Technical note High-cycle fatigue crack initiation and propagation behaviour of high-strength sprin steel wires
Technical note High-cycle fatigue crack initiation and propagation behaviour of high-strength sprin steel wires
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DOI：
10.1046/j.1460-2695.1999.t01-1-00184.x
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发表时间：
1999-08
影响因子：
3.7
通讯作者：
Q. Wang;J. Berard;S. Rathery;C. Bathias
中科院分区：
文献类型：
--
作者：
Q. Wang;J. Berard;S. Rathery;C. Bathias
利用超声疲劳试验和分析技术，对高强度弹簧钢丝的高周疲劳行为进行了表征。采用两种感应回火超高强度弹簧钢丝，直径6.5 mm，抗拉强度1800 Mpa。在载荷比R=-1条件下，测定了钢丝在106~109次循环范围内的疲劳强度。试验结果表明，疲劳断裂可超过107个循环。对于铬钒弹簧丝，在106次循环后，应力-寿命(S-N)曲线在最大应力为800MPa时变为水平，但在高循环次数(>；106次)下，S-N曲线继续下降，并且不表现出疲劳极限，而疲劳极限更准确地描述为给定循环次数的疲劳强度。用扫描电子显微镜(SEM)研究了裂纹的萌生和扩展行为。为了更好地了解和预测高周疲劳寿命，从裂纹的萌生和扩展方面开发了实验和分析技术。结果表明，在高周疲劳条件下，裂纹萌生在疲劳寿命中所占比例超过90%。
An attempt has been made to characterize high-cycle fatigue behaviour of high-strength spring steel wire by means of an ultrasonic fatigue test and analytical techniques. Two kinds of induction-tempered ultra-high-strength spring steel wire of 6.5 mm in diameter with a tensile strength of 1800 MPa were used in this investigation. The fatigue strength of the steel wires between 10 6 and 10 9 cycles was determined at a load ratio R = -1. The experimental results show that fatigue rupture can occur beyond 10 7 cycles. For Cr-V spring wire, the stress-life (S-N) curve becomes horizontal at a maximum stress of 800 MPa after 10 6 cycles, but the S-N curve of the Cr-Si steel continues to drop at a high number of cycles (> 10 6 cycles) and does not exhibit a fatigue limit, which is more correctly described by a fatigue strength at a given number of cycles. By using scanning electron microscopy (SEM), the crack initiation and propagation behaviour have been examined. Experimental and analytical techniques were developed to better understand and predict high-cycle fatigue life in terms of crack initiation and propagation. The results show that the portion of fatigue life attributed to crack initiation is more than 90% in the high-cycle regime for the steels studied in this investigation.