Why does the rear expansion bottom anchor rust? The bottom enlargement of the post-expanded anchor bolt is also a metal product, but its chemical stability is good, but when its surface is polluted, such as oil, dust, acid, alkali, salt, etc. attached to the surface of the workpiece, it is converted into corrosive medium. Certain conditions can react with certain parts of the rear bottom enlargement, resulting in chemical corrosion and rust, so mechanical bottom enlargement fasteners also require anti-oxidative treatment.
The main reason for the expansion of the bottom of the post-expanded anchor is that there is a film on its surface to prevent it from being oxidized and corroded. Of course, if it disappears and is destroyed for some reason, it will lose its protection and continue to be corroded.
The rust of the rear reaming bolt may have the following reasons: First, the surface of the bottom of the reaming hole is prone to dust or other metal particles. If the surrounding environment is relatively humid, it will react and destroy the protective film. Second, the surface of the bottom of the reaming hole is covered with some noodle soup or other impurities, which form organic acids, which will damage the metal for a long time. Third, there are impurities in its surface, polluted air, or encounter special circumstances: nitric acid, condensate, etc., which will cause the protection of the enlarged surface of the rear bottom to fail.