JP2693639B2 - Method for preparing rolling oil sample for evaluation - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for preparing a rolling oil sample for evaluation, and in particular, a rolling oil in a deteriorated state which is almost the same as the actual use state can be reproduced in a short time. I try to adjust with good nature.

(Prior Art) Conventionally, performance evaluation of rolling oil has often been performed in a laboratory using new oil. However, the actual usage is cyclical use in a state where a large amount of abrasion powder generated from the lubricated surface is dispersed in the rolling oil.

Such abrasion powder is generated from the new surface and is considered to have come into contact with the rolling oil in a very active state. Therefore, in the performance evaluation of rolling oil, the results obtained in the laboratory are considerably different from those in the case of actually used for a long time.

Therefore, conventionally, a method has been adopted in which the abrasion powder actually generated is extracted from the rolling oil in use and put into the rolling oil to be evaluated for testing.

(Problems to be Solved by the Invention) Cold rolling oil is required to be able to be used stably without deterioration for a long period of time, and therefore it is necessary to reproduce the same condition as the actual usage in the laboratory. Will be especially important in developing.

However, in the conventional method described above, in which the abrasion powder actually generated is extracted from the rolling oil in use and put into the rolling oil to be evaluated for testing, the same condition as the actual use condition is tested. It has not yet been reproduced in the room.

(Means for Solving the Problem) The inventors have found that the abrasion powder generated in the actual use situation is generated from the new surface by the rolling process and has a highly active surface, and is rolled without being exposed to the atmosphere. Focusing on mixing in oil, the temperature of the lubricated surface is 200 to 300 depending on the deformation heat due to plastic working and the friction heat of the lubricated part.
The present invention has been completed as a result of intensive studies on a new method for preparing a rolling oil sample in consideration of the increase in temperature to about 0 ° C.

That is, the present invention, in the rolling oil to be evaluated, after charging the powder particles of the metal to be rolled whose surface is activated without touching the atmosphere, a method for preparing a rolling oil sample for evaluation, which comprises uniformly dispersing (First invention)

The present invention also provides a method for preparing a rolling oil sample for evaluation (second invention), which comprises heating or boiling and concentrating a rolling oil mixed with powder particles of a metal to be rolled whose surface is activated in the first invention. is there.

Further, the present invention is the method for preparing a rolling oil sample for evaluation (third invention), which comprises repeating the heating or boiling concentration step in the second invention.

In the first to third inventions, as the metal powder to be rolled, it is preferable to use powder particles activated by heating in a non-oxidizing environment.

(Operation) Here, an emulsion type rolling oil used for continuous tandem rolling of a steel strip will be described as a typical example.

In the present invention, the powder particles of the metal to be rolled whose surface has been activated are, for example, iron, which is in an activated state such that it burns immediately when it is exposed to the atmosphere.

Although the preferred particle size of the metal powder in the present invention varies depending on the chemical composition of the metal and the form of the powder, for example, in the case of steel atomized powder, 90% or more of the particles are composed of particles of 0.5 μm or less. preferable. The reason for this is that as the particle size of the metal powder becomes smaller, the specific surface area becomes larger, the probability of contact with rolling oil increases, and the chemical reaction (degradation reaction of rolling oil) using the metal as a catalyst easily occurs. Therefore, it is desirable that the particle size of the metal powder be as small as possible.

The component of the metal powder used here is mainly composed of the metal to be rolled, and it is more advantageous to contain the impurity element generally contained in such unrolled metal.

Further, in order to promote the deterioration reaction of the rolling oil by the metal powder, it is important to activate the surface of the metal powder.
The surface of the metal powder before activation is often covered with an adsorbate such as water or an organic substance, and the purpose of activation is to remove the adsorbate. The method of activating the metal powder is not particularly limited, but in the case of iron, the method of heating in a non-oxidizing atmosphere or vacuum is particularly advantageous.
To give an example, iron powder should be used in a non-oxidizing atmosphere or in a vacuum of 40
By heating at 0 to 500 ℃ for 10 to 30 minutes, it becomes an activated state that burns immediately in the atmosphere. In this case, the metal powder after completion of activation maintains the initial particle size, but when the heating temperature becomes too high, the metal powders are welded to each other and the particle size becomes large, so that the intended purpose cannot be achieved. It is not preferable.

