KR20200036387A - Soil environment complex corrosion accelerating test apparatus - Google Patents

Abstract

The present invention relates to a complex corrosion acceleration test apparatus in a soil environment, which comprises: a chamber (10) of which the inside is closed; a basket (80) which is arranged on the inside of the chamber (10) and in which soil (83) is contained such that a test piece (m) can be buried therein; a salt water spray unit (20) which sprays a solution containing salt into the chamber (10) in order to control the humidity and the salt concentration in the chamber (10); a heating unit (30) which controls the temperature in the chamber (10); a detection unit (40) which detects the humidity, the temperature, and the salt concentration in the chamber (10); and a control unit (50) which controls the operation of the salt water spray unit (20) and the heating unit (30) in accordance with the detection result of the detection unit (40) in order to control the humidity, the temperature, and the salt concentration in the chamber (10). Therefore, a complex corrosion test of a test piece such as a grounding material can be performed in a soil environment. In addition, the actual soil environment can be imitated to provide an acceleration test result with reliability.

Description

SOIL ENVIRONMENT COMPLEX CORROSION ACCELERATING TEST APPARATUS}

The present invention relates to a soil environment complex corrosion acceleration testing apparatus, and more specifically, a soil environment complex corrosion providing a soil environment capable of controlling humidity, temperature and salt concentration so as to test corrosion resistance of a ground material embedded in the soil. It relates to an acceleration test apparatus.

Corrosion is a phenomenon that is degraded by a chemical reaction or an electrochemical reaction with various substances in its environment. As a result, destruction of parts and structures occurs or durability is reduced, resulting in economic loss.

In Korea, economic losses due to corrosion amount to about 3% of GNP. Since corrosion occurs in all production and consumption fields, the problems of industrial and social stability are very large. The development of technology to prevent this is very important, and many countries are making great efforts to reduce the economic loss caused by corrosion.

In general, various electric facilities (electric poles, street lights, switchboards) are installed with a ground electrode in the soil to secure electrical stability from lightning strikes and surges and to prevent various accidents caused by short circuits. For example, equipment and neutral wires installed on poles, such as lightning arresters and transformers, are constructed for earth grounding, so the grounding construction method using grounding materials such as a grounding rod or shim rod is applied.

The grounding facility provides a reference potential during normal operation of the power facility, and in the event of failure and abnormal operation, the fault current and the abnormal current are rapidly discharged to the ground to suppress a rise in line potential.

The life of the grounding material embedded in the soil is determined by corrosion resistance. Corrosion is widespread in all industries and many preventive measures are used, but in the case of distribution grounding materials, it is buried in the soil, so it exhibits characteristics different from those of general atmospheric or marine corrosion.

In the soil environment, corrosion occurs on the same principle as corrosion occurring in aqueous solution conditions, but in the soil, it has the characteristic that the fluidity of chemicals is very small, unlike the aqueous solution environment.

In particular, important factors affecting soil corrosion are aeration, water content, resistivity, pH, and corrosive ion concentrations.

In addition, it takes a lot of time to evaluate corrosion resistance in an actual outdoor soil environment. Therefore, it is necessary to design an accelerated test method that takes a short time to develop a new product or to evaluate it among several existing materials, and exhibits corrosion characteristics similar to those of aged deterioration products in an actual outdoor soil environment.

Patent Document 1: Published Patent Publication No. 2011-0073622 (published on June 30, 2011)

An object of the present invention is to provide a soil environment capable of controlling humidity, temperature, and salt concentration so as to test corrosion resistance of a ground material buried in the soil, and accelerate corrosion reaction to accelerate corrosion reaction to evaluate corrosion resistance in a short time. It is to provide an acceleration test device.

According to the features of the present invention for achieving the above object, the present invention is disposed inside the sealed chamber and the chamber, the soil is supported, and a basket capable of embedding the test piece and salt is added inside the chamber Brine spray unit to adjust the humidity and salt concentration inside the chamber by spraying the solution, a heating unit to control the temperature inside the chamber, and a sensing unit and the sensing unit to detect humidity, temperature and salt concentration inside the chamber It includes a control unit for controlling the operation of the salt spray unit and the heating unit according to the detection result to adjust the humidity, temperature and salt concentration in the chamber.

The chamber is mounted with the basket and separates the internal space of the chamber into an upper space and a lower space, and air for supplying dry air to the upper space of the chamber and a pedestal formed with a through hole communicating the upper space and the lower space. It includes a supply pipe and a drain pipe capable of exhausting salt water generated during the test to the outside, and an exhaust pipe for exhausting internal air generated during the test to the outside.

