JPH078756U - Corrosion test equipment - Google Patents

Abstract

(57) [Summary] [Purpose] It is an object of the present invention to provide an optimum corrosion test device for simulating the corrosion state of the actual seawater piping and the sealed portion of the ship and grasping the corrosion state of the actual structure. [Structure] One or more test tanks, one or more preliminary tanks for supplying a test solution to the test tank and receiving the solution of the test tank, and a rotary drum capable of mounting a test material in the test tank And a corrosion test apparatus comprising liquid level adjusting means between the test tank and the spare tank, and a corrosion test apparatus additionally having heating means, gas discharging means, gas bubbling means, and temperature and humidity monitoring means. Is.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a corrosion test device that can be applied to accelerated corrosion tests such as corrosion conditions of steel materials in seawater pipes and corrosion conditions of sealed parts of ships, as well as corrosion resistance evaluation and coating material corrosion resistance evaluation.

[0002]

[Prior art]

 In general, seawater remains in the seawater pipes and sealed parts of ships, and in high-temperature areas, it is once immersed in seawater and then severely corroded by dew condensation water. Although there are few means to accurately grasp and evaluate the corrosion condition in these parts, automobile companies have a dry-wet repeated test method called cycle test developed by them.

[0003]

[Problems to be solved by the device]

 However, these test methods evaluate the perforation resistance of zinc-based plated steel sheets, and the purpose is to evaluate the sacrificial corrosion resistance of zinc-based plating or the surface treatment on zinc-based plating. It does not evaluate the corrosion resistance of the steel itself, but evaluates the surface treatment on the steel, and as mentioned above, there was no equipment for testing the corrosion resistance of the steel itself in harsh environments.

An object of the present invention is to provide a corrosion test apparatus that solves the above problems.

[0005]

[Means for Solving the Problems]

 The present invention comprises one or more test tanks, one or more preliminary tanks for supplying and receiving a test liquid to and from the test tanks, and a rotating drum for mounting the test material provided in the test tanks. And a liquid level adjusting means between the test tank and the spare tank, and in the corrosion testing apparatus, a heating means, a gas discharging means, a gas bubbling means, a temperature And the humidity monitoring means are added to the above-mentioned corrosion test apparatus. Further, by making the rotary drum movable up and down, it is possible to use one test tank and omit the preliminary tank.

[0006]

[Work]

 According to the present invention, one or more test tanks, one or more preliminary tanks for supplying and receiving a test liquid to and from the test tanks, and a test material for mounting the test material provided in the test tanks are provided. A rotating drum and liquid level adjusting means between the test tank and the auxiliary tank are provided, and heating means, gas discharging means, gas bubbling means, temperature and humidity monitoring means are provided in the test tank and the auxiliary tank. By adding the test tank, the test conditions in the test tank can be changed quickly by adjusting the liquid level with the preliminary tank, and the test can be performed efficiently by using multiple test tanks. It is possible to perform tests at the same time. Also, by making the rotary drum movable up and down, two types of corrosion tests can be performed in the test solution and in the atmosphere in the same tank.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings and tables. [Example 1] As Example 1 of the device of the present invention, Fig. 1 shows an outline of the device composed of two test tanks and one preliminary tank.

As shown in the figure, the apparatus is composed of two test tanks 1 and 2 and one preliminary tank 14, each tank is connected by a pipe P, and an aqueous solution heating unit is provided under each tank. A heater 5, a gas bubbling pipe 7, and an aqueous solution temperature sensor 6 are installed, and a gas temperature sensor 8 and a humidity sensor 9 and a gas discharge valve 10 are installed above each tank. There is.

In addition, each test tank is provided with a rotary drum 3 which is rotated by a motor 11 of variable speed and high torque, and a test material 4 is attached around the rotary drum 3, and by the rotation of the rotary drum 3, It is designed to be repeatedly exposed to artificial seawater 15 and atmosphere 16 in test tanks 1 and 2. The artificial seawater 15 and the atmosphere 16 in the test tanks 1 and 2 and the preliminary tank 14 are controlled by a controller such as a liquid level gauge (not shown) attached to each tank.

First, the test material 4 is attached around the rotary drums 3 of the test tanks 1 and 2, the artificial seawater 15 is mixed in the preliminary tank 14, and the temperature is raised to a predetermined temperature by the heater 5 while bubbling air. Then, the artificial seawater 15 is put into the test tank 1 by the chemical pump 12. In the test tank 1, the test temperature is controlled by the heater 5 and the temperature sensor 6 in the aqueous solution, and air is sent and bubbled through the gas bubbling pipe 7. The gas discharge valve 10 is slightly opened so that the air pressure in the test tank 1 does not rise. Next, the test of the test tank 1 is started by applying a predetermined rotation speed to the rotary drum 3 by the variable speed / high torque motor 11, and the test tank 2 can also be started by the same operation.

