不同外加电位下X80管线钢在近中性pH溶液环境中的裂纹扩展行为研究

发布时间：2018-04-24 18:52

本文选题：X管线钢 + 外加电位　；参考：《表面技术》2015年03期

【摘要】：目的研究不同外加电位下,X80管线钢在近中性p H溶液环境中的裂纹扩展行为。方法对X80管线钢紧凑拉伸试样进行近中性p H溶液环境中的循环加载试验,利用拍摄装置记录不同循环次数下的裂纹长度,并利用扫描电镜(SEM)观察裂纹扩展面上的微观形貌。研究不同外加电位下,X80钢在近中性p H溶液环境中的裂纹扩展速率,分析其裂纹扩展规律。结果在开路条件下,循环加载755次时,裂纹扩展4.6 mm后失稳断裂;在外加电位为-775 m V(vs.SCE)的条件下,循环加载671次时,裂纹扩展3.677 mm后失稳断裂;在外加电位为-1125 m V(vs.SCE)的条件下,循环加载625次时,裂纹扩展3.882 mm后失稳断裂。结论在开路电位和弱阴极电位下,裂纹扩展受到阳极溶解机制和氢脆机制的混合控制,以阳极溶解机制为主,裂纹扩展速率均较低;随着外加电位降低,裂纹扩展机制逐渐过渡为主要受氢致开裂作用控制,裂纹扩展速率显著增加。
[Abstract]:Aim to study the crack propagation behavior of X80 pipeline steel under different applied potentials in near neutral pH solution. Methods the compact tensile specimens of X80 pipeline steel were subjected to cyclic loading in near-neutral pH solution. The crack length was recorded under different cycles and the micromorphology of the crack growth surface was observed by SEM (SEM). The crack propagation rate of X80 steel under different applied potentials in near-neutral pH solution was studied and its crack propagation law was analyzed. Results under open circuit condition, the crack propagates 4.6 mm after cyclic loading for 755 times, and under the applied potential of -775 m V / v 路s. SCE, the crack propagates 3.677 mm after cyclic loading for 671 times, and the applied potential is -1125 m V / v / v 路SCE). When cyclic loading is 625 times, the crack propagates 3.882 mm and the fracture is unstable. Conclusion at open circuit potential and weak cathode potential, the crack propagation is controlled by the mixed mechanism of anodic dissolution and hydrogen embrittlement, the anodic dissolution mechanism is dominant, the crack growth rate is lower, and the crack growth rate decreases with the applied potential. The mechanism of crack growth is mainly controlled by hydrogen induced cracking, and the rate of crack growth increases significantly.
【作者单位】：北京科技大学腐蚀与防护中心;
【基金】：国家高技术研究发展计划(863计划,2012AA040105) 国家自然科学基金(51471034) 北京市青年英才计划资助~~
【分类号】：TG142.1

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