【摘要】 本文在低频（3.33 Hz）载荷下,测定了重轨钢的疲劳裂纹扩展速率,采用板状单边缺口型拉-拉试样,应力比R=0.1。结果表明,攀钢U71Mn重轨钢在疲劳裂纹亚临界扩展阶段,裂纹扩展速率与应力强度因子幅度的关系: da/dN=6.19×10^-11ΔK^3.18空冷条件下冷却与经过缓冷处理的钢轨相比,在疲劳裂纹亚临界扩展阶段没有明显的差别。在疲劳裂纹扩展的第三阶段,缓冷轨的da/dN偏高。更多还原

【Abstract】 The fatigue cracking growth speed of the U71Mn heavy rail steel produced by Panzhihua Iron & Steel Company are measured by the plate specimens with unilateral notch under a low frequency 3.33 Hz load and stress ratio R=0.1, The results show that the relationship between the fatigue cracking growth speed of the steel in subcritical state and stress intensity factor amplitude can be expressed asda/dN=6.19×10^-11△K^8·13and there is not a obvious speed difference between the the air cooling and slow cooling treatment. However, it is found that the da/dN of the slow cooling steel rail is higher than that of the air cooling rail in the third stage of the fatigue cracking growth.更多还原