应变速率和电位对应力腐蚀裂纹扩展的影响

以滑移-溶解-再钝化模型为基础,推导出应力腐蚀裂纹扩展速率与裂尖应变速率和电位之间的理论公式.计算表明,在裂纹扩展速率与裂尖应变速率的关系曲线中有两个特征区域.裂纹扩展速率在区域I随裂尖应变速率增加而增大,而在区域II不随裂尖应变速率的改变而变化.用慢应变速率拉伸技术（SSRT）测量了304L不锈钢的裂纹增长速率.当电位控制在区域II的阳极区时,理论计算的裂纹扩展速率与实验得到的结果比较吻合.

Effect of Strain Rate and Potential on the Propagation of Stress Corrosion Crack

On the basis of the model of slip bare metal dissolution repassivation and crack tip strain analysis,a theoretical equation of stress corrosion crack propagation rate as a function of crack tip strain rate and potential for 304L stainless steel in acidic chloride solution was deduced.The theoretical prediction showed that there are two regions in the curve of crack propagation rate with the crack tip strain rate.In region I,the crack growth rate increased with increasing crack tip strain rate.In region II,the crack propagation rate was independence of the crack tip strain rate.The crack propagation rate of 304L stainless steel in acidic chloride solution has been measured by slow strain rate testing (SSRT) technique.The crack propagation rate calculated theoretically was consistent with the experimental results in region II when potential was controlled in anodic region.