恒幅载荷ADB610钢疲劳裂纹扩展规律研究

Fatigue Crack Growth of ADB610 Steel under Constant-load

本文对国产新一代600MPa级低焊接裂纹敏感性低碳贝氏体钢ADB610钢进行疲劳裂纹扩展试验,研究其疲劳裂纹扩展规律。在厚度为20 mm的ADB610钢板上截取7个CT(紧凑拉伸)试样,在应力比为0.1时,采用恒幅载荷实验法进行疲劳裂纹扩展试验,得到每个试样的裂纹扩展长度a与裂纹扩展寿命N之间的a-N试验结果。对每个试样的a-N试验结果,采用一次七点递增多项式拟合方法,运用MATLAB软件编程,分别计算出每个试样的裂纹扩展速率以及基于Paris公式的疲劳裂纹扩展速率表达式。并将这7个试样Paris公式中的参数取平均值,得到了均值裂纹扩展速率表达式,从而得到ADB610钢的疲劳裂纹扩展规律。

ADB610 steel is a newly developed low-carbon bainite steel, which has low welding crack sensitivity. The fatigue crack growth property of ADB610 steel were studied based on fatigue crack growth test. Seven CT （Compact Tensile） samples were obtained from ADB610 steel plate, and fa- tigue crack growth test was carried out using constant-load testing method and the stress ratio was 0. 1. The a-N test results of 7 samples were obtained. The fatigue crack growth rate equation based on Paris of each sample was calculated respectively using once seven point fitting method and MATLAB soft- ware. The average values of parameters in Paris equations of 7 samples were calculated, and it was ob- tained for the average fatigue crack growth rate equation. ADB610 steel fatigue crack growth property using constant-load testing method was also got.