Creep behavior of Super304H austenitic steel has been investigated at elevated temperatures of 923-973 K and at applied stress of 190-210 MPa. The results show that the apparent stress exponent and activation energy i...Creep behavior of Super304H austenitic steel has been investigated at elevated temperatures of 923-973 K and at applied stress of 190-210 MPa. The results show that the apparent stress exponent and activation energy in the creep deformation range from 16.2 to 27.4 and from 602.1 to 769.3 kJ/mol at different temperatures, respectively. These high values imply the presence of a threshold stress due to an interaction between the dislocations and Cu-rich precipitates during creep deformation. The creep mechanism is associated with the dislocation climbing governed by the matrix lattice diffusion. The origin of the threshold stress is mainly attributed to the coherency strain induced in the matrix by Cu-rich precipitates. The theoretically estimated threshold stresses from Cu-rich precipitates agree reasonably with the experi- mental results.展开更多
To the Editor: Stereotyped behavior refers to a series of behaviors with a high frequency and no obvious purpose and meaning. It also includes narrow interest and difficulty in accepting changes in things. In addition...To the Editor: Stereotyped behavior refers to a series of behaviors with a high frequency and no obvious purpose and meaning. It also includes narrow interest and difficulty in accepting changes in things. In addition to autism spectrum disorder (ASD), stereotyped behavior also exists in various neurodevelopmental disorders, such as Tourette syndrome, Fragile X syndrome, Prader-Willi syndrome, obsessive-compulsive disorder, and many other diseases, which are considered to be related to dysfunction of the striatum.展开更多
基金financially supported by the National Natural Science Foundation of China(No.50931003)the Shanghai Science and Technology Committee(No.13dz2260300)
文摘Creep behavior of Super304H austenitic steel has been investigated at elevated temperatures of 923-973 K and at applied stress of 190-210 MPa. The results show that the apparent stress exponent and activation energy in the creep deformation range from 16.2 to 27.4 and from 602.1 to 769.3 kJ/mol at different temperatures, respectively. These high values imply the presence of a threshold stress due to an interaction between the dislocations and Cu-rich precipitates during creep deformation. The creep mechanism is associated with the dislocation climbing governed by the matrix lattice diffusion. The origin of the threshold stress is mainly attributed to the coherency strain induced in the matrix by Cu-rich precipitates. The theoretically estimated threshold stresses from Cu-rich precipitates agree reasonably with the experi- mental results.
文摘To the Editor: Stereotyped behavior refers to a series of behaviors with a high frequency and no obvious purpose and meaning. It also includes narrow interest and difficulty in accepting changes in things. In addition to autism spectrum disorder (ASD), stereotyped behavior also exists in various neurodevelopmental disorders, such as Tourette syndrome, Fragile X syndrome, Prader-Willi syndrome, obsessive-compulsive disorder, and many other diseases, which are considered to be related to dysfunction of the striatum.
