十字型試験片を用いた高温多軸クリープ疲労

抄録

This paper describes the creep-fatigue damage evaluation of SUS 304 stainless steel in wide ranges of multiaxial stress and strain states. Low cycle fatigue and creep-fatigue tests were carried out using a cruciform specimen in a full range of strain biaxiality including equi-biaxial tension/compression at 823K and 873K. Mises' equivalent strain, maximum principal strain, the equivalent strain based on crack opening displacement (COD) and Γ^*-parameter were applied to the experimental low cycle fatigue data. The latter two strain parameters gave a better correlation than the former two strain parameters. The discussion on the correlation of the biaxial creep rupture data was briefly made and the equivalent stress based on COD was the most suitable stress parameter correlating the biaxial creep rupture data. Creep-fatigue damage was evaluated based on the equivalent strain and stress based on COD. The creep-fatigue damage evaluated fell around a line of unity in value, which indicates that the linear damage rule holds in the biaxial creep-fatigue.