JPH1062333A - Corrosion resistance test equipment of metallic material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a test equipment in which a corrosion resistance test method of metallic materials capable of providing a test result having a high correlation with the durability of an actual machine can be executed. SOLUTION: In a corrosion resistance test equipment having a deposit supplying chamber 2a and a corrosion promoting chamber 2b which are allowed to communicate each other in an opening part 4 and interrupted by closing a door 5 provided on the opening part 4 so that a test piece S can be carried between the deposit supplying chamber 2a and the corrosion promoting chamber 2b through the opening part 4, a deposit for promoting the corrosion is adhered to the surface of the test piece S in the deposit supplying chamber 2a, and the corrosive liquid for promoting corrosion is sprayed, or air having prescribed temperature and humidity is supplied into the chamber 2b in the corrosion promoting chamber 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrosion resistance test apparatus for performing a corrosion resistance test of a metal material, particularly a heat exchanger of an automobile or the like.

[0002]

2. Description of the Related Art Aluminum or an alloy thereof is often used as a material for various heat exchangers for automobiles and the like. Further, the heat exchanger is exposed to polluted air such as exhaust gas in its use environment, and is repeatedly wetted and dried due to rainfall and sunshine, and corrosion is inevitable during long-term use. Therefore, in order to accurately predict the durability of a product and to develop a product, a corrosion resistance test of the product or a metal material is indispensable.

[0003] The corrosion resistance test of various metallic materials is performed in a corrosion-promoting environment for a test specimen in order to perform the test in a short time.
As a general corrosion resistance test method, for example, a salt spray test method (JIS Z2371) in which salt water is continuously sprayed, a CASS test (JIS H8681) in which acid water is sprayed, S
WAAT and the like are known, and these test methods are widely adopted as a corrosion resistance test of a heat exchanger. In addition, as a corrosion resistance test method particularly for automobile parts, there is JASO mode M609-91 CCT of the Japan Automobile Association, and this test method in which salt spraying and drying are repeated in a constant cycle is widely adopted.

[0004]

However, of the above-mentioned test methods, the salt water spray method and the CCT method require that the surface of the metal material be covered with a water film having a thickness of several tens μm or more due to the long spray time of the salt water. Is maintained for a long time, and corrosion occurs and progresses in a form different from that of the actual machine mainly composed of pitting corrosion. Also, the CASS test and SWAAT using an acidic solution are different from the actual corrosion mode of the actual machine.

[0005] Therefore, in each of the above-mentioned methods, a heat exchanger having a good test result is not always excellent in durability as an actual machine, and it is difficult to predict the product life in the market based on the test results and to develop a highly corrosion-resistant material. Was.

[0006] In view of such technical background, the applicant of the present invention, in order to obtain a test result highly correlated with the durability of an actual machine, adheres powdery deposits that promote corrosion to test specimens,
We proposed a corrosion resistance test method for metal materials to perform a salt spray or dry-wet corrosion promotion test.

[0007] However, in the conventional corrosion resistance test, there is no test apparatus for performing the above-mentioned test method because no powder deposit is used. An object of the present invention is to provide a test apparatus for performing the above-described test method.

[0008]

According to the present invention, there is provided an apparatus for testing the corrosion resistance of a metallic material according to the present invention.
A specimen supply chamber (2a) and a corrosion accelerating chamber (2b) which communicate with each other in (4) and are shut off by closing a door (5) provided in the opening (4), and (S)
A corrosion resistance test apparatus that can be transported between the attached matter supply chamber (2a) and the corrosion promotion chamber (2b) through the opening (4), wherein the attached matter supply chamber (2a) Attach a substance that promotes corrosion to the surface of the test specimen (S), and in the corrosion promotion chamber (2b), spray a corrosion-promoting solution into the chamber (2b) or spray the corrosion liquid into the chamber (2b). It is characterized in that the air is supplied at a predetermined temperature and humidity.