The basket is formed with an open top, and a plurality of perforations for drainage are formed on the bottom surface.

The basket is provided with a nonwoven fabric to prevent the soil from being discharged to the outside through the perforated portion.

The basket is made of synthetic resin material.

It may include a sensor for sensing the environment of the soil carried in the basket.

The sensor may be an electrode sensor installed in the soil to measure humidity, specific resistance and temperature of the soil.

The electrode sensor may include a power terminal, a data terminal, and a ground terminal.

It may include a monitoring unit for storing and real-time display of the humidity, specific resistance and temperature data of the soil sensed by the sensor.

A plurality of baskets may be disposed inside the chamber.

The test piece may be a grounding material.

The present invention embeds the test piece in the soil in the basket, and after placing the basket in the chamber, performs a corrosion evaluation test of the test specimen while maintaining a constant humidity, temperature and salt concentration in the chamber. In addition, the basket has a perforated portion formed so that water can be drained, a nonwoven fabric is disposed, and the soil is supported on the upper portion, so that the environment in the soil supported in the basket is kept constant in response to the conditions in the chamber.

Accordingly, the present invention can perform a complex corrosion test of a test piece such as a grounding material in a soil environment, and can simulate a real soil environment, thereby providing a reliable accelerated test result in a short time.

1 is a conceptual view showing a soil environment complex corrosion acceleration test apparatus according to an embodiment of the present invention.
Figure 2 is a cross-sectional view showing the internal appearance of the basket according to an embodiment of the present invention.
3 is a view showing an example of a sensor according to an embodiment of the present invention.
Figure 4 is a photograph showing a state in which a ground enclosed test piece is buried in a specific location in the soil supported in the basket as an embodiment of the present invention.
5 is a photograph showing the state of the test piece enclosed in the basket after placing the basket of FIG. 4 in the chamber and evaluating the corrosion for 1 month.
6 is a photograph showing a state in which the soil on the ground enclosed test specimen of FIG. 5 is removed with distilled water.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Soil environment composite corrosion acceleration test apparatus (hereinafter referred to as 'composite corrosion acceleration test apparatus') of the present invention, as shown in Figure 1, the chamber 10 and the chamber where the humidity, temperature and salt concentration are controlled constantly ( 10) It is disposed inside and the soil is supported, and includes a basket 80 capable of embedding the test piece (m).

The chamber 10 is formed with internal spaces 12a and 12b in which test pieces and test-related accessories can be arranged, and the internal spaces 12a and 12b have a closed structure. The chamber 10 may be made of glass-reinforced plastic, polypropylene, or PVC material to resist salt. In addition, the chamber 10 may include an insulating material on the inner wall to prevent changes in the internal environmental conditions. The chamber 10 includes a cover 11 for opening and closing the internal spaces 12a and 12b, and the cover 11 is provided with a gasket so that the chamber 10 has a closed structure in a state where the cover 11 is closed. Can be.

The chamber 10 includes a salt spray part 20, a heating part 30, a sensing part 40, and a control part 50 for controlling humidity, temperature and salt concentration.

The salt spray unit 20 controls the humidity and salt concentration inside the chamber 10 by spraying a solution in which the salt is added inside the chamber 10. The salt spray unit 20 may adopt a male wing sprayer shape that moves back and forth to generate a fan-shaped mist spray pattern.

It includes a salt water reservoir 21 for supplying the salt water to the salt spray unit 20. A stirrer 22 is installed in the brine reservoir 21 to prevent aggregation of the brine in the brine reservoir 21. The stirrer 22 may be a stirrer that injects air into the brine. An auxiliary brine reservoir 23 for supplying brine to the brine reservoir 21 is included. The piping connecting the brine reservoir 21 and the auxiliary brine reservoir 23 is provided with a control valve 24 to control the amount of brine supplied to the brine reservoir 21.

It includes a water storage tank 25 for supplying water to the salt spray unit (20). The water supplied from the water storage tank 25 and the brine supplied from the brine reservoir 21 are sprayed to the inner space 12a of the chamber 10 through the salt spray part 20. The salt spray unit 20 may spray salt water in a range of 5 to 10 Ltrs / m 2 per hour.

The heating unit 30 controls the temperature inside the chamber 10. The heating unit 30 may include a heater pipe 31 disposed in the interior space 12b of the chamber 10 and a heater 32 for heating the heater pipe 31.

