晶界碳化物对GH864合金裂纹扩展速率的影响

Effect of the Grain Boundary Carbide on the Crack Propagation Rates of GH864 Alloy

摘要:

研究不同热处理制度后晶界碳化物对GH864合金650 ℃裂纹扩展速率的影响。结果表明：不同热处理制度处理后GH864合金晶界碳化物形态逐渐演化：颗粒较少→断续状→连续状→项链状→包膜状。晶界碳化物不断析出起到强化晶界的作用，使裂纹扩展速率降低。得到GH864合金晶界碳化物连续系数fc与裂纹扩展速率的变化趋势图。当晶界碳化物连续系数fc小于1时，抗裂纹扩展能力随晶界碳化物尺寸的增加而增加。建立裂纹扩展速率与晶粒尺寸和晶界碳化物的综合作用的关联性，晶粒尺寸和晶界碳化物之间相互作用存在最低点，抗裂纹扩展能力最佳

Abstract:

The effects of grain boundary carbide on crack propagation behavior of GH864 alloy were studied at 650 oC after different heat-treatment. The results indicate that the pattern of grain boundary carbide of GH864 alloy is gradually evolved after different heat-treatment, i.e. little particle→discontinued→continued→necklace→closed. The precipitation of grain boundary carbide strengthens the grain boundary and decreases the crack growth rate. The change tendency was concluded between the grain boundary carbide continuous factor and the crack growth rate. When the grain boundary carbide continuous factor is below 1, the crack propagation resistance increases with increasing the size of grain boundary carbide and grain size. The comprehensive interaction effect between the grain size and grain boundary carbide was also concluded. The optimum crack propagation resistance may exist when there is the lowest point in the interaction effect between the grain size and grain boundary carbide