This corrosion resistance test apparatus is provided with two types of test chambers, an adhering substance supply chamber (2a) and a corrosion promotion chamber (2b) communicating with each other at the opening (4), and the door (5) of the opening (4). ) Is closed and 2
The chambers (2a) and (2b) are shut off, so that the surface of the specimen (S) is treated with a substance that promotes corrosion, and is maintained in a corrosion-promoting environment such as a spray of corrosive liquid or a wet or dry atmosphere. Two types of processing can be performed. Also,
Since the specimen (S) can be transported between the two chambers (2a) and (2b) through the opening (4), the treatment in one chamber (2a) is performed, and then the specimen (S) Was transported to the other chamber (2b) for processing, and was again able to be transported to the other chamber (2a) freely, and by repeating this, the adhered substance was deposited on the surface of the test specimen (S). A cycle test in which the state is maintained in a corrosion-promoting environment can be performed.

[0010] The attached matter supply chamber (2a) is adapted to spray and apply the powdered attached matter to the specimen (S) by feeding compressed air (A). That the suspension of the deposit is applied to the specimen (S) by shower coating, or that the specimen (S) is immersed in the suspension of the deposit to adhere. It is preferable that it is made as follows.

By adopting each of the above-described methods as a method of supplying the deposit, the operation of supplying the deposit can be easily performed.
In addition, it can be uniformly attached to the surface of the test specimen.

[0012]

FIG. 1 shows a first example of an apparatus for testing the corrosion resistance of a metal material according to the present invention.

In this test apparatus (1), the test chamber (2) is divided into two by a partition wall (3) into a deposit supply chamber (2a) and a corrosion promotion chamber (2b). )) At the opening (4). In addition, the opening
(4) is provided with a door (5) that is opened and closed by vertical drive, and the two chambers (2a) and (2b) are shut off by closing the door (5).

The deposit supply chamber (2a) is provided with a nozzle (6) for ejecting powder deposits. In the attached matter supply chamber (2a) shown in this example, an outdoor powder storage chamber (7)
The deposits stored in the nozzle are blown out from the nozzle (6) by the compressed air (A) and sprayed onto the specimen (S). On the other hand, the corrosion promotion chamber (2b) is supplied with a corrosive liquid adjusted to a predetermined temperature from the outside of the chamber (2b) through a nozzle (8) in a spray state, Humid air and dry air adjusted to temperature and humidity are supplied through respective supply ports (9a) and (9b) so that the indoor temperature and humidity are maintained. As a method of spraying the etchant, a well-known method used in a conventional salt spray test (JISZ2371) or the like may be used. In addition, well-known means for adjusting and supplying the dry air and the wet air may be appropriately used. In FIG. 1, reference numeral (10) denotes an exhaust / drain outlet for discharging the mist of the corrosive liquid, dew condensation water, and air outside the room.

The test apparatus (1) includes a test object (S)
Is installed (not shown), and when the door (5) is opened, the specimen (S) is moved through the opening (4) of the partition wall (3) to the deposit supply chamber. (2a) and the corrosion promotion chamber (2b). As this transporting device, a known device may be appropriately used, and the test piece (S)
And a mechanism for moving the platform on which is mounted using a slide rail.

In addition, opening and closing of the door (5), transport of the specimen (S),
The supply of the deposit, the adjustment and supply of the temperature and humidity of the corrosive liquid, the adjustment and supply of the temperature and humidity of the air, and the setting of the conditions of the cycle test described in detail later are controlled by a control device (not shown).

FIG. 2 shows a second example of the test apparatus according to the present invention.

The test apparatus (11) is the same as the test apparatus (1)
Only the structure of the deposit supply chamber (12a) is different from that of the first embodiment, and the corrosion promotion chamber (2b), the transfer device, and the control device are the same.

In the adhering matter supply chamber (12a), the adhering matter is supplied as a suspension of water to the specimen (S). The suspension stored in the tank (17a) is fed by a pump (17b) and shower-applied from the nozzle (16) to the specimen (S). Then, when the moisture evaporates after the application, deposits are deposited on the surface of the test specimen (S) and are retained.

