This test is applicable to parts or equipment that are intended to withstand salty atmospheres. The degree of resistance depends on the severity level selected. Salt can degrade the performance of metal parts and/or non-metal parts. GB/T 2423.18-2000 Environmental testing for electrical and electronic products Part 2: Test Test Kb: Salt spray, alternating (sodium chloride solution) GB/T2423.18-2000 Standard download decompression password: www.bzxz.net

GB/T2423.18-2000
This standard is equivalent to IEC68-2-52: 1996 second edition, and has revised the national standard GB/T2423.18-1985 "Basic environmental test procedures for electric and electronic products (Kb): Alternating salt spray test method". Considering the consistency with IEC standards, this standard deletes the formula of artificial seawater in GB/T2423.183-1985, and changes the international standard from non-equivalent adoption to equivalent adoption. From the date of implementation of this standard, it will replace GB/T2423.18-1985. This standard was proposed by the Climate Subcommittee of the National Technical Committee for Environmental Conditions of Electric and Electronic Products. This standard is under the jurisdiction of the National Technical Committee for Environmental Conditions and Environmental Testing of Electric and Electronic Products. This standard was drafted by the Standard and Metrology Institute of the Ministry of Communications. The main drafters of this standard are Tian Lin and Yuan Shuncai. This standard was first issued in May 1985 and revised for the first time in 2000. This standard is entrusted to the Institute of Standards and Metrology of the Ministry of Communications for interpretation. 216
GB/T2423.18--2000
IEC Foreword
1) IEC (International Electrotechnical Commission) is a worldwide standardization organization composed of national electrotechnical committees (IEC National Committees). The purpose of IEC is to promote international cooperation on all standardization issues in the field of electricity and electricity. To this end, IEC, among other activities, also publishes international standards. International standards are entrusted to technical committees for formulation; any IEC National Committee interested in the issues under study may participate in the formulation work. International organizations, governmental and non-governmental organizations associated with IEC may also participate in the formulation of standards. IEC and the International Organization for Standardization (ISO) work closely under the terms of the agreement between the two parties. 2) The representatives of the technical committees come from all the relevant national committees. Therefore, the resolutions or agreements of the IFC on technical issues can only express the consensus of the majority of representatives on the relevant issues as accurately as possible. 3) The documents produced by IEC are recommended for use by various countries, published in the form of standards, technical reports or guidelines, and accepted by the national committees in the sense of the former.
4) To promote international uniformity, the IEC National Committees undertake to adopt IEC International Standards as far as possible in their national and regional standards. Any differences between IEC standards and corresponding national or regional standards shall be clearly indicated in the latter. 5) IEC does not specify any procedures for marking the approval mark and therefore assumes no responsibility for any equipment claiming to comply with IEC standards. 6) It is worth noting that some parts of this standard may involve patent rights. IEC will not be responsible for identifying any or all such patent rights.
International Standard IEC68-2-52 was prepared by Technical Committee 50B (Climatic Testing) of IEC Technical Committee 50 (Environmental Testing). The second edition of this standard cancels and replaces the first edition of 1984 and is a technically revised version. The text of this standard is based on the following documents: (FDIS) Final Draft Standard
50B/363/FDIS
Voting Report
50B/374/RUDwww.bzxz.net
Full information on the approval of this standard can be found in the voting report indicated in the table above. 217
1 Scope
National Standard of the People's Republic of China
Environmental testing for electric and electronic products
Part 2: Tests
Test Kb: Salt mist, cyclic (sodium chloride solution)Environmental testing for electric and electronic productsPart 2: Tests-
Test Kb; Salt mist, cyclic (sodium chloride solution)GB/T 2423. 18---2000
idt IEC 68-2-52:1996
Replaces GB/T2423.18---1985
This test is applicable to components or equipment that are intended to withstand salty atmospheres, the degree of which depends on the severity level selected. Salt can degrade the performance of metal parts and/or non-metal parts. The mechanism of salt corrosion of metallic materials is electrochemical corrosion, while the degradation of non-metallic materials is caused by complex chemical reactions between salt and materials. The corrosion rate depends largely on the amount of oxygen-containing salt solution supplied to the surface of the test sample, the temperature of the sample and the temperature and humidity of the environment.
