This standard specifies a natural exposure test method for evaluating the stress corrosion cracking resistance of metals and their alloys in atmospheric environments. The method involves long-term exposure of specimens subjected to constant or cyclic stress in real outdoor settings to assess their susceptibility to failure under the combined effects of natural environments (such as industrial atmospheres, marine atmospheres, etc.) and sustained stress. The standard details the setup of test conditions, preparation of various types of stress-loaded specimens (such as U-bend specimens, C-ring specimens, and tensile specimens), specific exposure test procedures, and methods for post-test data processing and result analysis. This method provides critical outdoor empirical evidence for material selection and durability assessment in fields such as metallurgy, machinery, aerospace, and automotive industries.