论文部分内容阅读
通过波动拉伸载荷试验(F-SSRT),研究了不同应变速率对X7 0管线钢在阴极电位下近中性介质应力腐蚀开裂(SCC)行为的影响。结果表明:X7 0管线钢在特定的近中性介质中,在波动拉伸载荷和阴极电位(-850 mVSCE)条件下,存在SCC敏感性。在波动拉伸载荷试验条件下,SCC裂纹的扩展机理与匀速慢拉伸试验时不同,SCC裂纹可以从材料表面产生的微孔处萌生并沿主应力面扩展,当应变速率在一定范围时,SCC裂纹转变为沿45°最大剪应力面扩展。还分析了波动拉伸载荷试验中氢在X70管线钢SCC发展过程中的作用和机理。
The effect of different strain rates on the stress corrosion cracking (SCC) behavior of near-neutral medium of X7 0 pipeline steel at cathodic potential was studied by the wave tensile load test (F-SSRT). The results show that there is SCC susceptibility for X7 0 pipeline steel in a particular near neutral medium under fluctuating tensile load and cathodic potential (-850 mVSCE). Under the condition of fluctuating tensile load, the propagation mechanism of SCC crack is different from that under uniform slow-speed tensile test. The crack of SCC can initiate from the micropores generated on the material surface and spread along the principal stress plane. When the strain rate is within a certain range, SCC crack transitions to 45 ° maximum shear stress plane expansion. The role and mechanism of hydrogen in the development of SCC of X70 pipeline steel in fluctuating tensile load tests were also analyzed.