Numerical Prediction of Creep Crack Growth Rate in Cr-Mo-V Steel for Specimens with Different Constraints
The creep crack growth rate in Cr-Mo-V steel has been numerically predicted for specimens with different constraints for a wide range of C* by using stress dependent creep model and ductility, and the simulated da/dt-C* curves were compared and analyzed with experimental data.The results show that the simulated da/dt-C* curves agree well with experimental data.At low and transition C* regions, the crack-tip constraint has obvious effect on CCG rates, while at high C* region it almost has no effect.With increasing constraint, the CCG rates and transition region size on da/dt-C* curves increase due to higher stress traxiality ahead of crack tip and stress-regime dependent creep ductility.If the extrapolation CCG rate data of standard high constraint CT specimen from high C* region (above the turning point 2) or from transition C* region are used in life assessments of the components with various constraints at low C* region (below the turning point 1), the non-conservative or excessive conservative results may be produced.Therefore, the CCG rate data for considering constraint effect should be obtained for a wide range of C* by long-term laboratory tests or numerical predictions using the stress dependent creep model and ductility.
constraint creep crack growth rate creep ductility C* region finite element
Jingwei Zhang Guozhen Wang Fu-Zhen Xuan Shan-Tung Tu
Key Laboratory of Pressurized System and Safety,Ministry of Education,East China University of Science and Technology,Shanghai 200237,China
国际会议
2014 International Symposium on Structural Integrity,ISSI2014(2014国际结构完整性学术会议)
兰州
英文
243-250
2014-08-20（万方平台首次上网日期，不代表论文的发表时间）