Biaxial Tensile Creep Damage of Mod.9Cr-1Mo Steel Using Cruciform Specimen
In this study, biaxial tensile creep tests with principal stress ratios λ of 0.0, 0.5 and 1.0 at 923K were carried out using a cruciform specimen.Here, λ is defined as λ=σy/σx where σx and σy are principal stresses in x and y directions.The λ=0.0 test corresponds to a uniaxial tension test, and that in λ =1.0 test is an equi-biaxial tension test.In the same maximum principal stress σx=l00MPa, creep rupture time in λ=0.0 is comparable to that in λ=1.0 test.In the same maximum principal stress σx=80MPa, the life in λ=0.0 is 1.5 times longer than that in λ=1.0.Creep deformation behaviour in λ=0.0 is significantly different compared with that in λ=l.0 test.Fracture surfaces of ruptured specimens at σx=100MPa were observed using a scanning electron microscope (SEM) to study the fracture morphology under biaxial stress states.Many dimples are observed in both of λ=0.0 and λ=l.0 tests.On the other hand, reduction of area and elongation in λ=1.0 test is less than those in λ=0.0 specimen.These indicate that the equi-biaxial stress reduce the ductility in biaxial creep.The maximum principal stress, Mises equivalent stress, COD stress and Huddlestons stress were applied for evaluating the creep rupture times.Mises equivalent stress was the most appropriate parameter.
Mod.9Cr-1Mo steel creep biaxial stress fracture morphology evaluation of creep rupture time
Ryosuke Itoh Takumi Hikida Fumio Ogawa Takamoto Itoh Masao Sakane Shengde Zhang
Graduate School of Science and Engineering, Ritsumeikan University Department of Mechanical Engineering, College of Ritsumeikan University 1-1-1, Nojihigashi, Kusatsu- Structure Materials Sector, Materials Science Research Laboratory, CRIEPI
国际会议
长沙
英文
60-66
2016-10-16（万方平台首次上网日期，不代表论文的发表时间）