Fretting behavior of static metal seal and testing apparatus for fretting friction with low/high temperature

The low-frequency fretting behavior couples with plastic deformation under high pressure and low/high temperature during the working process of static metal seal with pressure-actuated characteristics, which affects the sealing performance and reusability. The featured specimen reflecting the geometric and physical characteristics of static metal seal was extracted, and an experiment was designed to investigate the fretting behavior. Two experimental schemes of fretting friction were proposed from the perspectives of equipment and tools, and the corresponding laboratory prototype and tools were developed. Experimental results indicated that the developed testing apparatus worked well, the expectant test can be performed, the friction coefficient rapidly increased to a stable state, and some metallic elements were transferred from soft-metal coatings of the sealing lip to the surface of the flange.