加载载荷对ADB610钢疲劳裂纹扩展性能的影响研究

针对ADB610新型低碳贝氏体钢,采取紧凑拉伸试样、恒幅加载方式,在应力比为0.1时进行3种不同加载载荷下多试样的疲劳裂纹扩展试验,并测出裂纹扩展长度a和循环寿命N的a-N试验数据。然后采取七点递增多项式法对a-N试验数据拟合计算疲劳裂纹扩展速率。结果表明,加载载荷较小时,ADB610钢循环寿命较长;在疲劳裂纹扩展的初始阶段,加载载荷小的疲劳裂纹扩展速率相对较慢,但随着疲劳裂纹逐渐扩展,加载载荷小的疲劳裂纹扩展速率反而更大一些。

Effect of Load on Fatigue Crack Growth of ADB610 Steel

Under the stress ratio of 0.1,3 different loads were constantly loaded on 3 groups of compact tension specimens of ADB610 low carbon bainite steel to study the growing of the fatigue crack.The a-N test data of crack length a and the cycle life N were obtained from the tests,and the fatigue crack growth rate was calculated by fitting the a-N test data with the seven point fitting method.The resuts showed that when the load was low,the cycle fatingue life was long;in the first phase of growth of fatigue crack,the fatigue crack growth rate of the low-load was relatively low,however,with the fatigue crack developing gradually,the rate of low-load fatigue crack growth would be the higest.