JP3175270B2 - Corrosion test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrosion test apparatus for measuring the progress of a corrosion reaction of a metal member in water. In particular, the present invention relates to a corrosion test apparatus capable of measuring the progress of corrosion affected by microbial factors with a relatively small configuration.

[0002]

2. Description of the Related Art As a device for measuring corrosion of metals affected by microbial factors in water, a test piece is immersed in a test water tank (100 liters), and the solution is circulated to measure corrosion potential (current). A corrosion test apparatus as described above is used.

[0003] As another corrosion test apparatus, there is a simple test apparatus for collecting test water in a 1-liter beaker, immersing a test piece under test, and measuring a corrosion potential (current).

[0004]

The former apparatus using a 100-liter test tank is large in scale, increases the equipment cost, and requires a large amount of test water. There is a problem that labor is required.

According to the latter corrosion test apparatus using a 1-liter beaker, heating and stirring can be performed, but there is a problem that the influence of microbial factors on corrosion cannot be sufficiently reflected in changes in potential (current).

That is, the amount of microorganisms in the test water is small relative to the test piece surface, there is no supply of nutrients necessary for growth, and the microflora cannot be maintained in a steady state for batch testing.

There are disadvantages such as

[0008] In order to cope with such a problem, microorganisms preliminarily separated and cultured are artificially applied to the test piece surface, and the amount of attached microorganisms is measured with high sensitivity using a metal-deposited quartz oscillator. Attempts have been made, but practical problems remain.

[0009] The present invention solves the above-mentioned conventional problems and provides a comparison in consideration of the influence of microbial factors for reproducing the progress of a corrosion reaction in water in a field, a laboratory, or a laboratory where metal corrosion is a problem. It is an object of the present invention to provide a small-scale simulation test apparatus.

[0010]

A corrosion test apparatus according to the present invention comprises a test tank with drainage means, a test water supply means for supplying test water to the test tank with drainage means, and an oxygen supply to the test tank with drainage means. Means for replenishing oxygen, electrochemical corrosion measuring means for measuring the corrosion tendency taking into account the microbial factors of the test water in the test tank with drainage means, and a display for receiving and displaying a signal from the measuring means Means.

In the present invention, the above-mentioned test tank includes:
For example, a beaker having a volume of about 1 to 2 liters can be used.

The drainage means provided in the test tank may be, for example, one provided with a drainage port on the surface of the test tank so as to automatically drain the added water, or a drainage pump. There may be.

It is preferable that the drainage means be capable of keeping the water level in the test tank constant so that the effects of microorganisms can be correctly observed.

As the oxygen replenishing means, for example, an air diffuser can be suitably used.

As the display means, a display means for displaying an image on a monitor using a liquid crystal panel or a cathode ray tube is suitable, but a display means for directly viewing the meter portion of an analog potentiometer may be used.

As an electrochemical corrosion measuring means, a test piece (test piece) and a reference electrode are immersed and arranged in a test water, and a potential difference between them or a current flowing between the two is detected. Is preferred. In addition, in addition to a silver-silver chloride electrode, SUS, Pt, Au
And a C (carbon) electrode.

As the test piece, a new piece or a piece to which microorganisms have already adhered is used depending on the purpose of the test.

In order to take into account the influence of microbial factors on corrosion, it is preferable to immerse solids (such as test pieces) to which microorganisms have already adhered or to initially introduce bacteria separated therefrom in the test tank. .

[0019]

In the corrosion test apparatus of the present invention, the corrosion of a metal member (test piece) is measured, for example, as follows.

The test water is supplied to a small volume (1-2 liter) test tank maintained at a constant temperature, and the same amount is discharged. The test piece and the reference electrode are immersed in the tank, and the potential or current between them is changed over time.

As described above, when the test piece is immersed in the test water in the test tank, transfer of bacteria onto the test piece,
Since the growth occurs spontaneously, the change in potential (potential rise as a pre-stage of local corrosion) due to the attachment of microorganisms can be reproduced.

