应力比对高强钢丝腐蚀疲劳寿命的影响研究

Effect of stress ratio on corrosion fatigue life of high-strength steel wire

建立了高强钢丝腐蚀疲劳寿命模型,用于预测不同应力比和应力范围下的腐蚀疲劳寿命,研究应力比对腐蚀疲劳寿命的影响。利用应力比与应力范围之间的关系,处理了不同应力比和应力范围下高强钢丝腐蚀疲劳耦合试验数据。基于处理后的试验数据,对寿命模型进行参数估计,建立了高强钢丝腐蚀疲劳寿命模型,研究了不同应力比下腐蚀疲劳寿命的演化规律。结果表明:高强钢丝腐蚀疲劳寿命模型的预测值与试验数据吻合较好。该模型对高应力范围的腐蚀疲劳寿命预测值小于试验数据,对低应力范围的腐蚀疲劳寿命预测值大于试验数据。随着应力比的增大,高强钢丝的S-N曲线逐渐左移,而且斜率的绝对值逐渐变小。高强钢丝的腐蚀疲劳寿命随应力比的增大而减小。当应力比较大时,应力范围对腐蚀疲劳寿命的影响减小。应力比对低应力范围下的腐蚀疲劳寿命影响更显著。

In this paper,the corrosion fatigue life model of high-strength steel wire is established to predict the corrosion fatigue life under different stress ratios and stress ranges,and the effect of stress ratio on corrosion fatigue life is investigated.The corrosion fatigue coupling experimental data of highstrength steel wire under different stress ratios and stress ranges are processed by using the relationship between stress ratio and stress range.Based on the processed experimental data,the parameters of the life model are estimated,and the corrosion fatigue life model of high-strength steel wire is established.The evolution law of corrosion fatigue life under different stress ratios is examined.The results show that the predicted value of the corrosion fatigue life model is in good agreement with the experimental data.The predicted value of corrosion fatigue life in high stress range is less than the experimental data,while that in low stress range is greater than the experimental data.With an increase of the stress ratio,the S-N curve of the high-strength steel wire gradually shifts to the left,and the absolute value of the slope decreases.Corrosion fatigue life of high-strength steel wire decreases with an increase of the stress ratio.The influence of stress range on corrosion fatigue life is reduced under large stress ratio.The stress ratio has a more significant effect on the corrosion fatigue life in the low stress range.