolling oil agent of the present invention is preferably 40
It is desirable that the viscosity at 200 ° C. is 200 mm ² / s or less, more preferably 50 mm ² / s or less. Particularly preferred are those containing at least one member selected from the group consisting of mineral oils, synthetic esters, and synthetic hydrocarbon oils, and having a viscosity at 40 ° C. of 15 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
belongs to. When the thickness is less than 4 mm ² / s, the thickness of the oil film becomes too thin, and the seizure easily occurs.

The secondary amine used in the present invention has an effect of adjusting the pH of an emulsion obtained by diluting a rolling oil with water to an alkaline range. Preferred examples of the secondary amine include those represented by the following formula (1). (1) NHR ¹ R ^{2 In the} formula, R ¹ and R ² may be the same or different and are saturated or unsaturated, linear or branched, alkyl group (preferably having 1 to 20 carbon atoms), saturated Or an unsaturated cycloalkyl group (preferably having 5 to 18 carbon atoms) or an aryl group (preferably having 6 to 18 carbon atoms). Particularly preferred are secondary amines having 6 to 20 carbon atoms.

Specific examples of preferred secondary amines include diisopropylamine, dibutylamine, di-n-hexylamine, di-n-octylamine, dicyclohexylamine, di-2-ethylhexylamine, and diallylamine. When the number of carbon atoms is 5 or less, many of them have a low boiling point, evaporate during circulating use, and the pH of the rolling oil emulsion tends to decrease.
The effect of increasing H tends to be insufficient. In addition, primary amines and alkanolamines react with phosphites to lower their solubility in base oils, and tertiary amines have an insufficient effect of increasing pH. The amount of secondary amine used is
In the rolling oil (before dilution with water), preferably 0.1%.
It is 1 to 10% by weight, more preferably 1 to 5% by weight.

[0011] The particles of the rolling oil emulsion of the present invention are:
In order to be stable in water and to be less affected by wear powder mixed therein, it is desirable to adjust the surface potential (zeta potential) of the wear powder to have the same sign. pH 7
In the above aqueous solution, both the abrasion powder and the rolling oil emulsion particles are negatively charged and repel each other to stabilize the emulsion. Therefore, the rolling oil emulsion of the present invention has
PH of 7 or more using a secondary amine, preferably 7 to 10,
More preferably, it is adjusted to 8 to 9.

By setting the pH to the alkaline side, the surface potential (zeta potential) of the rolling oil particles becomes -20 mV or less, and the surface potential of the abrasion powder is also negatively charged. Therefore, a uniform state can be maintained without aggregation. As a result, the glossiness of the surface of the stainless steel plate is improved, and uneven glossiness can be prevented. If the pH of the rolling oil emulsion is less than 7, the surface potential of the abrasion powder is positively charged, so that the agglomeration of the abrasion powder and the rolling oil particles easily occurs, making it difficult to obtain a uniform emulsion.

The phosphite used in the present invention is preferably represented by the following formula (2), (3) or (4). (2) (R ³ O) (R ⁴ O) PH (＝ O) (3) (R ³ O) (R ⁴ O) POH (4) (R ³ O) (R ⁴ O) (R ⁵ O) R in the formula, R ³ , R ⁴ and R ⁵ may be the same or different and are saturated or unsaturated, linear or branched, alkyl groups (preferably having 1 to 20 carbon atoms), saturated or unsaturated. of,
It represents a cycloalkyl group (preferably having 5 to 18 carbon atoms) or an aryl group (preferably having 6 to 18 carbon atoms). The phosphite reacts quickly on the surface of a stainless steel plate with low reactivity, and forms a strong extreme pressure film even with a thin oil film. On the other hand, orthophosphates have high reactivity, but are easily decomposed in water and have no effect.

Preferred examples of the phosphite used in the present invention include dialkyl hydrogen phosphites (eg, dilauryl hydrogen phosphite, distearyl hydrogen phosphite) and diaryl hydrogen phosphites (eg, diphenyl hydrogen phosphite). Gen phosphite), triethyl phosphite,
Tributyl phosphite, trioctyl phosphite,
Tricresyl phosphite, tristearyl phosphite, tri-decyl phosphite, tris-tridecyl phosphite, diphenyl-monodecyl phosphite, triphenyl phosphite) and the like. The above are particularly preferred. The amount of phosphite used is rolling oil (before dilution with water)
The content is preferably 0.1 to 10% by weight, more preferably 1 to 5% by weight.

