采用不同温度进行中间热处理,以改变晶界沉淀相的类型、形态和数量。测定了室温和-196℃的冲击韧性。用扫描电镜和电子显微镜观察了冲击断口和断口萃取复型。结果表明,当晶界二次TiC沉淀很少或TiC以薄片状密集分布于晶界时,合金具有缺口敏感性;TiC或Laves相以较大而厚的片状沿晶析出,或以颗粒状分布于晶界时,合金无缺口敏感性. 晶界TiC沉淀很少或呈颗粒状分布时,合金冲击韧性高,呈穿晶韧性断裂;TiC或Laves相呈片状沿晶分布时,冲击值低,冲击试样断口表现为沿晶脆性断裂。
The intermediate heat treatment under different temperatures was adopted tomodify the type, shape and amount of the grain boundary precipitate phases. Theimpact toughness of the alloy after intermediate heat treatmeni was evaluated atroom temperature and -196℃. Observations under SEM and TEM were carriedout on the impact fracture and its extraction replica. Resutlts showed that thesecondary TiC densely precipitates along grain boundary as thin flakes whichare exactly like a thin brittle coating over grain, but on the other hand, thegrain boundary TiC precipitates in less amount, and the notch sensitivity forstress rupture is found in the alloy. When the TiC or Laves-phase precipitatedas coarser and thicker flakes or as granules along grain boundary, the alloy hasno notch sensitivity. However, when the grain boundary TiC precipitated lessor distributed as granule, the alloy is improved over its impact toughness andthe impact fracture is transgranular. When the TiC or Laves-phase as-flakes dis-tributed along grain boundary, the impact toughness of the alloy is worsened andthe impact fracture is intergranular.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | |
| [7] | |
| [8] | |
| [9] | |
| [10] | |
| [11] | |
| [12] | |
| [13] | |
| [14] | |
| [15] |
- 下载量(0)
- 访问量(335)
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%