FIG. 3 shows a third example of the test apparatus according to the present invention.

The test apparatus (21) is the same as the test apparatus (1)
Only the structure of the deposit supply chamber (22a) is different from that of the first embodiment, and the corrosion promotion chamber (2b), the transfer device, and the control device are the same.

In the deposit supply chamber (22a), a suspension in which the deposit is dispersed in water is filled in a liquid tank (27), and a test specimen is
(S) is applied by dipping in the suspension. Test specimen
After immersing (S) for a certain period of time, pulling it up and evaporating the water, deposits deposit on the surface of the specimen (S) and are retained.

The test device (31) shown in FIG. 4 is a modification of the test device (21) shown in FIG. 3, and is provided with a deposit supply chamber (32a) having a suspension liquid tank (37) and a corrosion promoting device. The chamber (32b) is a test device arranged vertically. For this reason, the door (35) is opened and closed horizontally, and the transport device is of a lifting type.

In the above test apparatus (1), (11), (21), (31), the deposits supplied in the deposit supply chambers (2a), (12a), (22a), and (21a) and the corrosion promotion chamber (2b) The following are suitable as the corrosion liquid sprayed in (32b).

The deposit is a mixed powder comprising a corrosion accelerating component for accelerating corrosion of the specimen and a carrier for adhering and holding the corrosion accelerating component and moisture to the specimen. Then, in a state where the corrosion promoting component is adhered and held on the specimen, the corrosion is promoted and the corrosion mode is pitted by spraying a corrosive liquid in a corrosion promoting chamber or by holding the specimen in a dry or wet environment. Approximate the corrosion pattern of the actual machine mainly composed of

As the above-mentioned corrosion promoting component, in addition to NaCl which is a general corrosion promoting substance, FeCl ₃ , CaCl ₂ , AlCl ₃ , C
metal chlorides such as uCl ₂ , Fe ₂ O ₃ , Fe ₃ O ₄ , C
In a corrosion resistance test of metal oxides such as uO and CuO ₂ , and particularly, in a corrosion resistance test of an automobile part such as a heat exchanger, those containing carbon black, graphite or the like as a carbon component derived from an exhaust gas component are preferable. Species or two or more species are used in combination.

It is preferable that the carrier uses a component derived from sand, soil, dust and the like in order to approximate the corrosion form of the actual machine. Specifically, kaolin, CaSO ₄ ,
Examples include SiO ₂ , CaCO ₃ , Al ₂ O ₃ , CaO, and MgO.

The above-mentioned corrosion promoting component and the carrier have a particle size of 0.1 to 100 in order to make it easy to adhere to and hold on the specimen.
It is preferable to use one having a μm particle size adjusted.

[0029] Such a deposit is applied to the test apparatus (1) shown in FIG.
In the test apparatus shown in FIGS. 2 to 4, the powder is used as it is and dispersed in water. The preferred mixing ratio of the corrosion promoting component and the carrier in the deposit depends on the supply method. In the case of a liquid, the corrosion promoting component: carrier: water =
2 to 30: 5 to 50:40 to 90 are preferable, and especially 5 to
20:10 to 50:50 to 80 are preferred. In addition, in the case of powder, it is easier to maintain the adhered state when a larger amount of the carrier is blended than in the case of the liquid. 4
0: 60-80 is preferred. In addition, in the test apparatus described above, in which the deposit is supplied as a liquid (11), (21), and (31), in order to promote corrosion, the pH of the liquid is adjusted to an acidity of 1.0 to 9.0 to a weak alkalinity. Adjustment is preferred.

It is preferable that the supply amount of the deposit is 2-80 g / m ² in terms of dry weight based on the surface area of the test specimen. Further, the supply processing time of the attached matter is not particularly limited, as long as the predetermined amount of the attached matter is attached.

