Papers by Author: Wei Ming Sun

Abstract: The design of pressurized components at elevated temperature is limited by available mechanical properties that often do not span appropriate range of stress, time, strain and temperature. To improve the design process, a new approach based on short-time stress relaxation test (SRT) is introduced in steel tensile creep analysis. The experiments are implemented using SRT and tested for creep properties of 12Cr1MoVG steel at 560 °C. The results of creep curves agree well with the traditional constant load creep test data. The possibility to apply SRT approach is shown promising in the design of the pressurized component at elevated temperature.

Abstract: The effect of contact pressure on fretting fatigue in quenched and tempered 45-carbon steel is studied. With an increase in contact pressure, fretting fatigue life is decreased quickly at low contact pressures; however it almost unchanged at high contact pressures. With an increase in cyclic stress amplitude, fretting fatigue life decreased. In the test, concavity is formed at the fretted area accompanying wear. The main crack is initiated at the outer edge corner of the concavity at high contact pressures, and initiated at the middle portion of the fretted area at low contact pressures.