In addition to showing the corrosion effect, this test can also show the degree of deterioration of certain non-metallic materials due to the absorption of salt. In the following test method, the time for spraying the salt solution is sufficient to fully wet the entire specimen. Since this wetting is repeated after storage under damp and hot conditions (severe levels (1) and (2)), and in some cases it is supplemented by storage in the standard test atmosphere (severe levels (3) to (6)), the effects of the natural environment can be reproduced more effectively.
Severe levels (1) and (2) are suitable for testing products used in marine environments or in offshore areas. Severe level (1) is suitable for testing products that are exposed to this environment during most of their service life (such as ship radars and deck equipment). Severity level (2) is suitable for testing products that may be frequently exposed to the marine environment but are usually protected by enclosures (such as marine equipment commonly used on ship bridges or in control rooms). In addition, severity levels (1) and (2) are usually used as general corrosion tests in component quality assurance programs. Severity levels (3) to (6) are suitable for products that are often used in a salty atmosphere and a dry atmosphere, such as automobiles and their parts.
Therefore, severity levels (3) to (6) contain an additional storage under standard test atmospheric conditions compared to severity levels (1) and (2). In practice, dry atmosphere may occur during interruptions in work, such as on weekends. This drying phase included in severity levels (3) to (6) leads to corrosion mechanisms that may be completely different from those under constant damp heat conditions. The test method is accelerated compared to the use conditions. However, this test method does not make it possible to establish a comprehensive acceleration factor for different types of samples (see IEC355).
2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T2421-1999 General rules for basic environmental testing procedures for electric and electronic products (idtIEC68-1:1988) GB/T2423.3-1993 Environmental testing for electric and electronic products Test Ca: Steady damp heat test method (eqv IEC 68-2-3:1985)
Approved by the State Administration of Quality and Technical Supervision on January 3, 2000 218
Implementation on August 1, 2000
GB/T 2423. 18--2000
GB/T2424.10-1993 General Guidelines for Accelerated Atmospheric Corrosion Tests for Environmental Testing of Electrical and Electronic Products (eqIEC355:1971)
3 General description of the test
Severity levels (1) and (2) divide the test procedure into several specified spray cycles, each of which is followed by a wet heat storage cycle; the spray temperature is between 15℃ and 35℃, and the storage conditions are a temperature of 40℃±2℃ and a relative humidity of (93=2)%. Severity levels (3), (4), (5) and (6) divide the test procedure into several specified test cycles. Each test cycle consists of: first four spray cycles, each of which is followed by a wet heat storage cycle, and after the spray and wet storage, a storage cycle is performed under the standard atmospheric conditions for the test. The humidity of the spray is between 15°C and 35°C; the wet heat storage conditions are: temperature 40°C ± 2°C, relative humidity (93=)%; the standard atmospheric pressure for the test is: temperature 23°C ± 2°C, relative humidity 45% ~ 55%. If the spray and storage are carried out in different test boxes (rooms), care should be taken to avoid loss of salt solution attached to the sample and damage to the sample when transferring the test sample.
The sample should never be powered on during spraying, and it is usually not powered on during storage. 4 Test equipment
4.1 Salt spray box
The salt spray test box (room) should be made of materials that do not affect the corrosion effect of salt spray. The detailed structure of the salt spray test box (room), including the method of generating salt spray, is optional, but the following conditions must be met: a) The conditions in the salt spray box should be within the specified range; b) The salt spray box has a large enough volume, constant and uniform conditions (not affected by flow), and is not affected by the test sample; c) The salt spray shall not be sprayed directly onto the test sample during the test; d) The liquid condensed on the top plate, side walls and other parts of the salt spray box shall not drip on the sample; e) The salt spray box should be equipped with appropriate ventilation holes to prevent the air pressure in the box from increasing and to distribute the salt spray evenly. The exhaust end of the ventilation hole should be able to avoid strong exhaust to avoid forming strong airflow in the salt spray box. 4.1.1 Sprayer
The design and structure of the sprayer should be able to produce finely dispersed, moist, and dense salt spray. The material used to make the sprayer should not react with the salt solution.