As a gas that forms a non-oxidizing atmosphere, helium (He), argon (Ar), neon (Ne), xenon (Xe), nitrogen (N ₂ ) etc. that do not cause an oxidation reaction on the metal surface Is preferred. Also, in order to improve the activity of the metal powder, 10% or less of hydrogen (H ₂ ) is used as the above gas.
A reducing gas containing carbon monoxide (CO) or the like can also be used.

The metal powder thus activated needs to be put into rolling oil without being exposed to oxygen. For this purpose, activated metal powder is put into rolling oil under a non-oxidizing atmosphere. The metal powder put in the rolling oil is uniformly dispersed in the rolling oil or the rolling oil emulsion. By this operation, all the metal powder surfaces can be brought into contact with rolling oil.

In the case of tandem rolling of steel in which water-soluble rolling oil is circulated, the abrasion powder generated may be dispersed in the rolling oil emulsion and the iron powder content may exceed 0.1% and reach a maximum of 1.0%. . Therefore, in the method of the present invention, in order to promote the chemical reaction using a metal as a catalyst, it is preferable to add the activated iron powder in an amount larger than the maximum amount of iron actually mixed. This is because if the amount of activated iron powder is small, the chemical reaction with iron as a catalyst will not proceed sufficiently in a short period of time, and it will not be possible to reproduce the usage conditions of the actual equipment.

Further, even in the case of rolling oil for rolling a metal other than steel, it is preferable to add a larger amount of activated metal powder than the amount of metal actually used. This is because, as described above, by using a larger amount than the maximum amount that actually mixes, the usage status of the actual machine can be reproduced in a shorter time.

By the way, in the case of rolling steel, the rolling oil emulsion being circulated is sprayed onto the material being rolled, which has reached 120-160 ° C.
It is constantly exposed to an environment where it is heated and even concentrated. Therefore, the emulsion in which the activated metal powder is added can be brought into conformity with the actual use state only after heating or concentrating by boiling after stirring.

By the way, in the steel tandem rolling mill, if the tandem capacity of the emulsion is about 10 ⁵ liters and the work that generates a large amount of heat is performed, it will take about 8 hours and the emulsion tank capacity of about 2 × 10 ⁵ liters will generate heat. If a relatively small amount of work is performed, about half of the tank capacity will be replenished in about 40 hours. Therefore, the boiling concentration is 60 ~
It is desirable to adjust it to 20%.

Further, the boiling oil-concentrated rolling oil emulsion is returned to the original emulsion amount, stirred, and then activated metal powder is added again, and boiling-concentration is repeated, whereby a more severe use condition can be reproduced.

(Example) As a rolling oil for evaluation, using a rolling oil for a mineral oil mill clean for steel, a rolling oil for a synthetic oil thin product, and a sample prepared under the following four conditions A to D, (a) The general properties of the extracted oil, (b) infrared spectroscopic analysis, (c) emulsifying property, and (d) mill clean property were tested, and the obtained results were compared with the test results of emulsions used in an actual machine for one month or more. .

Condition-A (Example) -Emulsion: 3%, 400 ml-Particle size of iron powder: 0.02 μm (maximum 0.05 μm, specific surface area = 46 m ² / g) -Input amount: 0.4 g (0.1%)-Iron powder activity Aging temperature: 400 ℃ × 30min ・ Non-oxidizing gas: N ₂・ Boiled concentration = 400ml-200ml concentrated (50%) ・ Boiled concentration frequency: 3 times Condition-B (Example) ・ Emulsion: 5%, 400ml・ Iron powder particle size: 0.02μm (maximum 0.05μm, specific surface area = 46m ² / g) ・ Input amount: 0.5g (0.125%) ・ Iron powder activation temperature: 450 ℃ × 15min ・ Non-oxidizing gas: He・ Boiling concentration = 400ml-200ml (50%) ・ Boiling concentration: 2 times Condition-C (Comparative example) ・ Emulsion: 5%, 400ml ・ Iron powder particle size: 0.50μm (max 1.70μm, actual machine) Extraction of abrasion powder during rolling) ・ Input amount: 0.4g (0.1%) ・ Iron powder activation temperature: 200 ℃ × 30min ・ Non-oxidizing gas: N ₂・ Boiling concentration = 400ml-320ml (80%) ・ Boiler concentration times: 2 times Condition-D (Comparative example) ・ D Rujon: 5%, 400ml · iron powder particle size: 0.02 [mu] m (maximum 0.05 .mu.m, specific surface area = 46m ² / g) · input amount: 0.2g (0.05%) · iron powder activation temperature: 450 ℃ × 15min · Non-oxidizing gas: He-Boiling concentration = 400 ml to 200 ml (50%)-Boiling concentration: 1 time Comparative test method i) General properties-Acid value: JIS K 2501 ・ Saponification value: JIS K 2503 ・ Oil Molten iron: The extracted oil component of the rolling oil coolant was subjected to centrifugal separation to remove friction powder, then ashed, the ash was dissolved with hydrochloric acid, and the iron component was measured by an atomic absorption method to obtain oil-melted iron.

ii) Emulsifying property After returning the test emulsion to 400 ml, stir it with a homogenizer for 8000 mpm x 1 min and then leave it for 8 minutes.
Was measured.

