JPH07109397B2 - Method for measuring iron content in soluble oil - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for measuring iron content in a solvent oil.

As a conventional oil, for example, cold rolling oil such as steel strip improves rolling property of a rolling mill and imparts a simple rust preventive function between processes. The measurement of is an essential control item for quality maintenance from the viewpoint of cleanliness of steel strips and prevention of flaws.

Therefore, the iron content in the rolling oil is measured, and for example, as in JP-A-49-75197, a capacitance measuring electrode composed of one side of a bridge circuit is immersed in a rolling oil flow, and a high frequency carrier wave is applied. A method is disclosed in which the iron content is measured by applying a change in the capacitance when the metal powder in the rolling oil is mixed and using the change as an electric signal.

However, in such a measurement method, the particle size distribution of the iron powder in the oil is non-uniform, so the change in the dielectric constant is not uniform with respect to the change in the amount of iron powder, and the oil content of the iron on the capacitance measuring electrode Since the measurement accuracy is poor due to the change in capacitance due to the adhesion of oil-degraded substances such as
Take out a part of the rolling oil into a flask, heat it to ash, dissolve it with mineral acid such as hydrochloric acid, and dilute it with water to a certain amount, and then measure the iron content in the rolling oil with a base paper absorption spectrometer, for example. It takes about 200 minutes.

However, in continuous cold rolling of steel strip, the rolling time is about 10 minutes on average in the case of 40t coil, and as many as 20 (800t) are rolled with 40t coil during measurement of rolling oil. , For example, if the iron concentration in rolling oil (recycled) has risen above a certain level, the steel strip becomes dirty,
In addition to the abrasion of the roll, iron is attached to the roll, which causes a large defect such as a defective coil in which a flaw is transferred to the steel strip.

Also, when cutting steel, etc., it takes a long time to cut out a part of the cutting oil and similarly measure the iron content in the oil.
This is accompanied by defects such as the occurrence of flaws on the surface of the treated material due to uneven wear of the cutting tool (grinder, etc.), and the cut surface is not smooth.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention has been made in order to surely solve the above-mentioned drawbacks of the prior art, and provides a quick and simple method for measuring iron content in a solvent oil.

Means for Solving the Problems A feature of the present invention is that iron-containing solvel oil is stored and weighed so as not to mix bubbles in a container, and subsequently a magnet is brought close to balance iron in oil with gravity. As described above, the present invention relates to a method for measuring an iron content in a soluble oil, which comprises moving the container to the upper portion of the container and holding it by magnetic force to measure the weight reduction amount in the iron-containing soluble oil.

That is, in the present invention, for example, a part of the soluble oil in use (recycled use) is taken out, stored in a non-magnetic container, and then weighed by a balance or the like, and the magnet is placed at a fixed distance above the container or The weight change is measured while the iron powder is moved close to the horizontal direction and all the iron powder is moved to the upper side of the container (that is, the weightless state), and both the balance and the magnet are commercially available.

As for the strength of the magnet and the weighing performance, the iron concentration is 10 ppm.
In the case of the above 30 cc of soluble oil, the magnetic force may be 1000 gauss or more, the minimum sensitivity of weighing may be 1 mg or more, the magnet may be an electromagnet in addition to the permanent magnet, and the weighing may be replaced by a force sensor such as a pressure sensor other than the balance. Also has the same effect.

As the soluble oil for measuring the iron content in this way, cold rolling oil for steel strip, cutting oil for cutting, press oil for press working, release oil for mold release, lubricating oil such as engine oil, etc. , Dispersed oils such as molding oils for processing and molding, and emulsified oils.

The container for storing the solvel oil may be any material that has a property of transmitting magnetic force (magnetic permeability). For example, non-magnetic metal / alloy (Al, austenitic stainless steel, etc.),
There are glass, ceramics, plastics, etc. And
The shape of the container is preferably such that the upper part of the container intersects perpendicularly to the magnetic field lines, for example, in the shape of a rectangular parallelepiped (in each case) in terms of stability when the weighing machine is set and floatability of iron powder when a magnetic force is applied. The shape is preferable, but a cylindrical container may be used if a dedicated pedestal is provided. When the lipophilicity of the inner surface of the container is high (for example, the unevenness of the inner surface is large), the iron powder-adhering oil adheres to the inner wall of the container, making it difficult to float. Therefore, the lipophilicity of the inner surface of the container is preferably low. It is preferable that air bubbles are not mixed in to store iron-containing soluble oil. Therefore, at least the upper part of the container (for example, the upper surface of the container, the upper part of the side surface of the container, etc.) should be transparent or translucent to monitor the mixed condition of the air bubbles. It is desirable to be a material.

Next, an example of the present invention will be described with reference to the drawings.

In FIG. 1, iron-containing solvable oil 3 is stored in a container 2 made of a non-magnetic material such as glass in a weighing device 1 (to prevent bubbles from being mixed) and weighed. Next, the iron powder 5 in the iron-containing solvent oil 3 is moved to the upper part of the container 2 by magnetic force and held by the magnetic force by approaching the magnet 4, and the iron powder 5 becomes weightless, and the weight at this time is weighed.

