摘要
The effect of phosphorus on mechanical properties and thermal stability of fine-grained GH761 alloy has been investigated.The results show that,when the content of phosphorus is in the range of 0.0007-0.040,there are no significant effects on the tensile properties.Phosphorus strongly affects the stress rupture life.The content of 0.023 P results in the longest life in this experiment.Compared with that of the alloy with 0.0007 P,the life is increased more than 2 times in the alloy with 0.023 P.After ageing at 700℃ for 1000 h,the life reduced to some extent.However,phosphorus exhibits the similar effect on the life as before ageing.The tensile properties of the alloy are not influenced by long term ageing obviously.The present results suggested that the optimum content of phosphorus is 0.023.The phosphorus with this content can optimize the precipitates at the grain boundaries and prevent the excessive growth of the precipitates.The combining mechanical properties of GH761 alloy can be largely improved by phosphorus addition combined with grain refinement.
基金
supported by the National Natural Science Foundation of China under the contracts of Nos.50271072 & 50471083