The rolling oil agent of the present invention contains a surfactant as an essential component in order to be diluted with water to form an emulsion. These surfactants may be any as long as they can emulsify the base oil, but are preferably nonionic surfactants, and anionic surfactants.
In particular, those capable of reducing the particle size of the emulsion particles to about 0.5 to 3 μm are preferable. More preferably, it is a nonionic surfactant. The HLB of the nonionic surfactant is preferably 10 or more, more preferably 13 or more.
When a nonionic surfactant or an anionic surfactant having an HLB 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 the applied oil can be kept uniform and small.

Examples of nonionic surfactants that can be used in the present invention include polyoxyethylene sorbitan ester, sorbitan fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitol Fatty acid esters and polyoxyethylene glyceride fatty acid esters are exemplified. 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 used is preferably 5 to 30% by weight in the rolling oil (rolling oil before being diluted with water).
More preferably 10 to 30% by weight, most preferably 1 to 30% by weight.
5 to 25% by weight.

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, a succinic acid or the like. Rust inhibitors, sulfurized fats and oils, and sulfur-based extreme pressure agents such as polysulfide may be added. The amount of these additives used is rolling oil (rolling oil before dilution with water)
Medium, it is about 0.1 to 10% by weight. 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 be 1 to 10% by weight, for example, about 5% by weight to form a rolling oil agent emulsion,
For example, it is supplied to a rolling roll and / or a stainless steel plate material surface by a nozzle or the like. The supply amount is 1000-
About 6000 m ³ / min is appropriate.

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.

[0019]

The present invention will be described in more detail with reference to the following examples. [Examples 1 to 11 and Comparative Examples 1 to 6] 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 6. The pH is a value at 50 ° C. of an emulsion obtained by diluting the rolling oil with 5% by weight with ion-exchanged water. The average particle diameter is obtained by diluting the rolling oil agent with ion-exchanged water so as to be 5% by weight. K. Homomixer MARKII
After stirring at 8000 rpm for 3 minutes according to 2.5, 30 minutes using Coulter Multisizer (manufactured by Coulter).
It was measured at an orifice diameter of μm. The zeta potential of the emulsion (400 ml, TK manufactured by Tokushu Kika Kogyo Co., Ltd.) was prepared by diluting the rolling oil with ion-exchanged water so as to be 5% by weight.
3 at 8000 rpm with the homomixer MARKII2.5
This is a value measured by adjusting the pH at 25 ° C. to the pH of the test oil with DELSA440sx manufactured by Coulter Corporation.

The gloss and the rollability were evaluated by using a SUS430 pickling coil made of a ferritic stainless steel sheet under the following conditions, and evaluating the gloss, rolling load, and 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 6 is 3 to 9 passes 600 m
/ Min.

[0021] 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. Glossiness, rolling load, critical reduction rate of seizure must be equal to or better than commercially available water-insoluble rolling oil

[0022]

Table 1 Example 1 2 3 4 5 6 Base oil Mineral oil VG5 -60 60 59 39 39 Butyl stearate-20 20 20--2-Ethylhexyl stearate 78---40 40 Secondary amine Dibutylamine 2.0 2.0 --- 3.0 Dicyclohexylamine--3.0 3.0 2.0- Phosphite ester Phosphite ester 1 3.0-2.0-3.0 3.0 Tributyl phosphite -2.0-2.0 -- Surfactant Sorbitan monooleate 3.0 4.0 3.0 3.0 4.0 3.0 POE Sorbitan monooleate 4.0 4.0 3.0 3.0 3.0 3.0 POE sorbitan trioleate 6.0 5.0 4.0 5.0 4.0 4.0 POE alkylphenol ether 2.0 1.0 3.0 3.0 3.0 3.0 BHT 1.0 1.0 1.0 1.0 1.0 1.0 alkenylsuccinic acid (C-15) 1.0 1.0 1.0 1.0 1.0 1.0 5% emulsion pH 8.5 8.9 9.2 8.7 8.6 9.3 Average particle size of emulsion (μm) 2.3 2.1 1.9 2.0 1.9 1.8 Zeta potential of oil agent (mV) -40 -43 -50 -40 -46 -50 Rolling oil concentration during test rolling (wt%) 5 5 5 5 5 5 Glossiness of rolled material ○ ○ ○ ○ ○ ○ Rolling load (9-pass total) ○ □ □ □ ○ ○ Limiting reduction in baking (%) 30 27.5 27.5 27.5 30 30

[0023]

