| 1. | The cyclic hardening behavior under different loading paths and different load conditions was studied
讨论了材料在不同加载路径及不同工况下的循环硬化特性。 |
| 2. | We can see bilinear behavior from the relation - ? . diagram of fatigue life and total cyclic hysteresis energy as well as the fatigue life and half - life cyclic hysteresis energy . the divergent points both reside at the strain amplitude of 0
根据合金的循环硬化和软化行为，采用分段累积的方法计算材料的总滞?能比直接用半寿命滞?能乘以循环数得到的结果更符合实测值，而用疲劳特性参数计算总滞?能误差较大。 |
| 3. | It can be noticed that both r and t specimens show initial hardening and subsequent softening at the strain amplitude higher than 0 . 8 % and cyclic softening from the beginning to fracture under strain amplitude less than 0 . 8 % at room temperature , and the cyclic flow stress was always lower in r specimen than in t specimen at the same strain range
且在相同的应变幅下， t向试样比r向试样具有更高的循环流变应力。此外，对r向及t向试样，低应变幅下呈现出循环软化现象是因为晶粒旋转导致循环软化；而在高应变幅下发生循环硬化是由于孪晶作用的结果。 |
| 4. | For the cyclic deformation under a given strain at room temperature , cyclic softening is usually displayed till to failure in the lower range of strain ; however , cyclic hardening is displayed in the early stage in the higher range of strain , subsequent cyclic softening in the later stage and till to failure
对于室温下恒应变幅的循环变形，在应变幅较低时表现为循环软化直至疲劳破坏;在应变幅较高时，循环变形的初期为循环硬化，随后是循环软化直至疲劳破坏。 |
| 5. | The alloys , which were cold - worked followed by recrystallization annealing , display cyclic softening in the range of low strain because the cyclic stress - strain curve lies below the monotonic stress - strain curve , and show cyclic hardening in the range of high strain because the cyclic stress - strain curve lies above the monotonic stress - strain curve
在低应变范围，冷加工后经再结晶退火处理的错合金的循环应力一应变曲线位于单调拉伸曲线的下方，表现为循环软化;在高应变范围则位于单调拉伸曲线的上方，表现为循环硬化。 |
| 6. | The lcf behavior of a recrystallized zircaloy - 4 plate at room temperature and 400 show that alloy has better lcf property at rt than at 400 , and cyclic hardening at 400 which could be attributed to the dynamic strain aging effects . it is noticeable that the hydrided plate has the same cyclic behavior as the above unhydrided sample at room temperature
在400下，合金表现出与常温下不同的循环特性，其循环稳定滞后回线出现锯齿状波形，且在整个疲劳过摘要程中呈现出一致循环硬化的现象，这主要是因为合金在400下发生动态应变时效效应的结果。 |
| 7. | And finally , sem has been used to characterize the fracture . the results indicate that the relationship between the fatigue lifetime and cyclic plastic strain range obeys coffm - manson relation , and the relation between the hysteresis energy ( wn ) and the plastic strain range ( p ) can be described by a power - law : wh = h pw
但在室温下， r向及t向试样具有相同的循环特性，均表现为随应变幅的不同而不同，当应变幅高于0 . 8时，呈现出先循环硬化而后循环软化直至最后断裂的现象。 |
| 8. | The last stage is a rapid softening course for all strain amplitude . further metallic phase shows : for all strain - controlled , the initial rapid cyclic hardening results from the strong interaction between precipitate strengthening phase and the dislocation ; as for strain amplitude lower than 0 . 95 % , the shearing of precipitate strengthening phase leads to the cyclic softening behavior
金相组织结构检查进一步表明，循环塑性应变作用将显著改变原始态合金中沉淀颗粒的几何形状、尺寸和分布状态，并由此改变位错与颗粒之间的交互作用行为，这一机制将对合金的循环硬化和软化起促进作用。 |
