Study on the Degradation Evolution of GIS O-Rings Under Multi-Factor Accelerated Aging Test

O-ring is the key part of SF 6 gas seal for GIS equipment, and the multi-factor accelerated aging test is an important method to study the evolution of the mechanical properties with aging time. In this paper, the three-factor accelerated aging test of thermal, compression, and pressured SF 6 (TCS), as well as the traditional two-factor accelerated aging test of thermal and compression (TC) were performed on the GIS seal ring samples. The aging temperatures were 90°C, 105°C and 120°C, and the compression ratios were 20%, 25%, 30%. The test device was filled with 0.3 MPa SF 6 gas, and the aging time ranged from 0 to 122 days. After the aging, the compression set (CS) were tested. The test results showed that the evolution of CS under TCS could be modelled by exponential functions, and the degradation rate was slower than that of TC.