Corrosion on centrifuges must be addressed promptly; otherwise, it will not only pose safety risks during operation but also further exacerbate damage to the equipment. We analyze several manifestations of corrosion damage in equipment to help customers accurately assess the operating status of centrifuges.

The metal corrosion forms of centrifuges are mainly divided into two categories: uniform corrosion and local corrosion. The former is easy to detect due to its obvious surface phenomena and is clearly described in most material data, so it will not be elaborated here. Only the latter will be discussed.

Local corrosion of centrifuges occurs only in specific areas and is an extremely serious and harmful type of damage, such as pitting corrosion, crevice corrosion, intergranular corrosion, stress corrosion, and erosion-corrosion.

1、Pitting corrosion is a highly destructive corrosion phenomenon, mainly occurring in passivatable metals (such as stainless steel). Due to potential defects in local surface areas and the presence of active ions (e.g., halogen ions) in the solution that can damage the passive film, the passive film is locally destroyed, forming a galvanic couple and thus leading to pitting corrosion. After pitting corrosion forms, the centrifugal force will accelerate the dynamic process of the galvanic couple inside the pits, ensuring the persistence of pitting corrosion until perforation occurs. This is different from the pitting corrosion phenomenon under static conditions.

2、Intergranular corrosion can cause parts to lose strength and ductility, leading to brittle fracture of parts. It is a harmful damage that develops inward from the surface along grain boundaries, with no visible corrosion signs on the surface.

3、Erosion-corrosion refers to the simultaneous occurrence of wear and corrosion damage on the surface of parts.

4、Stress corrosion is damage caused by the action of a certain tensile stress in a corrosive environment. It has the following characteristics: residual tensile stress, applied tensile stress, corrosive permeating environment, and local defects.