摘要
本文研究了大型汽轮发电机转子材料26Cr2Ni4MoV钢的疲劳性能。疲劳裂纹扩展门槛值△K_(th)和扩展速率da/dn的试验结果表明.应力比R严重影响门槛值△K_(th)和扩展速率da/dn。随着应力比的增加,门槛值下降。通过应变片法测量出裂纹尖端的闭合载荷,用裂纹闭合机制合理解释了应力比R对门槛值△K_(th)扩展速率da/dn的影响,提出了门槛值和扩展速率随应力比变化规律。
The fatigue properties on steel 26Cr2Ni4MoV for large turbine generator rotor is studied in this paper.The results of the tests of fatigue crack growth threshold △K_(th) and growth rate da/dn show that threshold △K_(th) and growth rate da/dn are influnced strongly by stress. ratio R. With the increase of the stress ratio R, the threshold decreased. The closure loads of crack tips are measured by use of a strain gage method.The influences of stress ratio R on the threshold △K_(th) and growth rate da/dn can be explained by crack closure mechanism.The change law of threshold △K_(th) and growth rate da/dn with stress ratio R is given.
出处
《大电机技术》
北大核心
1991年第6期16-21,共6页
Large Electric Machine and Hydraulic Turbine
关键词
汽轮发电机
转子
疲劳性能
钢材
26Cr2Ni4MoV steel
fatigue fracture
threshold
stress ratio
crack closure
