The judgment standard of reliability salt spray test results is divided into 1 to 10 levels

Date：2022-07-26 15:59:27Views：2484

Salt spray test is an environmental test that uses salt spray test equipment to evaluate the corrosion resistance of products or metal materials. It is divided into two categories, one is natural environmental exposure test, and the other is artificial accelerated simulated salt spray environment test. Among them, the artificial simulated salt spray environment test is to use the salt spray test chamber and use the artificial method to create the salt spray environment in its volume space to assess the quality of salt spray corrosion resistance of products. The salt concentration of chloride in salt fog environment is several times or dozens of times of that in natural environment, which greatly improves the corrosion rate.

Salt spray test standard and judgment of test results

A standard is a unified provision for repeated things and brief descriptions. The salt spray test standard is the salt spray test conditions, such as temperature, humidity, sodium chloride solution concentration and pH. in addition, it also puts forward technical standards for the performance of the salt spray test chamber. According to the characteristics of salt spray test, metal corrosion rate and sensitivity to salt spray, the salt spray test standard of the same commodity is selected.

The following are the salt spray test standards, such as gb/t2423.17-1993 basic environmental test procedures for electronic and electrical goods Test Ka: salt spray test method, gb/t2423.18-2000 environmental test for electronic and electrical goods part II Kb: salt spray, alternating (sodium chloride solution), gb5938-86 "test method for corrosion resistance of metal coatings and chemical treatment layers of light industrial products" and gb/t1771-91 "determination of resistance of paints and varnishes to neutral salt spray".

The purpose of salt spray test is to evaluate the quality of salt spray corrosion resistance of commodities or metal materials. The results of salt spray test are the judgment of product quality and the key to correctly measure the quality of salt spray corrosion resistance of commodities or metals.

The judgment methods of salt spray test results include rating method, weighing method, corrosive substance appearance method and corrosion data statistical analysis method.

1. The rating judgment method is to divide the percentage of corrosion area and total area into several grades according to a certain method, and take a certain grade as the basis for qualified judgment, which is suitable for the evaluation of flat plate samples;

2. Weighing judgment method is to judge the corrosion resistance quality of samples by weighing the weight of samples before and after corrosion test and calculating the weight of corrosion loss, which is especially suitable for evaluating the corrosion resistance quality of a certain metal;

3. The judgment method of corrosive substances is a qualitative judgment method. It judges the samples according to whether the products are corroded after the salt spray corrosion test. This method is mainly used in general product standards;

4. The statistical analysis method of corrosion data brings the method of designing corrosion tests, analyzing corrosion data and determining the confidence range of corrosion data. It is mainly used to analyze and count the corrosion status, rather than the quality of specific goods

It is mainly applicable to the artificial salt spray environment test in the industries of hardware, electroplating, electronic parts, chemical coating, baking paint, automobile, screw, spring, organic and inorganic film, anodic treatment, antirust oil, etc.

If the same specimen is used to complete multiple climate tests, in most cases, it is recommended to conduct salt spray test after other tests. Salt deposits can interfere with the results of other tests. Generally, the same test piece is not used for salt spray, mold and damp heat test. If special needs, salt spray test should also be carried out after mold and damp heat test.

Judgment standard of salt spray test

1. Gb/t 6461-2002 rating of samples and test pieces after corrosion test of metal and other inorganic coatings on metal substrates;

2. ISO 10289-1999 rating of test specimens and parts for corrosion tests of metallic and other inorganic coatings on metal products;

The specific rating of salt spray test is from 1 to 10

Level 1: the defect area accounts for 25% - 50%, which is a serious corrosion phenomenon;

Level 2: the defect area accounts for 10% - 25%, and the appearance rating is I. The sample has corrosion of the base metal;

Grade 3: the defect area accounts for 5% - 10%, and the appearance rating is h. There is a very thick corrosion product layer or pitting on the surface of the sample, and there is deep pitting;

Grade 4: the defect area accounts for 2.5% - 5%, the appearance rating is g, and there is a thick corrosion product layer or pitting on the surface of the sample;

Grade 5: the defect area accounts for 1.0% - 2.5%, and the appearance rating is F. there are corrosion products or pitting corrosion on the sample surface, and one of them is distributed on the whole sample surface;

Grade 6: the defect area accounts for 0.5% - 1.0%, and the appearance rating is e. the surface of the sample is seriously tarnished, or there is a thin layer of corrosion products or pitting on the local surface of the sample;

Grade 7: the defect area accounts for 0.25% - 0.5%, the appearance rating is D, and the surface of the sample is seriously tarnished or slightly corroded;

Grade 8: the defect area accounts for 0.1%~0.25%, the appearance rating is C, and the sample surface is seriously discolored or has very slight corrosion;

Grade 9: the defect area accounts for no more than 0.1%, the appearance rating is B, and the sample surface has slight to moderate discoloration

Grade 10: no defect area, appearance rating A, no change in the surface appearance of the sample.

3. ASTM d1654-2008 Standard Test Method for evaluation of paint or coating specimens in corrosive environments.

The above is the reliability salt spray test related content of the core detection Xiaobian finishing, and I hope it will be helpful to you. Shenzhen Chuangxin Online Testing Technology Co., Ltd. is a well-known professional testing institution for electronic components in China, with 3 standardized laboratories covering an area of more than 1000 square meters. The scope of testing services covers: electronic component testing and verification, IC authenticity identification, product design and material selection, failure analysis, function testing, factory incoming material inspection, component X-ray testing, taping and other test items.