GB/T 9989.3 - 2015 is the third part of the standard for the determination of chemical erosion resistance of enamels, focusing on the determination of alkali solution erosion of enamels in hexagonal containers. The standard clearly states the test equipment, that is, the specific hexagonal container, and specifies the sample preparation process. Operationally, the enamel sample is placed in a hexagonal container containing alkali solution and tested under specified conditions. By observing the erosion of the sample, the alkali resistance is assessed according to the established standard. This standard provides a method for accurately evaluating the corrosion resistance of enamels in alkaline environments, and is of great significance for the mass control of enamel products in alkaline environments.