Gleeble-1500D热力模拟试验机对喷射成形热等静压GH742y高温合金在变形温度1050℃~1140℃，应变速率0.01s-1~10.0s-1，工程应变量50%的条件下进行热压缩实验，利用实验数据建立了合金的热加工图和热激活能图，对变形过程中组织演化进行了研究。结果表明，热等静压并没有使喷射成形合金晶粒尺寸明显长大。真应力-应变曲线中出现了屈服降落现象，这是由于变形过程中位错运动和密度变化造成的；合金热加工图中失稳区在1050℃～1110℃,应变速率为0.01s-1区间，在1110℃~1140℃，高应变速率1.0 s-1~10.0s-1区间功率耗散值出现最大值；激活能图中在1140℃，应变速率1.0~10.0s-1区间出现一平台区。结合试样组织变化情况，在变形温度1110℃~1140℃或应变速率1.0 s-1～10.0s-1，变形量为50％的条件下，可得到完全再结晶组织。因此喷射成形GH742y合金的适合变形条件为1110℃~1140℃，1.0 s-1～10.0s-1，变形程度为50％。
The hot compression testing of spray formed plus hot isostatic pressing (HIPing) GH742y superalloy was conducted by Gleeble-1500D thermal mechanical simulator at testing temperatures in the range of 1050℃ to 1140℃, and strain rates in the range of 0.01 s-1~10.0s-1 with engineering strain 50%. The processing map and activation energy map of alloy were established by testing data, and microstructure evolution of deformed samples was also examined. The results show that the grain size of spray formed alloy does not significantly increase after HIPing. Due to the variation of dislocation movement and density in deformation, the yield drop was observed, but without yield drop at low deforming temperature. Processing map and activation energy map obtained at the strain of 0.69 indicate that the instability domain is observed at the temperature of 1050℃～1110℃ and strain rate of 0.01s-1, and the highest efficiency of power dissipation (η) is obtained at the temperature of 1110℃~1140℃ and the strain rate of 1.0 s-1~10.0s-1, and platform region was also observed at the temperature of 1140℃ and the strain rate of 1.0~10.0s-1. So, the optimum conditions for thermomechanical processing correspond to the η maximum region and activation energy platform region. The full dynamic recrystallization (DRX) microstructure occurred at the optimum condition.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | |
| [7] | |
| [8] | |
| [9] | |
| [10] | |
| [11] | |
| [12] | |
| [13] | |
| [14] | |
| [15] | |
| [16] | |
| [17] | |
| [18] | |
| [19] |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%