盲孔法测试Q690高强钢管镀锌前后残余应力

EXPERIMENTAL STUDY ON THE RESIDUAL STRESS OF Q690 HIGH-STRENGTH STEEL PIPE BEFORE AND AFTER GALVANIZATION USING BLIND-HOLE METHOD

残余应力对轴心受压构件的稳定性等有重要影响,为考察Q690焊接高强钢管镀锌前后的截面纵向残余应力分布,该文采用盲孔法对截面规格分别为φ250×8、φ300×8和φ350×8共计24个试件的残余应力进行测试。通过试验得出了每种截面规格圆钢管的纵向残余应力的数值大小和分布模式,并将相同截面规格的钢管在镀锌前后的残余应力分布进行了比较,试验结果表明,钢管镀锌后残余应力有了明显的降低。通过对Q690未镀锌钢管的试验结果总结发现,Q690高强钢管的截面最大纵向残余应力与其钢材屈服强度的比值明显小于普通钢材:普通钢材为0.35,而该次试验测得的最大值为0.15。

Residual stress has an important impact on the stability and other performances of axial compression members. In order to study the influence of galvanization on residual stress distribution of Q690 high-strength steel pipe, a total of 24 specimens, with three cross-sectional specifications as φ250×8, φ300×8 and φ350×8, are tested using blind-hole method. The longitudinal residual stress magnitude and distribution pattern of each cross-sectional specification are obtained. The residual stress distribution of the same cross-section steel pipe before and after galvanization was compared. The results show that the residual stress of the steel pipe after galvanization is significantly reduced. The ratio of the peak residual stress to the yield strength of Q690 high-strength steel pipe is 0.15, which is significantly less than that of ordinary strength steel pipe with a value of 0.35.