Effect of the Solution Treatment on the Crack Propagation Rates of GH864 Alloy

Abstract:

The effect of the solution treatment on the crack growth rate regularity of GH864 alloy was studied at 650 oC. The results indicated that the crack growth rate firstly decreases and then increases with increasing grain size and solution temperature. The relationship between grain size and the crack growth rate was fitted according to milt-group test data. It is predicted that the crack growth resistance may have an optical point when the grain size reaches 100 μm. The relationship between solution temperature and the crack growth rate of GH864 alloy was concluded. The crack growth rate regularity of GH864 alloy is divided into five areas by different solution temperatures. The crack growth rate is decreased with increasing the solution temperature when the solution temperature is below 1080 oC, and the lowest occurs at the solution temperature 1080 oC while the rate is increased with increasing the solution temperature when the solution temperature is higher than 1080 oC. The crack growth resistance may be obtained by precisely controlling solution temperature and grain size.

Key words:GH864 alloy; crack growth rate; grain size; solution temperature