摘要
针对符合转子制造技术规范的25Cr2MoVA钢、25Cr2Mo1VA钢和40Cr钢进行了高周疲劳试验,基于无疲劳极限半对数曲线模型拟合得到了三种钢的P-S-N曲线,并分析了疲劳断口形貌。结果表明:疲劳循环108周次时,25Cr2MoVA钢、25Cr2Mo1VA钢和40Cr钢疲劳极限分别为465,455,460MPa;随着应力降低,三种钢的疲劳寿命均持续增加,P-S-N曲线下降的趋势变缓,但未出现显著的水平平台;三种钢的疲劳裂纹均萌生于材料表面,裂纹扩展呈放射状,25Cr2MoVA钢和25Cr2Mo1VA钢瞬断区具有韧窝特征,它们的韧性优于40Cr钢的;在遭受次同步振荡时,25Cr2MoVA钢转子的安全可靠性最高。
The high-cycle fatigue experiments were carried out for 25Cr2MoVA steel, 25Cr2Mo1VA steel and 40 Cr steel, which complied with the manufacture of rotor＇s technical specifi cations. The P-S-N curves of three kinds of steel were fi tted based on the unlimited fatigue＇s semi-logarithmic model and the morphology of fatigue fracture was analyzed. The results show that the fatigue limits of strength of 25Cr2MoVA steel, 25Cr2Mo1 VA steel and 40 Cr steel were 465 MPa, 455 MPa and 460 MPa, respectively, when the fatigue cycle was 108 times. With the decrease of stress the fatigue lives of three kinds of steel increased continuously, and the P-S-N curves showed a slow trend of decline, but there was no signifi cant platforms. For 25Cr2 Mo VA steel, 25Cr2Mo1 VA steel and 40 Cr steel, the crack initiated from the material surface and propagated radially. The dimple feature was showed in the transient fracture zone for 25Cr2 Mo VA steel and 25Cr2Mo1 VA steel, whose toughness was all better than that of 40 Cr steel. The rotor with 25Cr2 Mo VA steel was safer and more reliable than the other two materials when they suffered subsynchronous oscillation
出处
《机械工程材料》
CAS
CSCD
北大核心
2015年第6期57-61,66,共6页
Materials For Mechanical Engineering
关键词
转子
疲劳极限
裂纹源
次同步振荡
rotor
fatigue limit
crack source
subsynchronous oscillation
作者简介
王红涛（1977-），男，河北开封人，讲师，硕士。