The corrosion liquid sprayed in the corrosion promotion chamber (2b) may be a 5% NaCl aqueous solution conventionally used in the JIS Z2371 salt water spray test method or the like, or may be a pipe, Salt water to which various components derived from exhaust gas, earth and sand, etc. are added can be suitably used. As a specific example of such a corrosive liquid, NaCl: 2
10%, Fe ³⁺ : 10 to 5000 ppm, Cu ²⁺ : 1
1000 ppm and Ca ²⁺ : 10 to 5000 ppm, SO ₄ ²⁻ : 10 to 10000 ppm, N
O ₃ ⁻ : 10 to 10000 ppm, CO ₃ ²⁻ : 10 to 5
000 ppm, HCO ₃ ⁻ : Some contain at least one of 10 to 5000 ppm.

In spraying the corrosion liquid, an average of 10 to 1 is applied to the surface of the test specimen in order to approximate the corrosion form of the actual machine.
It is preferable to form a 00 μm water film and keep the entire surface constantly wet with the corrosive liquid. For this purpose, the spray amount is preferably 5 to 50 μl / cm ² · hr. In addition, in order to secure an appropriate corrosion rate, the temperature of the etchant is 10 to 10.
The temperature of 50 ° C. and the time of spraying the etchant are preferably 0.5 to 5 hours.

In a humid environment, 30 to 50
It is preferable to supply air at 80 ° C. and 80% to 98% RH to form a thin water film of 0.5 to 10 μm on the surface of the test specimen. Further, the wet environment holding time is preferably 2 to 23 hours. The supply air in a dry environment is 40 to 70 ° C.
It is preferably 60% RH or less, and the drying environment holding time is preferably 2 hours or less.

In the corrosion resistance test using the test apparatus as described above, a cycle test in which supply of attached matter, spraying of a corrosive liquid, holding of a dry environment, and holding of a wet environment can be appropriately performed. As an example of the corrosion resistance test, a cycle test method in which four steps are defined as one cycle and an arbitrary cycle is performed according to the use of the test body and the required corrosion resistance is shown. The operation will be described.

(First Step: Deposited Material Supply Chamber, Deposited Deposit) The test sample (S) is placed in the debris supply room (2a), the door (5) is closed and the specimen (S) is cut off from the corrosion promoting chamber (2b). . And compressed air
The deposits stored in the powder storage room (7) by (A)
Spray from (8) and spray apply to the specimen (S).

(Second Step: Corrosion Acceleration Chamber, Corrosion Liquid Spray) Open the door (5), and transfer the specimen (S) from the opening (4) of the partition wall (3) by the transfer device to the deposit supply chamber (2a). ) To the corrosion promotion chamber (2b). Then, the door (5) is closed again to shut off the adhering matter supply chamber (2a), and then a corrosive liquid adjusted to a predetermined temperature is sprayed into the chamber (2b).

(Third Step: Corrosion Accelerating Chamber, Keeping Humid Environment) In the corrosion accelerating chamber (2b), the residual mist of the corrosive liquid is exhausted and discharged.
Drain from drain (10). Then, the test specimen (S)
While the air is kept in the corrosion promoting chamber (2b), humid air adjusted to a predetermined temperature and humidity outside the room is supplied from the supply port (9a) for a certain period of time.

(Fourth Step: Corrosion Acceleration Chamber, Keeping Dry Environment) Subsequently, while the test sample (S) is placed in the corrosion acceleration chamber (2b), dry air adjusted to a predetermined temperature and humidity is supplied outside the room. Supply from mouth (9b) for a certain period of time. After maintaining the drying environment for a certain period of time, the door (5) is opened, and the specimen (S) is transferred from the corrosion promotion chamber (2b) to the deposit supply chamber (2a) through the opening (4) of the partition wall (3) by the transfer device. ) To prepare for the first step of the next cycle.

