GH230合金的热疲劳行为  

Thermal Fatigue Behavior of Superalloy GH230

作　　者：陈石富[1] 马惠萍[1] 鞠泉[1] 赵光普[1] 

机构地区：[1]钢铁研究总院高温材料研究所,北京100083

出　　处：《钢铁研究学报》2011年第3期29-34,共6页Journal of Iron and Steel Research

基　　金：国家重点基础研究发展计划项目(2010CB631203)

摘　　要：利用开有V形缺口的平板试样,研究了GH230合金在试验最高温度分别为700、800、900和1000℃,最低温度为20℃的热循环下的热疲劳行为。研究表明,随着热疲劳试验最高温度的增加,GH230合金热疲劳裂纹扩展速率增加,但合金在不同循环温度条件下裂纹扩展长度与循环周次基本满足线性关系。通过光学显微镜和扫描电镜观察了试样的热疲劳裂纹形貌,研究了合金热疲劳损伤机制。结果表明,热疲劳主裂纹主要从V形缺口处萌生,而且主裂纹萌生和扩展方式都为穿晶断裂,同时二次裂纹也是以穿晶断裂方式扩展。当最高循环温度为9001、000℃时,合金的高温氧化进一步加速其失效。Thermal fatigue behaviors of superalloy GH230 was studied in the temperature ranges of 700, 800, 900 and 1 000℃to 20℃, using V notch plate specimens. The experimental results showed that the growth rate of the crack increased as the upper limit temperature increased, but the value of the length of the cracks was linearly dependant with the number of cycles at different test conditions. Optical microscopy （OM） and scanning electron microscopy （SEM） were used to examine the damage mechanisms of thermal fatigue. Almost all the primary faligue cracks and secondary cracks propagated intragranularly. At 900, 1 000℃ cycling, the oxidation of superalloy 230 would accelerated the failure of the specimen.

关 键 词：GH230合金 线性回归 热疲劳 主裂纹 二次裂纹 

分 类 号：TG132.32[一般工业技术—材料科学与工程]