Abstract
The flattening test,using one pair paralleled plates to flatten tube structure radially,is generally em-ployed to examine the ductility of tube used in once through steam generator (OTSG).This study fo-cuses on the stress condition and deformation mechanism analysis on the concentrated stress regions of Ti-2Al-2.5Zr alloy tube during the flattening test.Firstly,the finite element analysis was performed using the commercial software ABAQUS to determine the stress condition.Secondly,the Electron Back-Scattered Diffraction (EBSD) was implemented to observe the microstructure evolution of Ti-2Al-2.5Zr alloy.Finally,Schmid law was employed to analyze the activated deformation mechanism under condi-tion of the complex stress.It was found that the condition of the complex stress in stress concentration regions,including tension and compression regions,can be simplified into two directional stresses con-dition.In grains whose c-axis is nearly towards TD and ND,the strain is mainly accommodated by pris-matic slip,whereas in grains whose c-axis deviates about 45° from ND to TD mainly by basal slip.The{10-12} extensive twin and corresponding parent grain orientation mainly relied on the stress condition.Additionally,the intergranular twin pairs connected at common grain boundaries (GBs) with high strain compatibility were found at low angle GBs,which were activated under a combination of macro stress and strain compatibility effect.
基金项目
National Natural Science Foundation of China(51875398)
National Natural Science Foundation of China(51471116)
Sichuan Science and Technology Program(2019ZDZX0001)
Project of Nuclear Power Technology Innovation Center of Science Technology and Industry for National De-fense(HDLCXZX-2019-ZH-26)
Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Insti-tute of China()
NETL
NSTL
维普
万方数据