4.1.2 The salt solution used for spraying should not be reused. 4.1.3 Air source
If compressed air is used, the air should be basically free of all impurities, such as oil, dust, etc., when entering the nozzle. A device that can humidify the compressed air should be provided so that the humidity of the compressed air meets the requirements of the test conditions. The air pressure should be suitable for producing finely dispersed dense salt spray.
To ensure that the nozzle of the sprayer is not blocked by salt precipitates, the relative humidity of the air at the nozzle should not be less than 85%. A satisfactory method is to make the air pass through a water tower that automatically maintains the water level in the form of fine bubbles. The water temperature in the water tower must not be lower than the temperature of the salt spray chamber.
The air pressure should be adjustable to ensure the collection rate specified in 9.2. 4.2 Wet heat chamber
The wet heat chamber should meet the requirements of GB/T2423.3, that is, maintain a relative humidity of (93=2)% and a temperature of 40C±2C. 4.3 Standard atmosphere chamber
The test chamber shall meet the requirements of 5.2 (row 2 in the table, width range) in GB/T2421-1999, that is, maintain a relative humidity of 45% to 55% at a temperature of 23C±2℃.
5 Salt solution
5.15% sodium chloride solution (NaC)
GB/T2423.18-2000
5.1.1 The test salt shall be high-quality sodium chloride (NaCl), the content of sodium iodide in the lower weight shall not exceed 0.1%, and the total impurity content shall not exceed 0.3%
The mass percentage concentration of the salt solution is 5%±1%. When preparing the salt solution, (5±1) parts of salt (by mass) shall be dissolved in 95 parts of distilled water or deionized water (by mass). Note: The relevant specifications may require other salt solutions. Their composition and characteristics (concentration, pH value, etc.) shall be clearly stated in the specification, such as the special effects of simulating the marine environment.
5.1.2 The pH of the salt solution shall be between 6.5 and 7.2 at a temperature of 20°C ± 2°C. The pH shall be maintained within this range during the test; for this purpose, the pH may be adjusted with dilute hydrochloric acid or sodium hydroxide solution, provided that the concentration of sodium chloride remains within the specified range. The pH shall be determined for each new batch of solution.
6 Severities
6.1 Severities are defined as follows:
Severities (1) and (2):
refers to the combination of the number of spray cycles and the duration of the wet heat storage following each spray cycle. Severity (3) and (6);
refers to the number of test cycles. Each test cycle has four spray cycles and a wet heat storage cycle immediately following each spray cycle, followed by an additional storage cycle at the standard atmospheric pressure used for the test. 6.2 The relevant specification shall specify which of the following six severity levels shall be used: Severity level (1): four spray cycles, each for 2 h, followed by a 7-day condensation heat storage cycle after each spray cycle. Severity level (2): three spray cycles, each for 2 h, followed by a 20-22 h damp heat storage cycle after each spray cycle. Severity level (3): a test cycle containing four spray cycles, each for 2 h; each spray cycle is followed by a 20-22 h damp heat storage cycle, followed by a three-day storage cycle in the test standard atmosphere (temperature 23°C ± 2°C, relative humidity 45% to 55%).
Severity level (4): two test cycles specified in severity level (3). Severity level (5): four test cycles specified in severity level (3). Severity level (6): eight test cycles specified in severity level (3). 6.3 Figure 1 shows a schematic diagram of the combined time scale for all test severity levels. 7 Initial inspection
Carry out visual inspection on the test sample. If necessary, conduct electrical and mechanical property tests according to the requirements of relevant specifications. 8 Pretreatment
Relevant specifications should specify the cleaning procedures to be carried out immediately before the test, and should also indicate whether the temporary surface protection layer should be removed. Note: The cleaning method used should not affect the effect of salt spray on the sample, and should not cause secondary corrosion. Before the test, try to avoid touching the surface of the test sample with your hands.