When the test tanks 1 and 2 are tested at the same cycle and at the same temperature, the artificial seawater 15 may be moved directly from the test tanks 1 to 2 or the test tanks 2 to 1 to adjust the sea level. Can be controlled by a liquid level gauge (not shown), and the temperature and humidity in the atmosphere 16 can be confirmed by the temperature sensor 8 and the humidity sensor 9. However, if tests with different cycles are performed in test tanks 1 and 2, the seawater capacity of reserve tank 14 should be increased, and in the case of tests in the atmosphere with 100% humidity, artificial seawater 15 should be used for each test. You can return it from the tank to the spare tank.

When the test is conducted in an atmosphere gas such as an inert gas, the inert gas or the like may be fed into the test tanks 1 and 2. By combining with the preliminary tank 14, the test tanks 1 and 2 can be tested under different test conditions. Furthermore, when conducting a test such as seawater piping that is greatly affected by the flow velocity, it is sufficient to increase the rotation speed of the variable speed / high torque motor and give a large flow velocity to the test piece.

By using a plurality of test tanks and a reserve tank required for them or a reserve tank with a large capacity, a cycle test in seawater 15 and 100% humidity in atmosphere 16 or a cycle using an inert gas, etc. Tests are possible, and it becomes possible to simulate the corrosion conditions of actual seawater pipes and the sealed parts of ships, and to understand the corrosion conditions of actual structures. Next, a test simulating a ballast tank of a ship was conducted by using the test tanks 1 and 2 shown in FIG.

Five cycles of repeated exposure to artificial seawater 15 at a temperature of 40 ° C. for 1 week and to atmospheric air 16 at a temperature of 40 ° C. at a humidity of 100% for 5 cycles were carried out for 70 days. The test tanks 1 and 2 had the same cycle, and the test tank 2 was started from the cycle of being exposed to the artificial seawater 15 with a delay of 1 week. There are seven types of test materials used: ordinary steel, 1% Cr steel, 2% Cr steel, 3% Cr steel, 6% Cr steel, 9% Cr steel and 13% Cr steel. The rust composition, amount of corrosion and pitting depth were investigated. The results are shown below.

Table 1 shows the rust composition analysis of the test material by X-ray diffraction. For both the 1 to 13% Cr steel and the ordinary steel, a composition similar to the rust composition of the ballast tank of the actual ship after 6 years has passed. It can be seen that was detected.

[0016]

[Table 1]

Table 2 is a table showing measured values of the corrosion amount of the test material, and it can be seen that the corrosion amount is generally reduced by increasing the addition amount of Cr to the test material.

[0018]

[Table 2]

Next, Table 3 shows the results of measuring the pitting depth of this test material.

[0020]

[Table 3]

The measurement values of the pitting corrosion depth of each test material show 10 places from the deep pitting corrosion depth, but the pitting corrosion depth is the minimum in 2-3% Cr steel, and the pitting corrosion depth is 9%. It can be seen that the pitting depth increases sharply with the above additions. The following evaluation can be obtained from the test results obtained by the apparatus according to the first embodiment of the present invention. From the results of Table 2 and Table 3, it was found that the test material having a small amount of corrosion and not causing pitting corrosion was 2-3% Cr steel.

In seawater pipes and ballast tanks, a steel material that causes localized corrosion in the form of pitting corrosion is not used even if the amount of corrosion is small, so 2-3% Cr steel is optimal. In addition, from the corrosion amount of ordinary steel in Table 2, the test conditions of 40 ° C. and 5 cycles are comparable to the corrosion amount of almost one year in natural seawater. Therefore, in the test by the device of Example 1 of the present invention, about 5 It was found that the device of Example 1 of the present invention was a device that simulated the actual ballast tank well because it had a double corrosion promoting effect. [Embodiment 2] Next, as Embodiment 2 of the present invention, FIG. 2 shows an apparatus in which the structure of the corrosion apparatus is simplified by making it possible to raise and lower the rotary drum.

As shown in the figure, 17 is a drum that raises and lowers the rotary drum 3 to which the test material 4 is attached by a wire 19, and 18 is a rotary drum lifting motor that rotates the drum 17. As a test example, a test was performed in which the test material was repeatedly exposed to 15 days of artificial seawater and 16 atmosphere of 100% humidity for one week.

First, the test material 4 is attached around the rotary drum 3 of the test tank 1. Next, air is sent to the prepared artificial seawater 15 through the gas bubbling pipe 7, and the temperature is raised to a predetermined temperature by the heater 5 while bubbling. In the test tank 1, while controlling the temperature of the artificial seawater 15 to the test temperature by the heater 5 and the temperature sensor 6 in the aqueous solution, air is also bubbled into the artificial seawater 15 through the gas bubbling pipe 7 and bubbling is performed. The gas discharge valve 10 is slightly opened so that the air pressure in the test tank 1 does not rise.