On the metal surface, three steps of formation, destruction, and repair of an oxide film proceed in parallel in time and space. Each reaction involves an electrochemical reaction, and the corrosion state can be estimated from changes in potential and current.

[0023]

Embodiments will be described below with reference to the drawings. FIG. 1 is a front internal configuration diagram showing the configuration of the apparatus of the embodiment,
FIG. 2 is a front view.

The inside of the rectangular casing 10 is the shelf 1
The test tank 16 is divided into three sections by 2 and 14, and a test tank 16 is installed in the middle section. Although only two test tanks 16 are shown in FIG. 1, one or three or more test tanks may be provided. An overflow water drainage port 18 is provided on a side surface of the test tank 16, and overflow water is received on a drainage tray 20 disposed at a lower stage in the casing 10.

A water supply pump 2 is provided in an upper stage in the casing 10.
2, an air pump 24, a scanner 26, a potentiometer 28, and a computer (personal computer) 30 are installed, and a screen 30a of the personal computer 30 is visible from outside the casing 10. Reference numeral 32 in FIG.
Is a timer. This timer 34 is intermittent (for example, 6
It is used when the pumps 22 and 24 are operated at times of ON, 30 minutes OFF, etc.). Reference numeral 34 in FIG. 1 is a viewing window.

The water in the test water container 36 installed on the side of the casing 10 is supplied into the test tank 16 via the pipe 38, the water supply pump 22, and the pipe 40. The air from the air pump 24 is supplied to the air diffuser 44 in the test tank 16 via the pipe 42.

A sample electrode (test piece) 46 and a reference electrode 48 are immersed in the test tank 16, and a potential difference between them is detected by a potentiometer 28 via a scanner 26 and transmitted to a personal computer 30. Sent.

The scanner 26 is for sequentially selecting signals from a plurality of test tanks and sending them to the potentiometer 28. The personal computer 30 accumulates data for each test tank 16 and collects the data. The change of the potential difference over time (for example, day) is displayed on the screen 30a as a graph.

In the lower part of the casing, various switches and a temperature controller in the casing 10 are provided.

The apparatus of this embodiment has the following excellent features as compared with a conventional apparatus using a 100-liter test tank and a beaker test of about 1 liter.

The labor, cost, and the like required for sampling and transporting test water are reduced to about 1/5 as compared with a 100-liter tank. Note that even if the test water is exchanged at a rate of 0.5 liter / day in the 1-liter test tank of this embodiment, 1
15 liters of water is sufficient for the test in a month.

The site required for the test is 1/100 of the 100 liter tank. For example, when a casing having a width of 800, a depth of 832, and a height of 1810 mm is used,
It is possible to install 30 1-liter water tanks. In the case of a 100-liter tank, a site close to 3 m ² is required for each tank.

Since the replenishment, retention, DO replenishment by aeration, mixing in the tank, replenishing water as a nutrient source, and temperature control are performed, potential and current changes due to biological factors can be reproduced. On the other hand, a simple test of only one liter cannot often reproduce the increase and decrease of the potential and the current accompanying the progress of corrosion.

[0034]

As described above, the corrosion test apparatus of the present invention
It has the following excellent effects.

Since the amount of test water used may be small, labor and cost for water collection and transportation are small.

The device configuration is compact and the installation area is small.

Corrosion in consideration of corrosion caused by microbial factors can be measured.

[Brief description of the drawings]

FIG. 1 is an internal front view of an embodiment device.

FIG. 2 is an external front view of the embodiment device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Casing 16 Test tank 20 Drain pan 22 Water supply pump 24 Air pump 26 Scanner 28 Potentiometer 30 Computer 36 Test water container 46 Sample electrode 48 Reference electrode

Claims (1)

(57) [Claims] 1. A test tank with drainage means, a test water supply means for supplying test water to the test tank with drainage means, an oxygen supply means for supplying oxygen to the test tank with drainage means, and the drainage means A corrosion test apparatus comprising: an electrochemical corrosion measuring means for measuring a corrosion tendency in consideration of a microbial factor of a test water in a test tank; and a display means for receiving a signal from the measuring means and displaying the signal.