ESI: Concentration of lower layer 100 ml / concentration of upper layer 100 ml iii) Mill clean property Extracted oil of rolling oil was used as a test piece (spcc-sd, 100 x 100 x
(0.8 mm) on both sides with 500 mg / m ² and overlap them at 120 ° C
After being left to stand in the constant temperature air bath for 24 hours, it was annealed under the following annealing conditions. The stains on the surface of the annealed test piece were peeled off with a Scotch tape, the scorch tape was attached to a ketone paper, and the reflectance (Y value) of the surface was compared.

[Annealing conditions]

・ Flow gas: Mixed gas of 95% nitrogen and 5% hydrogen ・ Flow rate: 0.1m ³ / h ・ Raising rate: 200 ℃ / h ・ Holding temperature: 700 ℃ ・ Holding time: 1h iv) Iron soap amount of rolling oil after the extraction oil with 0.1mm spacer to infrared spectroscopic analysis, the peak height from the chart 1900cm ^-1 (I _0%) and the peak height of 1600 cm ^-1 with iron soap (I _1%)
Was calculated and applied to the following formula to compare the amounts of iron soap.

Iron soap amount = logI ₀ / logI ₁ The values when fresh oil were = 1.134 and = 0.113.
This is due to naphthenic mineral oil, not iron soap. This value increases as the iron soap increases.

 The experimental results are shown in Table 1.

As shown in the table, the ones prepared under the conditions-A and B (Examples) showed almost the same results as those when used in the actual machine, with respect to changes in the content components of the rolling oil and various performances of the rolling oil. It can be seen that the actual usage situation has been reproduced.

(Effects of the Invention) Thus, according to the present invention, it is possible to reproduce a water-soluble cold rolling oil in a laboratory in a short period of time in almost the same state as the actual state of use, and to stabilize for a long period of time. It has a great effect when used for developing rolling oil.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohisa Ono 1-chome, Mizushima Kawasaki-dori, Kurashiki-shi, Okayama Prefecture (no address) Inside the Mizushima Works, Kawasaki Steel Co., Ltd. (72) Shigeru Kuroda 1 Mizushima-kawasaki-dori, Kurashiki-shi, Okayama Prefecture Chome (No house number) Kawashima Steel Co., Ltd. Mizushima Steel Works (72) Inventor Etsushi Hino Mizushima Kawasaki Dori, Kurashiki City, Okayama Prefecture (No house) Kawasaki Steel Co., Ltd. Mizushima Steel Works (72) Inventor Isamu Oikawa Kanagawa Prefecture 5-12-15 Okada, Samukawa-cho, Koza-gun (72) Inventor Masataka Shirata 2-1-5 Yurigaoka, Ninomiya-cho, Naka-gun, Kanagawa (72) Inventor: Masayoshi Sakakibara 5539 Ohba, Fujisawa-shi, Kanagawa Charmancopo 308 (72) Inventor Mizuho Sano 4185 Ohba, Fujisawa City, Kanagawa Prefecture C-101 (72) Inventor Takashi Ogawa 778-5, Nakajima, Kurashiki City, Okayama Prefecture (56) Reference Document JP-flat 4-218768 (JP, A)

Claims (4)

(57) [Claims] 1. Preparation of a rolled sample for evaluation, characterized in that powder particles of a metal to be rolled whose surface has been activated are introduced into a rolling oil to be evaluated without being exposed to the atmosphere, and then uniformly dispersed. Method. 2. A method for preparing a rolling oil sample for evaluation, which is obtained by heating or boiling and concentrating a rolling oil mixed with powder particles of a metal to be rolled whose surface has been activated. 3. The method for preparing a rolling oil sample for evaluation according to claim 2, wherein the heating or boiling concentration step is repeated. 4. The method for preparing a rolling oil sample for evaluation according to claim 1, 2 or 3, wherein powder particles activated by heating in a non-oxidizing environment are used as the metal powder to be rolled.