(NH_4)_2SO_4浆液中Q235钢缓蚀剂性能

Performance of corrosion inhibitor for Q235 steel in ammonium sulfate solution

通过电化学方法和质量差法对Q235钢在Cl-质量分数为1%、(NH4)2SO4质量分数为5%、p H为5.0、温度为65℃以及流速为0.424 m/s的(NH4)2SO4浆液中进行缓蚀剂的筛选和研究,并用交流阻抗法研究了两者复配的缓蚀机制。结果表明:单组分三乙烯四胺和Na2Mo O4的缓蚀率均在90%左右;Na2Mo O4是以抑制阳极过程为主的缓蚀剂,三乙烯四胺是混合型缓蚀剂;Na2Mo O4和三乙烯四胺两者复配后腐蚀电流密度大大减小,在缓释剂总量为1%,两者质量比为1∶1时,缓蚀率最大为95.76%;Na2Mo O4吸附形成一层不致密的保护膜,而三乙烯四胺的4个N原子可以作为4个活性吸附中心,使其牢牢地吸附在缝隙之间,从而两者复配之后形成一层完整的保护膜。

Under the conditions of Cl^- mass content 1%,the mass content of ammonium sulfate 5%,p H5. 0,the temperature 65 ℃ and the flow rate 0. 424 m / s,the corrosion inhibitor for Q235 steel in ammonium sulfate solution was investigated by the polarization curves and the weight-loss method. And the AC impedance method was used to study the inhibitor mechanism of combined inhibitors. Results showed that the corrosion inhibitor efficiency of single-component triethylene tetramine and sodium molybdate were both about 90%. Sodium molybdate mainly inhibited the anodic process,and the triethylene tetramine belonged to the mixed corrosion inhibitor. When corrosion inhibitors were compounded,the corrosion current density decreased greatly. When triethylene tetramine and sodium molybdate ratio was 1∶ 1,and the total amount was 1%,the corrosion inhibitor efficiency reached to the maximum at 95. 76%. And sodium molybdate could be adsorbed and formed a not very compact layer.Four N atoms of triethylene tetramine could be used as the four centers of the active adsorption,making the membrane firmly adsorbed between cracks. Thus the combined inhibitors formed a complete protective membrane.