An experimental study of cracking processes generated in a contact subjected to fretting-fatigue loading under CO_2 corrosive seawater environment

摘要

In order to analyze the combined interaction between fretting contact and corrosion regarding the fretting-fatigue endurance, an innovative fretting-fatigue-corrosion (FFC) test machine has been developed: a corrosive cell with a CO_2-saturated solution was integrated in a hydraulic fretting-fatigue test machine in order to study the fretting-fatigue loading of an industrial steel under a controlled corrosive environment. The influence of the tangential force amplitude and the frequency on the cracking nucleation has been analyzed by carrying out fretting-fatigue tests in dry and wet conditions. By dividing the friction coefficient by a factor two, seawater considerably reduced the contact fretting stressing compared to dry conditions. However, investigation of lower loading frequency suggests that corrosion mechanisms increase the cracking extension. A global description of seawater condition regarding an aqueous CO_2 system corrosion and friction behavior is introduced taking into consideration the effect of loading frequency and fretting displacement in the interface.