E690平台用钢耐海洋大气腐蚀模拟

Corrosion resistance of E690 platform steel in simulation marine atmosphere

用周浸加速腐蚀试验、力学性能试验并结合扫描电镜、能谱分析以及透射电镜等方法对比研究了2种满足E690要求的低碳贝氏体钢(3种热处理方式)在模拟海洋大气环境中(0.5 wt%NaCl水溶液)的耐腐蚀性能和拉伸性能的变化。结果表明,在腐蚀初期晶粒越小越容易被腐蚀,成膜更快,有利于锈层的形成;Cu的析出会加速钢的初期腐蚀,在腐蚀后期形成致密锈层后这种影响变小。3种实验钢的腐蚀产物相组成差别不大,但锈层致密程度存在差异,并且锈层越致密,对应的钢的腐蚀速率越低。在试验环境中腐蚀对2种试验钢和3种处理方式的力学性能影响较小,说明没有产生严重的局部腐蚀。

The corrosion resistances and tensile properties of two kinds of low carbon bainite steel（E690）（3 kinds of heat treatment processes） were comparative studied in simulation marine atmosphere（0.5wt%NaCl solution）through the wet-dry accelerated corrosion test,mechanical property test,scanning electron microscopy（SEM） and transmission electron microscope（TEM）.The experimental results show that in the early stage of corrosion,the less grain is easier to be corroded,and faster to form film and advantageous for the formation of the rusty layer.The early corrosion of steel will be accelerated by Cu precipitation,while this influence will be less after forming dense rusty layer at the later stage of corrosion.The constitutions of the corrosion products of two kinds of tested steel differ little,but the rusty layer density varies.Moreover,the denser the rusty layers,the lower the corrosion rate of the corresponding steel.The corrosion in the experimental environment has little effect on the tensile mechanical properties,showing no serious selective corrosion produced.