本文在Ti-5Al-4V合金的WOL试样裂纹尖端前13mm外的区域引入氢,结果表明,20个月后试样发生了滞后开裂。离子探针断口分析表明,在裂纹前端三向应力最大的区域,氢的聚集系数远高于Li等人的热力学理论预言值exp((V_Hσ_h)/(RT))。金相和电子显微镜研究表明,在α/β相界面及α小片间界面上生成了fct和fcc结构的氢化钛沉淀。断裂正是沿着这些界面发生的。断裂力学分析表明K_(IH)≤0.46K_(IC)。基于这些实验事实,本文讨论了钛合金中氢在非均匀应力场下再分布所能达到的程度及其动力学特征;并讨论了同类实验中一些可能导致假象的因素。
Hydrogen was introduced into the region 13 mm beyond the crack tip of a modified WOL specimen of Ti alloy Ti-SAl-4V. The delay cracking was growing up in the specimen about 20 months later. The results of an ion probe microanalysis showed that the hydrogen concentration coefficient at the maximum of triaxial stress in the front of crack tip is much greater than the theoretical value exp((?)_Hσ_h/RT) predicted by thermodynamics. Observations by metallography and TEM proved that the titanium hydrides of fct and fcc lattice precipitate at α/β interphase boundaries and interfaces between a facets, The delay cracking takes place just along these interfaces. An analysis by fracture mechanics indicates that K_(IH)≤0.46K_(IC). Based upon the above mentioned experimental results, discussions were made on the extent of the hydrogen redistribution in Ti alloy under a stress gradient, on the kinetic feature of this process, as well as on the possible causes of falsity in similar experiments.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | |
| [7] | |
| [8] | |
| [9] | |
| [10] | |
| [11] | |
| [12] | |
| [13] | |
| [14] | |
| [15] | |
| [16] | |
| [17] | |
| [18] | |
| [19] | |
| [20] | |
| [21] | |
| [22] | |
| [23] | |
| [24] | |
| [25] | |
| [26] | |
| [27] | |
| [28] | |
| [29] | |
| [30] | |
| [31] | |
| [32] | |
| [33] | |
| [34] | |
| [35] | |
| [36] | |
| [37] | |
| [38] | |
| [39] | |
| [40] |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%