The sensing unit 40 detects humidity, temperature and salt concentration inside the chamber 10. The result detected by the detection unit 40 is transmitted to the control unit 50. The control unit 50 may control the operation of the salt spray unit 20 and the heating unit 30 according to the detection result of the detection unit 40 to adjust the humidity, temperature, and salt concentration inside the chamber 10. For example, the control unit 50 allows the humidity, temperature, and salt concentration inside the chamber 10 to be kept constant under set conditions.

The chamber 10 includes a pedestal 60 for separating the inner spaces 12a and 12b into an upper space 12a and a lower space 12b. The basket 80 is mounted on the pedestal 60. The pedestal 60 is formed with a through hole 61 communicating the upper space 12a and the lower space 12b. The pedestal 60 may be made of an aluminum frame to support the soil-supported basket 80 at a certain height.

The chamber 10 is connected to an air supply pipe 70 for supplying dry air to the upper space 12a of the chamber 10. An air compressor 71 and a filter 72 are installed in the air supply pipe 70 to continuously supply dry air free of impurities to the upper space 12a. An air circulation pipe 73 capable of circulating air through the air supply pipe 70 is connected to the lower space 12b.

The chamber 10 is provided with a drain pipe 74 capable of draining water or brine generated during corrosion test to the outside. The drain pipe 74 is connected to the bottom surface of the chamber 10. The chamber 10 includes an exhaust pipe 75 for exhausting internal air generated during the corrosion test to the outside. The exhaust pipe 75 serves to adjust the air pressure so that overflow does not occur due to the internal pressure of the chamber 10.

The basket 80 is to allow the test piece to be buried because the soil is supported. The test piece (m) is a grounding material. Depending on the test conditions of the test piece (m), a plurality of baskets 80 may be disposed inside the chamber 10.

2, the basket 80 is formed in a hexahedral shape with an open top, and a plurality of perforations 81 for drainage of salt water or water is formed on the bottom surface. The perforated portion 81 is uniformly formed at regular intervals on the bottom surface of the basket 80 to allow uniform water or brine drainage.

The basket 80 is provided with a nonwoven fabric 85 to prevent the soil from flowing out through the perforated portion 81. In addition to the non-woven fabric 85, various materials can be installed in the basket 80 as long as it prevents the soil from leaking through the perforated portion 81 and drains the brine.

The size of the basket 80 can be manufactured in various ways depending on the size and characteristics of the test piece (m). For example, in order to test the grounding material having a length of 1 m, a basket having a width of 1.2 m, a length of 0.4 m, a height of 0.2 m, and a thickness of 10 mm can be manufactured and punched at regular intervals on the bottom surface to form a punched portion. The basket 80 may be made of a synthetic resin material (eg, polypropylene) that does not corrode in the environment of temperature, humidity and salt.

A non-woven fabric 85 is installed in the basket 80 and the soil 83 is supported thereon.

Soil 83 may use custom sand standard sand for standardized testing, and the size and characteristics of soil particles may vary depending on the actual soil environment to be simulated.

A sensor 90 for sensing the environment of the soil carried in the basket 80 is included. The sensor 90 is installed to be inserted into the soil 83 to monitor whether the environment in the soil 83 supported on the basket 80 is maintained constant. The sensor 90 is an electrode sensor capable of measuring the humidity, specific resistance and temperature of the soil.

As illustrated in FIG. 3, the electrode sensor 90 includes a power terminal 91, a data terminal 92, and a ground terminal 93 to measure soil temperature, moisture, and soil conductivity. The soil resistivity can be calculated by measuring the soil conductivity. The resistivity of the soil is correlated with the humidity, and the corrosion resistance of the test piece can be evaluated by measuring the resistivity of the soil.

Table 1 shows the specifications of the electrode sensor.

Item Sensor specifications Temperature moisture EC (Soil Conductivity) Measuring range -40 ~ 60 ℃ Dielectric constant (εα)
1 (air) to 80 (moisture) 0 ~ 23dS / m Precision ± 1 ℃ ± 15%
(40 ~ 80 VWC) ± 10%
(0 ~ 7dS / m) Resolution ± 0.1 ℃ 0.08%
(0 ~ 50 VWC) 0.01 dS / m 0.05 dS / m
(0 ~ 7dS / m) (7 ~ 23dS / m)

As shown in Table 1, the temperature measurement range of the sensor is -40 to 60 ° C, the moisture measurement range is the dielectric constant 1 to 80, and the soil conductivity measurement range is 0 to 23 dS / m.

As shown in FIG. 2, a pH meter 95 for measuring the pH of the soil supported on the basket 80 may be further included. In addition, it may include a monitoring unit 97 that stores and displays the humidity, specific resistance and temperature data of the soil sensed by the sensor 90 in real time.

Table 2 shows the pH of the soil supported in the basket at the same height.

