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Both the high temperature and particle environment at the downhole greatly aggravate the abrasive wear and shorten the service life of the fluororubber (FKM) seal seriously in drilling engineering. At present, there is less awareness of the tribological behavior of seals in such complex working conditions. In this work, the abrasive wear performance of the thermally degraded FKM seal was tested in the form of simulating the intrusion of abrasive particles into the interface. Results show that the wear of both rubber seals and metal counterparts is exacerbated. Through the analysis of the wear scar morphology and friction coefficient, it is revealed that more abrasive caves scatter on the surface due to the mechanical degradation of the FKM. These abrasion caves reduce the tendency of particles to escape from the caves and prolong the abrasive action. Furthermore, the abrasion cave alters the particle motion from sliding to rolling, which leads to more caves generated on the surface of the hard tribo-pair. These results enhance the understanding of the abrasive wear for FKM seals and hopefully contribute to the promotion of seals used in hot abrasive particle environments.

Abrasive wear resulting from the microclastic rock is a common failure phenomenon in the drilling environmentthat often limits the sealing ability and the service life of seals. In this study, the friction and wear process of uoro rubber (FKM) seals against 304 stainless steel (SS304) after one single entry of SiO 2 abrasives were investigated. The in uence of the changes in particle state on friction coe cient evolution, wear loss evolution, wear morphologies and wear mechanisms were discussed in detail. The results indicate that the presence of abrasive particles dispersed between the sealing interface clearly improves the friction performance of the seal pairs and deteriorates the wear performance of the metal counterpart. The movement and breakage of particles after one single entering into the sealing interface were obtained. And on this basis, the stable wear process can be divided into three stages. In addition, the main causes contributed to this change of wear mechanisms are the random movement and process of continuous breakdown of abrasive particles. Furthermore, the transition of the wear mechanism that clearly describes the wearing behavior of the seal pairs under these abrasive wear conditions was identi ed. The results of this study enhanced our understanding of the abrasive wear degradation of rubber seal in practical drilling applications.