Example 7 8 9 10 11 Base oil Mineral oil VG5 44----Butyl stearate-20 20--2-Ethylhexyl palmitate 40--40 40 Polyalpha-olefin-56 58 37 36 Secondary Amine Dibutylamine 0.5 4.5 2.0-3.0 Dicyclohexylamine---3.0- Phosphite ester Phosphite 1 0.5 4.5 2.0-- Tributyl phosphite---3.0 3.0 Surfactant Sodium petroleum sulfonate---4.0 3.0 Sorbitan monooleate 3.0 3.0 4.0--POE sorbitan monooleate 3.0 3.0 4.0--POE dioleate 4.0 4.0 5.0 7.0 8.0 POE alkylphenol ether 3.0 3.0 3.0 4.0 5.0 BHT 1.0 1.0 1.0 1.0 1.0 1.0 Alkenyl succinic acid (C-15) 1.0 1.0 1.0 1.0 1.0 5% the average particle diameter of pH 7.9 8.2 8.6 8.7 9.1 emulsion emulsion (μm) 2.3 1.2 0.9 2.6 1.3 oil zeta Position (mV) -22 -27 -36 -50 -47 Test rolling oil concentration (wt%) during rolling 5 2 10 1 10 rolled material gloss ○ ○ ○ ○ ○ rolling load (9 pass meter) ○ □ □ □ □ Critical rolling reduction (%) 25 30 27.5 25 25

[0024]

Table 3 Comparative Example 1 2 3 4 5 Base oil Mineral oil VG5 60 64 38 41-Butyl stearate 20 20---2-Ethylhexyl stearate-----2-Ethylhexyl palmitate--40 40- Poly α-olefin -----Secondary amine dibutylamine--6.0-- Dicyclohexylamine---2.0- Phosphite ester Phosphite ester 1 6.0 ----Tributyl phosphite-2.0--- Surfactant Sorbitan mono Olate 3.0 2.0 4.0 4.0-POE sorbitan monooleate 4.0 3.0 3.0 4.0-POE sorbitan triolate 3.0 3.0 2.0 2.0- POE alkyl phenol ether 2.0 4.0 5.0 5.0- BHT 1.0 1.0 1.0 1.0- Alkenyl succinic acid (C-15) 1.0 1.0 1.0 1.0 - pH of 5% emulsion 4.2 5.9 10.2 9.3 - average particle size of the emulsion (μm) 3.2 4.1 2.6 2.2- Zeta potential of oil (mV) +0.5 +7.3 -43 -41- Concentration of rolling oil during test rolling (% by weight) 3 3 5 5- Gloss of rolled material × × ○ ○ ○ Rolling load (9 passes) Total) ○ ○ × × □ Seal limit reduction (%) 30 25 22 22 25

Phosphite ester 1: dilauryl hydrogen phosphite sorbitan monooleate (HLB = 4.7) POE (polyoxyethylene) sorbitan monooleate (HLB = 15.0) POE sorbitan trioleate (HLB = 10.5) POE dioleate (HLB = 10.4) POE alkylphenol ether (HLB = 10.)
5) BHT: dibutylhydroxytoluene

[0026]

Industrial Applicability The rolling oil agent of the present invention can reduce the amount of adhesion, has excellent lubricity, can perform high-speed rolling without causing seizure (heat scratch), and has excellent glossiness. Can be rolled.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10M 133: 04 137: 02 129: 16 129: 68) C10N 30:02 30:04 30:06 30:08 40:24 (72 ) Inventor Hideo Yamamoto 4-33, Kitahama, Chuo-ku, Osaka City Inside Sumitomo Metal Industries Co., Ltd. (72) Inventor Satoshi Matsushita 4-5-33, Kitahama, Chuo-ku, Osaka City Inside Sumitomo Metal Industries Co., Ltd.

Claims (5)

[Claims] 1. A water-soluble cold-rolling oil agent for a stainless steel sheet, comprising a base oil, a secondary amine, a phosphite, and a surfactant. 2. The oil agent according to claim 1, wherein the base oil comprises at least one selected from the group consisting of mineral oil, synthetic ester, and synthetic hydrocarbon oil. 3. The oil agent according to claim 1, wherein the secondary amine is represented by the following formula (1). (1) NHR ¹ R ^{2 In the} formula, R ¹ and R ² may be the same or different and represent an alkyl group, a cycloalkyl group, or an aryl group. 4. The phosphite according to the following formula (2):
The oil agent according to any one of claims 1 to 3, which is represented by (3) or (4). (2) (R ³ O) (R ⁴ O) PH (＝ O) (3) (R ³ O) (R ⁴ O) POH (4) (R ³ O) (R ⁴ O) (R ⁵ O) P In the formula, R ³ , R ⁴ and R ⁵ may be the same or different and represent an alkyl group, a cycloalkyl group or an aryl group. 5. A method for rolling a stainless steel sheet, wherein the oil agent according to claim 1 is used as an emulsion, and the average particle size of the emulsion particles is 0.5 to 3 μm.