9 Test
9.1 Place the test sample in the salt spray chamber and spray salt spray for 2 hours at 15C~~35C. 9.2 The salt spray should fill all exposed spaces in the salt spray chamber. Place a clean collector with a horizontal collection area of ​​80cm at any point in the subspace, and collect an average of 1.0ml~2.0ml of solution per hour in each collection cycle. At least two collectors should be used. The collector should be placed in a position that is not covered by the test sample and avoid condensation from all directions entering the collector. Note: In order to obtain accurate test results, when calibrating the spray rate of the test salt spray chamber, the minimum spray period should not be less than 8h. 9.3 Severity level (1) and (2) After each spraying, the test sample shall be transferred to a wet heat chamber for storage. The storage conditions shall be in accordance with the provisions of GB/T2423.3: temperature is 40°C ± 2°C and relative humidity is (93=2)%
Spray according to the provisions of 9.1 and store according to the provisions of 9.3, which constitutes a cycle. The number of cycles and storage time required by the severity level shall be determined in accordance with the requirements of 6.2. 9.4 Severity level (3) to (6)
After each spraying, transfer the test sample to a damp heat chamber. Store for 20h to 22h under the conditions specified in GB/T 2423.3 (temperature 40℃ ± 2C, relative humidity (93)%). Repeat this process three times. Then, the test sample should be stored for 3 days under the standard test atmosphere (temperature 23℃ ± 2C, relative humidity 45% ~ ~ 55%). After four spraying cycles (see 9.1) and the damp heat storage cycle in 9.4, storage in the standard test atmosphere for 3 days constitutes a test cycle.
Number of test cycles required by the severity level The number shall be in accordance with the provisions of 6.2. 9.5 When transferring the test sample from the salt spray chamber to the wet heat chamber, the loss of salt solution on the sample should be minimized. Note: If the salt spray chamber can maintain the humidity and temperature conditions specified in GB/T.2423.3, the sample can continue to be stored in the salt spray chamber during the storage stage. 9.6 If the test sample consists of more than one part, these parts or these parts and other metal parts must not contact each other, and their arrangement should not affect each other. 10 Recovery (at the end of the test)
The relevant specifications should indicate whether the sample should be cleaned. If it is necessary to clean it, it should be cleaned in running tap water for 5 minutes, and then washed with distilled water or deionized water. Rinse, then shake by hand or blow off water droplets with water, dry at 55°C ± 2°C for 1 hour, then cool under controlled recovery conditions (5.4.1 in GB/T2421-1999) for 1 hour to 2 hours. The temperature of the washing water should not exceed 35°C. :11 Final test
The test samples shall be subject to appearance, size and function tests as specified in the relevant specifications. The relevant specifications shall provide the basis for acceptance or rejection of the test samples. 12 Information to be given in the relevant specifications
When the relevant specifications adopt this test, the following details shall be given as far as possible according to the applicable degree. The relevant specifications shall provide the information required by the following chapters, especially Chapters marked with (*) are mandatory. Chapter number
a) Salt solution, if different from that described in 5.1.1 b) Appropriate severity level
c) Initial test
d) Pretreatment
e) Recovery
f) Final test
Severity level
Wet heat storage
1 cycle - 7 days
Wet heat storage
1 cycle - 24 hours
Wet heat storage
1 cycle = 24 hours
Test starting point
3 cycles = 3 days
GB/T2423.18--2000
4 cycles=28 days
4 cycles
1 test cycle=7 days
2 test cycles
4 test cycles
8 test cycles
Spraying phase: 2h
Figure 1 Schematic diagram of the time scale for different test severity levels (1) to (6)3 days
Stored in the test environment
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