板厚对14MnNbq钢焊接件疲劳裂纹扩展速率的影响

为研究厚板的原始焊接板厚及取样位置对疲劳裂纹扩展速率的影响规律,完成了14MnNbq钢5种原始焊接板厚（40 mm、50 mm、60 mm、80 mm和100 mm）,共计30个疲劳试件的裂纹扩展试验。运用数理统计方法回归处理试验数据,得到了在给定置信水平下的5组da/dN-ΔK曲线以及Paris公式的拟合值参量,同时还得到了100 mm厚板不同取样部位的da/dN-ΔK曲线。结果表明：随着原始焊接板厚的增加,疲劳裂纹扩展速率也在加大;受取样位置的影响,表面试件比中部试件的疲劳裂纹扩展速率快。

Thickness Influence on the Fatigue Crack Growth Rate of 14MnNbq Steel Welding Assembly

To study the effect of thick plate＇s original welding thickness and specimen location on the fatigue crack growth rate,the fatigue crack growth tests for 30 fatigue testing specimens made from 14MnNbq steel with five variables of original welding thickness（i.e.40mm,50mm,60mm,80mm and 100mm） were conducted.Mathematical Statistics was used to deal with the test data,by this means the da/dN-ΔK curves and the parameters for Paris formula were obtained under a given confidence.The results show that,the fatigue crack growth rate increases along with addition of original welding thickness.Besides,considering the effect of the location of specimen,the fatigue crack growth rates of external specimens are faster than those of internal.