摘要
以2 MW风力机叶片42CrMoA高强连接螺栓材料为研究对象,用FLPL微机控制扭转疲劳试验机开展不同应力水平下的扭转疲劳试验。结果表明:42CrMoA材料的扭转疲劳寿命对施加的扭应力水平异常敏感,施加在高强连接螺栓上的安装扭矩不应超过理论值的1.2倍。在1.2倍理论扭矩(490 MPa)下,42CrMoA钢螺栓材料表现出良好的扭转疲劳性能,扭转疲劳寿命达10;周以上,在1.2~1.4倍理论扭矩(490~570 MPa)下,螺栓材料的扭转疲劳寿命骤减,仅为15446周;在扭转疲劳过程中,42CrMoA钢材料的组织结构由正常均匀弥散的一级回火索氏体演变为块状及网状铁素体结合的不完全回火索氏体,使材料强度降低;扭转疲劳断裂为典型纯滑移型断裂,疲劳裂纹萌生于光滑试样表面,向试样内部衍生并在扭转疲劳过程中形成二次裂纹;42CrMoA钢扭转疲劳断裂类型在不同扭循环应力下基本为NF+LS→LS型顺序转变。
The 42CrMoA high-strength bolt material for a 2 MW wind turbine blade was taken as the research object,the torsion fatigue test of the bolt material under different stress levels were carried out by using the FLPL microcomputer controlled torsion fatigue test machine.The results show that the torsion fatigue life of 42CrMoA material is extremely sensitive to the level of torsion stress applied,the mounting torque applied to the high-strength connecting bolt should not be exceed 1.2 times of the theoretical value.In the range of 1.2 times the theoretical torque(490 MPa),the 42CrMoA steel bolt material shows a good torsion fatigue performance,and the torsion fatigue life reaches more than 106cycles.In the range of 1.2 times to 1.4 times the theoretical torque(490-570 MPa),the torsion fatigue life of bolt material is reduced to only 15446 cycles.During the process of torsion fatigue,the microstructure of 42CrMoA steel changes from normal and uniformly dispersed first stage of tempered sorrotenite to incomplete tempered sorrotenite combined with massive and reticular ferrite,which reduces the material strength.The torsion fatigue fracture is a typical pure slip fracture.The crack initiates from the surface of the smooth specimen and propagates to the interior,and the secondary cracks forms during the fatigue propagation process.The torsion fatigue fracture type of 42CrMoA steel basically follows the order transformation of NF+LS→LS under different torsion cyclic stresses.
作者
蒲珉
何建军
揭军
陈标
曾子竞
程庆阳
PU Min;HE Jianjun;JIE Jun;CHEN Biao;ZENG Zijing;CHENG Qingyang(School of Energy and Power Engineering,Changsha University of Science and Technology,Changsha 410114,China;Longyuan Jiangyong Wind Power Generation Co.Ltd.,of CHN Energy Group,Changsha 410000,China;Xian Zhongke Qihang Monitoring and Control Technology Co.Ltd.,Xi'an 712000,China)
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2022年第3期119-124,共6页
Ordnance Material Science and Engineering
基金
国家能源集团科技创新项目(HJLFD-QTHT-2020-08)
长沙理工大学研究生科研创新项目(CX2020SS63)。
