Composite Salt Fog Test/Reliability Test /CNAS/Cma Intelligence

2. Composite salt spray test:
Composite salt spray test, also called cyclic corrosion test, cyclic corrosion test (CCT) is mainly used in the automotive industry, on the basis of constant salt spray test introduced the high temperature, humidity, low temperature, drying parameters, as far as possible considering many factors in the natural environment, the purpose to achieve higher correlation with the natural environment test results. The purpose of the composite salt spray test is to confirm the ability of the object to tolerate the salt spray environment, and to simulate the actual use of the salt mist and moisture. It is suitable to assess the electrochemical corrosion effects of metal materials and salt particles.
Composite salt spray test usually consists of three parts, salt spray test stage, moisture test stage and drying test stage.
Salt spray test phase: in general, in addition to NaCl (sodium chloride), an electrolyte containing other chemicals can also be used to simulate acid rain or other industrial corrosion.
Humet test phase: The test procedure usually requires high humidity conditions with relative humidity of 95-100%.
Drying test stage: the relative humidity of the sample drying stage is generally 30%.
Results: function must be normal, product function failure or performance parameters exceeding the design allowance is unqualified; corrosion causing any structural physical characteristics reduced by more than 25% is unqualified (including but not limited to yield strength, hardness, penetration strength, quality and bending impedance); corrosion should not occur, coating layer and matrix, and no bad phenomena affecting product appearance, such as bubbles and cracking. Non-appearance, the matrix should not appear corrosion, the corrosion depth of the coating should not exceed 5% of the surface, the corrosion area should not exceed 10%;