S2O32-对DP980高强钢在NaCl水溶液中的点蚀行为的影响  

Effect of thiosulfate ion on pitting behavior of DP980 high-strength steel in sodium chloride solution

作　　者：刘景榕 类延华 刘涛 常雪婷 尹衍升 LIE Jingrong;LEI Yanhua;LIE Tao;CHANG Xueting;YIE Yansheng(College of Marine Science and Engineering, Shanghai Maritime University, Shanghai 221306, CUina)

机构地区：[1]上海海事大学海洋科学与工程学院

出　　处：《材料科学与工艺》2019年第4期8-16,共9页Materials Science and Technology

基　　金：国家重点基础研究发展计划科技部重大专项项目(2011BAK10B05,2012BAD29B05);国家重点研发计划项目(2016YFB0300700,2016YFB0300704)

摘　　要：DP980钢是一种冷轧双相高强度结构钢,成本低且具备良好的强度和塑性,在海工领域有巨大的潜在应用价值,但其在苛刻海水环境下的耐腐蚀性能,尤其是耐点蚀等局部腐蚀的能力有待深入研究.本文采用动电位极化法对DP980高强钢在含S2O32-离子的NaCl水溶液中的点蚀行为进行了研究,结果发现:在纯硫代硫酸钠水溶液中,DP980高强钢不发生点蚀;在不同质量分数的NaCl水溶液中,DP980高强钢发生点蚀,且随着Cl-离子浓度的增大,DP980高强钢试样的耐点蚀性能下降明显;向NaCl溶液中加入浓度为0.001、0.01、0.1、1mol/L的Na2S2O3时,DP980高强钢试样的点蚀敏感性降低,点蚀受到明显抑制;随着Na2S2O3浓度的升高,DP980高强钢的腐蚀主要以均匀腐蚀的形式发生;当试样浸泡在不同质量分数(0.1%、1%、10%)NaCl的1mol/LNa2S2O3溶液后,对试样表面腐蚀产物及腐蚀形貌进行扫描电镜观察及能谱分析,显示试样均发生均匀腐蚀,腐蚀产物为铁的硫化物,且未发现明显的点蚀.DP980 is a cold rolled dual phase high-strength structural steel with low cost, good strength, and plasticity. It has great potential application value in marine engineering field. While its anticorrosion resistance in harsh seawater environment especially the ability of local corrosion resistance, such as pitting corrosion behaviors, needs further study. Pitting corrosion behaviors of DP980 high-strength steel in the solution of NaCl and S2O32- were studied by potentiodynamic polarization method. Results show that the pitting corrosion did not appear on the DP980 high-strength steel in the solution of pure Na2S2O3, while in different concentrations of NaCl solution, pitting corrosion occurred and the anticonrosion resistance decreased significantly with the increase of Cl-. When adding low concentration Na2S2O3 into the NaCl solution, e.g., 0.001 mol/L, 0.01 mol/L, and 0.1 mol/L, pitting susceptibility of the DP980 steel decreased and the pitting was obvionsly controlled. When the etchants were added to different mass fractions of NaCl solution in 1 mol/L Na2S2O3, the corrosion products and corrosion morphology were examined using SEM and EDS, and it showed that all the samples had uniform corrosion with no pitting corrosion, and the corrosion products were iron sulfides.

关 键 词：DP980高强钢 点蚀 S2O32- NACL溶液 腐蚀形貌 

分 类 号：TQ149[化学工程]