The ASTM D6676/D6676M-21 standard specifies a test method for evaluating the cathode disbonding performance of external coatings for steel pipes in high temperature environments. This method accelerates the testing of the corrosion resistance and adhesion of coatings by simulating the use scenarios of pipes under high temperature conditions by internal heating. The specific steps include preparing the coating sample, heating it to the specified temperature, applying the cathode protection potential, and observing the disbonding of the coating. This standard applies to thermosetting, thermal plasticity, and polymer coatings and can help evaluate the long-term Stability of coatings in underground or high temperature transport media.