In this test example, the operation of the test apparatus (1) for supplying the adhered matter as powder has been described.
In the test apparatus (11), the powder spray application in the first step is a shower application of the attached matter suspension, and the test apparatus shown in FIG.
In (21), the powder spray application in the first step is only the dip coating of the attached substance suspension, and the second to fourth steps are common operations. In the test device (31) of FIG.
The difference from the operation of the test apparatus (21) in FIG. 3 is that the transport direction of the test specimen is vertical.

Although four steps are performed in the test example described above, steps can be omitted and the order of the steps can be freely changed.

[0041]

As described above, the apparatus for testing corrosion resistance of metallic materials according to the present invention communicates with the deposit supply chamber which communicates with the opening and which is shut off by closing the door 5 provided in the opening. A corrosion resistance test apparatus comprising a corrosion promotion chamber, and capable of transporting a test specimen between the deposit supply chamber and the corrosion promotion chamber through the opening. A substance that promotes corrosion is attached to the surface of the test specimen, and in the corrosion-promoting chamber, a corrosive liquid that promotes corrosion is sprayed into the chamber, or air at a predetermined temperature and humidity is supplied to the chamber. Therefore, it is possible to easily carry out a corrosion resistance test method in which corrosion is promoted in a state in which a powdery corrosion promoting substance is adhered. As a result, it is possible to reproduce the corrosion form similar to the actual machine mainly composed of pits, and to obtain test results highly correlated with the durability of the actual machine, and to accurately predict the durability of products in the market based on the test results. In addition to the above, it is possible to accurately develop corrosion-resistant materials and products according to applications.

[0042] The adhering substance supply chamber is configured to spray and apply the adhering substance in powder form to a test piece by feeding compressed air, and a suspension of the adhering substance. Is applied to the specimen by shower coating, or when the specimen is immersed in the suspension of the attached substance and attached, the work of supplying the attached substance is particularly performed. The test can be easily performed and can be uniformly attached to the surface of the test body, so that a highly reliable test result can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a first example of a metal material corrosion resistance test apparatus according to the present invention.

FIG. 2 is a schematic view showing a second example of the metal material corrosion resistance test apparatus according to the present invention.

FIG. 3 is a schematic diagram showing a third example of the metal material corrosion resistance test apparatus according to the present invention.

FIG. 4 is a schematic view showing a fourth example of a metal material corrosion resistance test apparatus according to the present invention.

[Explanation of symbols]

 1,11,21,31… Test equipment 2a, 12a, 22a, 32a… Adhered matter supply chamber 2b, 32b… Corrosion accelerating chamber 4… Opening 5… Door S… Test body A… Compressed air

Claims (4)

[Claims] 1. A communication at an opening (4),
It is provided with a deposit supply chamber (2a) and a corrosion promotion chamber (2b) which are shut off by closing a door (5) provided in the opening (4), and the specimen (S) is connected to the opening (4). (4) is a corrosion resistance test apparatus that can be transported between the adhesion substance supply chamber (2a) and the corrosion promotion chamber (2b) through the adhesion substance supply chamber (2a)
In the above, a substance which promotes corrosion is attached to the surface of the specimen (S), and in the corrosion promotion chamber (2b), a corrosion promoting liquid is sprayed into the chamber (2b), or the chamber (2b) An apparatus for testing the corrosion resistance of a metal material, wherein air having a predetermined temperature and humidity is supplied into the inside. 2. The adhering matter supply chamber (2a) is adapted to spray and apply the powdered adhering matter to a test piece (S) by feeding compressed air (A). An apparatus for testing corrosion resistance of a metal material according to claim 1. 3. The corrosion resistance of a metal material according to claim 1, wherein the deposit supply chamber (2a) is adapted to apply a shower of the suspension of the deposit to a test specimen (S) to cause the suspension to adhere. Testing equipment. 4. The corrosion resistance of a metallic material according to claim 1, wherein said deposit supply chamber (2a) is adapted to immerse and attach a specimen (S) in a suspension of said deposit. Testing equipment.