摘要
采用疲劳实验和回归分析相结合的方法,研究了S135钻杆钢在拉扭复合加载条件下的疲劳行为,并对疲劳断口进行了微观分析。结果表明:当τa/σeq=0.7时,由拉扭应力幅对应的当量应力表示的疲劳寿命公式可很好地描述S135钻杆钢的拉扭疲劳寿命规律;疲劳断口由疲劳源区、疲劳裂纹稳定扩展区和快速瞬断区组成,疲劳裂纹从试样表面萌生,并向试样内部扩展,且常为多疲劳源,不同疲劳源断口的连接和复合加载形成所谓的"屋脊"状特征;拉扭疲劳断裂试样裂纹源区的微观断口特征为明显的河流花样,裂纹扩展区的微观断口特征为疲劳条带与涟波状花样。
Biaxial fatigue behavior under combined axial and torsional loading for $135 drill pipe steel was investigated by means of fatigue tests and data regression analysis methods, and the fracture sur- faces were observed through scanning electron microscopy. The results show that when is 0.7 the fatigue life regulation of 8135 drill pipe steel under combined axial and torsional loading can be re- presented well by the fatigue life equation, which is expressed by equivalent stress of tension-torsion stress amplitude. The fracture surfaces are mainly divided into three regions such as the crack initia- tion, steady crack propagation and instantaneous fracture. Fatigue cracks mainly initiate at the speci- men surface and propagate rapidly in specimen. Fatigue cracks are multiple source and the so-called ridge patterns were formed by connecti ture surfaces are characteristic of rive characteristic of fatigue striation and ri ng the different fatigue source and comb k initiation region, th ined loading. The frac- e fracture surfaces are crack propagation region.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2013年第1期40-44,共5页
Journal of Materials Engineering
关键词
S135钻杆钢
双轴疲劳
同相位
拉扭复合加载
断口
S13 5 drill pipe steel biaxial fatigue in-phase combined axial-torsional loading fracture
