测量了A537钢在恒ΔK控制下单次拉伸超载对腐蚀疲劳裂纹扩展的影响,研究了阴极极化及自腐蚀条件下材料在3.5％NaCl水溶液中的超载延迟扩展规律与特点。结果表明:单次拉伸超载裂纹扩展延迟效应的作用距离大于塑性区尺寸。空气中与阴极极化条件下,超载后裂纹扩展过程由超载扩展、减速扩展与恢复三阶段组成,而自腐蚀条件下只有减速扩展与恢复两个阶段。与空气中的结果相比,阴极极化与自腐蚀条件下的裂纹扩展延迟幅度与延迟距离均明显减小。分析表明,塑性诱发裂纹闭合在腐蚀条件下的变化是造成超载后裂纹扩展规律变化的主要原因之一。
The effect of single overload on corrosion fatigue crack growth rate under constant △K control was studied for A537 steel in air and in 3.5% NaCl solution at a cathodic potential of -1400mV (SCE) and under free corrosion condition. The results showed that the retarding propagation distance of crack was longer than the plastic zone size at the crack tip. Either in air or in 3.5% NaCl at the cathodic potential, the crack growth process following single overloading consisted of three stages: crack extension due to overload, deceleration of crack growth and resumption of crack growth rate. However, the crack extension stage was not observed for the specimen tested in the solution under free corrosion condition. Both the retarding propagation distance and retarding degree for corrosion fatigue crack propagation in the solution were smaller than those for fatigue crack propagation in air. The theoretical analysis indicated that the crack closure effect was mainly responsible for the change of crack growth retardation in corrosion fatigue.
参考文献
| [1] |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%