GH4698合金高温低周疲劳性能分析

Analysis of high temperature low cycle fatigue properties for GH4698 alloy

研究了GH4698合金650℃时应变控制条件下的高温低周疲劳性能。结合疲劳试验数据,分析了合金的循环应力响应、循环应变响应及应力应变滞后回线,探讨了GH4698合金的疲劳性能。结果表明:GH4698合金在应变幅较低时具有良好的抗疲劳性能,而在较高应变幅时抗疲劳性能较差;在应变幅较低时合金会发生循环硬化和软化现象,而在应变幅较高时合金只发生循环硬化现象;随着应变幅的增加合金的循环韧性提高。

The high temperature low cycle fatigue properties of GH4698 alloy have been studied under the conditions of strain controlled at 650℃. Combining with fatigue test data, cyclic stress response, cyclic strain response and stress-strain hysteresis loop of alloy have been analyzed and the fatigue properties of GH4698 alloy have been discussed. The results show that GH4698 alloy has good anti-fatigue properties when the strain amplitude is low, while it has poor anti-fatigue properties when strain amplitude is high. The cyclic hardening and softening of alloy have been occurred when the strain amplitude is low, and only cyclic hardening has been occurred when the strain amplitude is high. The cyclic ductile of alloy has been improved with the increase of strain amplitude.