Therefore, as described above, the weighed value after the iron-containing soluble oil 3 is filled in the container 2 and the magnet 4 as described above are brought close to each other, and the iron powder 5 in the iron-containing soluble oil 3 in the container 2 is in a weightless state. The difference between the weighed values at this time is the amount of iron powder 5.

Examples Next, examples of the present invention will be given together with comparative examples.

Example 1 Using a continuous cold rolling mill for steel strips, rolling oil during rolling of steel strips (rolling oil in circulation use) was bubbled into a glass container with a cap having a volume of 100 ml (outer dimensions 100 × 52 × 20 mm). It was stored so that it would not get caught, the weight was measured with a balance, and then the iron concentration was measured as 30 ppm from the weight loss when a plate-shaped permanent magnet (100 x 100 x 30 mm) with a magnetic force of 1000 Gauss was fixed at a distance of 20 mm above. did. The predetermined time was 15 minutes in consideration of rolling oil storage, setting on a balance, and the like.

When the rolling oil at this time was analyzed, it was found to be mineral oil 50%, synthetic ester and fat 40%, fatty acid 3%, emulsifier 4%, antioxidant 1%, extreme pressure agent 2%.

Comparative Example 1 100 ml of the rolling oil in the rolling oil under the same conditions as in Example 1 was taken out (combined with Example 1 and 200 ml was extracted) and stored in a container at 120 ° C.
After heating on a hot plate for 90 minutes to remove water, heat ash in an electric furnace at 800 ° C for 30 minutes, cool at room temperature for 30 minutes, and then cool to 18%.
After adding 30 ml of HCl, heating and dissolving on a hot plate for 20 minutes, the mixture was cooled, the volume was increased to a 100 ml measuring flask, and the concentration of iron was determined to be 30 ppm by atomic absorption spectrometry. The time required was 214 minutes, including rolling oil storage, heating ashing, acid addition heating dissolution, measuring up, and atomic absorption measurement.

When the rolling oil at this time was analyzed, it was found to be mineral oil 50%, synthetic ester and fat 40%, fatty acid 3%, emulsifier 4%, antioxidant 1%, extreme pressure agent 2%.

Example 2 While supplying cutting oil to the surface of a steel material with a grinder, the cutting oil is stored in a glass container with a cap having a volume of 100 ml (outer dimension 100 × 52 × 20 mm) so as not to entrap air bubbles, The force that acts on the magnet when fixed at a position 20 mm above the magnet (100 × 100 × 50 mm) with a magnetic force of 2000 Gauss connected to the pressure sensor through the prism of a non-magnetic material (100 × 100 × 200 mm made of polypropylene). Measure the change with a pressure sensor,
The iron concentration was measured as 50 ppm. The time required is cutting oil storage,
It took 14 minutes, including the setting to the measurement position. When the cutting oil at this time was analyzed, mineral oil 80%, surfactant 9
%, Fatty acids 5%, amines 4%, antibacterial and antifungal agents 2%.

Comparative Example 2 Under the same conditions as in Example 2, 100 ml of cutting oil during cutting was taken out (combined with the amount of Example 2 and extracted in 200 ml) and stored in a container, and
After heating on a hot plate for 90 minutes to remove water, 800 ℃
Heat ash in an electric furnace for 30 minutes, cool at room temperature for 30 minutes, then
Add 30 ml of% HCl, heat and dissolve on a hot plate for 20 minutes, cool, and make up to a 100 ml volumetric flask. Measure the iron concentration to be 50 ppm by atomic absorption spectrometry. It took a long time of 210 minutes, including ashing, acid addition heating dissolution, measuring up, and atomic absorption measurement.

Analyzing the cutting oil at this time, mineral oil 80%, surfactant 9%, fatty acid 5%, amines 4%, antibacterial and antibacterial agent 2
%Met.

EFFECTS OF THE INVENTION According to the present invention, the measurement of the iron content in the soluble oil can be significantly shortened, and the deterioration of the quality of the treated material due to the increase of the iron content in the oil can be prevented.

In addition, the yield of treated material can be improved.

Further, roll reshuffling due to flaw generation and wear of the rolling roll can be extended, and the roll unit can be improved.

Furthermore, it is possible to reduce wear of a cutting machine tool such as a grinder, reduce costs, and reduce defects in the treated material to improve quality.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of the present invention. 1 ... Weighing machine, 2 ... Container, 3 ... Soluble oil, 4 ...
Magnet, 5 ... iron powder.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Haruo Koganemori 5-3 Tokai-cho, Tokai City, Aichi Pref. Nippon Steel Co., Ltd. Inside the Nagoya Works (56) References JP-A-49-50995 (JP, A) )

Claims (1)

[Claims] 1. An iron-containing solvel oil is stored and weighed in a container so as not to mix air bubbles, and then a magnet is brought close to the iron, and iron in the oil is moved to the upper part of the container so as to balance with gravity and retained by magnetic force. A method for measuring iron content in a soluble oil, comprising measuring the amount of weight loss in the iron-containing soluble oil.