The rust tendency of stud bolt connection fastener is directly related to its body material and surface protection process. The electrochemical activity of the metal matrix determines the initial rate of the oxidation reaction. When carbon steel products are exposed to a humid environment without protection, the continuous contact between iron and oxygen and electrolyte will induce galvanic corrosion. The alloy components of stainless steel inhibit the oxidation process by forming a passivation film, but its protective effectiveness is restricted by the integrity of the intergranular structure.
The surface treatment process has a key influence on the rust process of stud bolt connection fastener. The hot-dip coating delays the oxidation reaction by isolating the contact path between the base metal and the environmental medium. The difference in coverage uniformity of mechanical plating technology may lead to the generation of local protection weaknesses, which become the priority area for corrosion initiation.
The risk of stress corrosion cracking of stud bolt connection fastener is particularly significant in the threaded meshing part under continuous load, and the alternating stress increases the probability of fatigue crack propagation of the protective layer. When salt spray deposition in the marine atmospheric environment coexists with sulfide substances in industrial pollution areas, synergistic corrosion effects may be induced.
The application of sealant changes the microenvironmental conditions of the stud bolt connection fastener connection parts, and reduces the migration rate of active corrosion factors by blocking the oxygen and water transmission channels. The effect of anti-corrosion coating re-coating during the maintenance period of stud bolt connection fastener depends on the surface treatment quality of the old coating, and the degree of removal of residual oxidation products affects the adhesion of the new protective layer. The difference in electrochemical properties of gaskets of different materials may lead to potential difference corrosion between contact surfaces. This hidden problem often gradually appears over time.
