P含量对细晶GH761合金力学性能的影响

EFFECT OF P CONTENT ON MECHANICAL PROPERTIES OF FINE-GRAINED GH761 ALLOY

研究了P含量对细晶GH761合金组织和性能的影响.结果表明:P含量在0.0007%0.040%(质量分数)之间时,对合金的室温和650℃拉伸性能影响不大,但显著影响650℃/690 MPa下的持久性能和700℃/550 MPa下的蠕变性能.P含量在0.023%左右可成倍提高细晶合金的持久寿命,降低蠕变速率.细晶化和P微合金化相结合的方法可以在显著提高合金拉伸强度和塑性的同时,保持合金优良的持久和蠕变性能,从而全面优化合金的综合性能.

Effect of P content on the microstructure and mechanical properties of fine-grained GH761 alloy was studied. The results showed that no obvious effect on the tensile properties of fine grained GH761 alloy was observed when P content in GH761 alloy was below 0.040% （mass fraction）. However, P influenced the stress rupture and creep properties greatly. The peak value of the life at 650 ~C and 690 MPa appeared around 0.023%P. In comparison with that of the alloy with 0.0007%P, the life increased more than 2 times. At the same time, the creep rate of the alloy with 0.023%P is also the lowest in all of alloys. P is beneficial to the mechanical properties of fine-grained GH761 alloy by improving the precipitation at grain boundaries and impeding the disclocation movement. The overall properties of GH761 alloy can be improved by grain refining and appropriate amount of P addition.