(Unit: pH) 4.7 4.5 4.5 4.4 4.7 4.9 4.7 4.9 4.8 5.0 4.5 4.8 4.6 4.8 4.5 4.8 5.0 4.7 4.9 4.8 4.7 4.4 4.6 4.9 5.0 4.9 4.9 4.8 4.9 4.7

Table 3 measures the relative moisture and pH distribution by basket height.

Depth (cm) Relative moisture (%) pH surface 2.0 8.4 2 12.0 7.3 4 20.4 5.5 6 36.0 5.5 8 41.2 4.9 10 41.6 5.0 12 (bottom side) 41.6 4.9

According to Table 2 and Table 3, it is confirmed that the pH at the same height shows similar values, and the water content and pH value are maintained constant at a specific depth or more.

Hereinafter, the operation of the present invention will be described.

The present invention, as shown in Figure 2, to place the non-woven fabric 85 in the basket 80 is formed with a perforated portion 81 so that the water is drained on the bottom surface, and supports the soil on the top, soil (83) The test piece (m) is buried.

As shown in FIG. 1, the basket 80 in which the test piece m is embedded is placed in the chamber 10 in which the humidity, temperature and salt concentration are constantly controlled, and the humidity, temperature and salt concentration in the chamber 10 are maintained. The corrosion evaluation test of the test piece (m) is performed while keeping it constant.

During the corrosion evaluation test, the humidity, temperature and salt concentration inside the chamber 10 may be changed according to a specific cycle. Humidity and salt concentration are adjusted by spraying a solution in which salt is added inside the chamber 10 from the salt spray unit 20, and the temperature inside the chamber 10 is controlled by operating the heating unit 30.

In addition, in the corrosion evaluation test process, the humidity can be adjusted by supplying dry air into the chamber 10, and the internal pressure is controlled by exhausting air through the exhaust pipe 75.

The brine sprayed into the chamber 10 is supplied to the soil 83 in the basket 80 and maintains the pH and humidity of the soil 83 constant. Water from the brine supplied to the soil 83 passes through the nonwoven fabric and is discharged to the outside of the basket 80 through the perforated portion 81. Water discharged to the outside of the basket 80 is discharged to the lower space 12b in the chamber 10 through the through hole 61 of the pedestal 60, and then discharged to the outside through the drain pipe 74 of the bottom surface. .

At this time, the humidity, temperature, and salt concentration inside the chamber 10 are detected by the detection unit 40, and the control unit 50 receiving the results detected by the detection unit 40 meets the set conditions, and the interior of the chamber 10 The humidity, temperature and salt concentration are kept constant.

Then, the sensor 90 installed in the soil 83 of the basket 80 measures humidity, specific resistance and temperature of the soil 83 to monitor whether the environment in the soil 83 is kept constant. Since the monitored results can be checked in real time in the monitoring unit 97, sufficient reliability can be secured in predicting the actual soil corrosion reaction. In addition, in the corrosion evaluation test process, the humidity, temperature, and salt concentration inside the chamber 10 can be changed according to a specific cycle to accelerate corrosion reaction, thereby evaluating corrosion resistance in a short time.

In order to guarantee the effectiveness of the present invention, a complex corrosion test of a grounded copper (grounding material) test piece embedded in the ground was conducted.

As shown in Fig. 4, a ground enclosed test piece was prepared, embedded in a specific location in the soil supported by the basket, and placed in a chamber to perform a composite corrosion acceleration test. A sensor and a pH meter were installed on the soil supported in the basket.

The test salt solution was prepared as follows.

It is prepared by dissolving sodium chloride in a range of 45 to 55 g / L. A salt solution is prepared by dissolving 9-11 g / L of sodium sulfate in this solution. As a result of the preparation, the density was measured using a hydrometer and it was confirmed that it was in the range of 1.030 to 1.040 at 25 ° C. The temperature inside the chamber is maintained at 48-52 ° C. The temperature of the salt water container in which the test salt solution is stored is also maintained at 48 to 52 ° C. Using a real-time monitoring unit, it was confirmed that the soil pH, conductivity (specific resistance), and temperature values were kept constant.

Figure 5 is a state of the ground-enclosed test piece after the 1 month test, Figure 6 is a state in which the soil on the ground-enclosed test piece is cleanly removed with distilled water.

As shown in Figure 6, it can be seen that the CuO corrosion product is formed on the surface of the ground-closed test piece. This is the same property as the corrosion properties seen in soil. Through this, it can be confirmed that the complex corrosion test simulating the soil environment can be performed through the complex corrosion acceleration test apparatus of the present invention.