Next, the test is started by applying a rotation speed by the motor 11 having a variable speed and high torque. However, test switching between the artificial seawater 15 and the atmosphere 16 with 100% humidity is possible by raising and lowering the rotating drum 3 by the rotating drum raising / lowering motor 18, and the raising / lowering time is preset. Can automatically control the cycle test. Moreover, the temperature and humidity in the atmosphere can be confirmed by the temperature sensor 8 and the humidity sensor 9.

By the way, when performing a test that is greatly affected by the flow velocity of the artificial seawater 15 through an artificial seawater pipe (not shown), the rotation speed of the variable-speed, high-torque motor 11 is increased and a large flow velocity is applied to the test material 4. Give it. As described above, by raising and lowering the rotating drum 3 in the test tank 1, it is possible to perform a cycle test in the artificial seawater 15 and the atmosphere 16 with 100% humidity.

Further, a test simulating a ballast tank of a ship was conducted by using the test apparatus shown in FIG. Five cycles of repeated exposure to artificial seawater 15 at a temperature of 40 ° C for 1 week and to atmospheric air 16 at a humidity of 100% at a temperature of 40 ° C for 1 week were performed, and the total number of test days was 70 days. The test materials used were 1% Cr steel, 2% Cr steel, 3% Cr steel, 6% Cr steel, 9% Cr steel, 13% Cr steel and ordinary steel, and their rust composition and corrosion amount. , And pit depth was investigated.

Further, the analysis values of the rust composition by X-ray analysis are shown in Table 4. In the table, the rust composition similar to the rust composition of the ballast tank of the actual ship after 6 years has passed for all seven types of test materials. Was detected.

[0029]

[Table 4]

Next, Table 5 shows the measured values of the amounts of corrosion of the seven types of test specimens. As a general result, the amount of corrosion decreased as the amount of Cr added increased.

[0031]

[Table 5]

Then, Table 6 shows the measured values of the pitting depth of the seven types of test test materials.

[0033]

[Table 6]

In the table, the pitting corrosion depths of the test specimens were measured with a depth gauge, and 10 points from the deepest pitting corrosion were listed. The pitting depths were the smallest in the 2% Cr steel and the 3% Cr steel, and it was found that the addition of 9% or more of Cr drastically increased the pitting depth. From the above test results, the Cr steel has a small amount of corrosion, and the 2% Cr steel and the 3% Cr steel have little pitting corrosion. It can be said that there was about a five-fold acceleration effect because it was equivalent to the amount of corrosion in the natural sea for almost one year. From the above experimental results, it can be said that the test apparatus according to the second embodiment of the present invention is a test apparatus simulating an actual ballast tank.

[0035]

[Effect of device]

 With the device of the present invention, it is possible to efficiently and efficiently test a wide variety of test materials under various conditions in a harsh environment, and it is possible to simulate an actual ballast tank. .

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an embodiment according to the present invention.

FIG. 2 is a schematic view showing another example of the embodiment according to the present invention.

[Explanation of symbols]

 1 Test tank 2 Test tank 3 Rotating drum 4 Test material 5 Heater 6 Temperature sensor in aqueous solution 7 Gas bubbling pipe 8 Temperature sensor in gas 9 Humidity sensor 10 Gas discharge valve 11 Motor 12 Chemical pump 13 Valve 14 Preliminary tank 15 Artificial seawater 16 atmosphere 17 drum 18 rotary drum lifting motor 19 wire

Front page continuation (72) Inventor Mikio Kondo 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba Prefecture Kawasaki Steel Corporation Technical Research Headquarters (72) Inventor Shigeo Takazawa 1 Kawasaki-cho, Chuo-ku, Chiba Chiba Iron & Steel Co., Ltd.

Claims (3)

[Scope of utility model registration request] 1. One or more test tanks, one or more preliminary tanks for supplying and receiving a test solution to and from the test tanks, and a rotary drum for mounting a test material provided in the test tanks. A corrosion test apparatus comprising liquid level adjusting means between the test tank and the preliminary tank. 2. The test tank and the auxiliary tank, heating means,
The corrosion test apparatus according to claim 1, further comprising a gas discharge means, a gas bubbling means, and a temperature and humidity monitoring means. 3. A single test tank, a rotary drum for mounting a test material, which is vertically movable in the test tank, heating means for heating a test solution in the test tank, and the test. A corrosion test apparatus comprising: a gas discharging means in a tank, a gas bubbling means in a test solution, and a means for monitoring a temperature of the test solution and a humidity in the test tank.