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Since there are many factors that affect metal corrosion, salt spray resistance alone cannot replace resistance to other media; therefore, the test results obtained under this standard cannot serve as a direct guide to the corrosion resistance of the tested materials in all application environments. At the same time, the performance of various materials in tests cannot serve as a direct guide to their corrosion resistance in use. Salt spray aging test machine Nevertheless, the method specified in this standard can still be used as a way to determine whether the material under test possesses corrosion-resistant properties or not. Referenced Standards The provisions contained in the following standards become part of this standard by being referenced herein. At the time of publication of this standard, all versions listed are valid; all standards are subject to revision, and those using this standard should consider the possibility of using the latest versions of the relevant standards. GB 5213—85 Cold-rolled thin steel sheets and strips for deep drawing; GB 6461—86 Metal coatings – Rating of electroplated specimens after corrosion testing on cathodic substrates (eqv ISO 4540:1980); GB 12335—90 Metal coatings – Rating of specimens after corrosion testing on anodic substrates (eqv ISO 8403:1991); GB/T 9798—1997 Metal coatings – Nickel electrodeposited layers (eqv ISO 1458:1988); ISO 6372-1:1989 Nickel and nickel alloys – Terms and definitions – Part 1: Materials. Test conditions: 1. The temperature in the salt spray chambers for the neutral salt spray test and the acetate salt spray test is 35°C ± 2°C. The temperature in the salt spray chamber for the copper-accelerated acetate salt spray test is 50°C ± 2°C. During the testing process, the temperature fluctuations throughout the salt spray chamber should be as minimal as possible. - 2. The test samples were placed in the salt spray chamber as planned, and the test was only commenced after confirming that the salt spray collection rate and conditions were within the specified range. 3. The rate of salt spray deposition: after 24 hours of spraying, it is 1–2 ml/h per 80 cm2 area ； The sodium chloride concentration is 50 g/L ± 5 g/L ； The pH range is: 6.5–7.2 for the neutral salt spray test, 3.1–3.3 for the acetate salt spray test, and 3.1–3.3 for the copper-accelerated acetate salt spray test. 4. Used spray solutions must not be used again. 5. The temperature and pressure during the test should remain stable within the specified range. Treatment of the specimens after testing: After the test is completed, the specimens are removed. To reduce the shedding of corrosion products, they are left to dry naturally in a room for 0.5–1 hour before cleaning. Afterwards, they are gently washed with clean running water at a temperature not exceeding 40°C to remove any residual salt spray solution from their surface, and then dried immediately with a hair dryer. Evaluation of test results: The criteria for evaluating test results should generally be established by the standards for the materials or products being tested. For general tests, only the following aspects need to be considered: a) appearance after testing ； b) Appearance after removal of surface corrosion products ； C) The distribution and quantity of corrosion defects such as pitting, cracks, bubbles, etc., can be evaluated using the methods specified in Appendix C of GB 6461, GB12335, and GB/T 9798—1997 (eqv ISO 1462:1973) ； d) Time when corrosion begins to appear ； e) Weight change ； f) Microscopic observation ； g) Changes in mechanical properties.