From the above test results, the composite corrosion accelerator of the present invention can accelerate the corrosion reaction to evaluate the corrosion resistance of the metal test piece in a short time, and to ensure sufficient reliability in predicting the actual soil corrosion reaction, the soil environment It can be applied as a standard test method that reflects as it is.

The present invention described above can be applied to the evaluation of corrosion-resistant materials used in soil, and can also be applied to corrosion evaluation of various materials other than metal.

The present invention has been described with the best embodiments in the drawings and specifications. Here, although specific terms have been used, they are used for the purpose of describing the present invention only, and are not used to limit the scope of the present invention as defined in the claims or the claims. Therefore, the present invention will be understood by those of ordinary skill in the art that various modifications and other equivalent embodiments are possible. Therefore, the true technical scope of the present invention should be defined by the technical spirit of the appended claims.

1: Complex corrosion acceleration test device 10: Chamber
11: Cover 12a: Upper space
12b: lower space 20: salt spray
21: brine 22: agitator
23: auxiliary salt reservoir 24: control valve
25: water storage tank 30: heating unit
31: heater pipe 32: heater
40: detection unit 50: control unit
60: stand 70: air supply pipe
71: air compressor 72: filter
73: air circulation pipe 74: drain pipe
75: exhaust pipe 80: basket
81: punched portion 83: soil
85: non-woven fabric 90: sensor (electrode sensor)
91: power terminal 92: data terminal
93: ground terminal 95: pH meter
97: monitoring unit

Claims (15)

A chamber sealed inside;
A basket which is disposed inside the chamber and on which soil is supported to embed test pieces;
A salt spray unit for adjusting the humidity and salt concentration inside the chamber by spraying a solution with salt added inside the chamber;
A heating unit that controls the temperature inside the chamber;
A sensing unit for sensing humidity, temperature and salt concentration in the chamber; And
A control unit controlling the humidity, temperature and salt concentration in the chamber by controlling the operation of the salt spray unit and the heating unit according to the detection result of the detection unit;
Composite corrosion acceleration test apparatus comprising a. The method according to claim 1,
The chamber
A bracket on which the basket is mounted, the inner space of the chamber is divided into an upper space and a lower space, and a through hole communicating with the upper space and the lower space is formed;
An air supply pipe for supplying dry air to the upper space of the chamber;
A drain pipe capable of exhausting the salt water generated during the test to the outside; And
An exhaust pipe for exhausting internal air generated during the test to the outside;
Composite corrosion acceleration test apparatus comprising a. The method according to claim 1,
The basket is formed in a shape with an open top, and a multi-corrosion acceleration testing device characterized in that a plurality of perforations for drainage are formed on the bottom surface. The method according to claim 3,
The basket is a composite corrosion acceleration test apparatus characterized in that a nonwoven fabric is installed to prevent the soil from being discharged to the outside through the perforated portion. The method according to claim 1,
The basket is a composite corrosion acceleration test device, characterized in that made of a synthetic resin material. The method according to claim 1,
Complex corrosion acceleration test device comprising a sensor for sensing the environment of the soil carried in the basket. The method according to claim 6,
The sensor is installed in the soil, the complex corrosion acceleration test apparatus characterized in that the electrode sensor for measuring the humidity, specific resistance and temperature of the soil. The method according to claim 7,
The electrode sensor is a complex corrosion acceleration test apparatus comprising a power terminal, a data terminal and a ground terminal. The method according to claim 6,
And a monitoring unit for storing and real-time display of humidity, specific resistance and temperature data of the soil sensed by the sensor. The method according to claim 1,
The basket is a composite corrosion acceleration test apparatus, characterized in that a plurality of disposed inside the chamber. The method according to claim 1,
The test piece is a composite corrosion acceleration test device, characterized in that the ground material. A chamber in which humidity, temperature and salt concentration are constantly controlled;
A basket which is disposed inside the chamber and on which soil is supported to embed test pieces;
A sensor for sensing the environment of the soil; And
A monitoring unit that displays the results sensed by the sensor in real time;
Composite corrosion acceleration test apparatus comprising a. The method according to claim 12,
The basket is a composite corrosion acceleration test device characterized in that the upper portion is open and a perforated portion is formed on the bottom surface. The method according to claim 13,
A composite corrosion acceleration test apparatus characterized in that a nonwoven fabric is installed in the basket to prevent the soil from being discharged to the outside through the perforated portion. The method according to claim 12,
The sensor is installed in the soil, the complex corrosion acceleration testing device characterized in that for measuring the humidity, specific resistance and temperature of the soil.

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