L245NS钢在不同含硫条件下腐蚀特性与缓蚀行为研究

Corrosion Characteristics and Inhibition Behavior of L245NS Steel under Different Sulfur Conditions

本文主要通过动电位极化扫描和电化学交流阻抗方法针对L245NS管线钢在含硫环境下且含不同浓度季胺化咪唑啉缓蚀剂下的电化学腐蚀特性和缓蚀行为进行了研究。研究结果表明:(1)在“1%NaCl+饱和CO_(2)基础介质”和“1%NaCl+0.5%Na;S·9H_(2)O+饱和CO_(2)基础介质”中分别加入不同硫含量Na;S·9H_(2)O物质和缓蚀剂后,L245NS钢的腐蚀电流密度均呈现减小规律,Na;S·9H_(2)O浓度由0.5%增至1%腐蚀电流密度减小显著,缓蚀剂浓度为200ppm时缓蚀效率达64.6%;(2)在0.1%和0.5%Na;S·9H_(2)O含硫环境及不同缓蚀剂浓度环境中,阻抗谱呈现中高频区的容抗弧和低频区的Warburg阻抗扩散的特征,但达1%Na;S·9H_(2)O时低频区的Warburg阻抗特征消逝;(3)容抗弧直径随含硫量和缓蚀剂浓度的增加而增大,阻抗性增大。

In this paper, the electrochemical corrosion characteristics and corrosion inhibition behavior of L245NS pipeline steel in sulfur-containing environment and with different concentrations of quaternized imidazoline corrosion inhibitors were studied by potentiodynamic polarization scanning and electrochemical impedance spectroscopy. The results showed that the corrosion current density icorr of L245NS steel decreased with the addition of Na;S·9H_(2)O and corrosion inhibitor with different sulfur contents in‘1% NaCl+saturated CO_(2)basic medium’and‘1% NaCl+0.5% Na;S·9H_(2)O+saturated CO_(2)basic medium’, respectively. The corrosion current density decreased significantly with the increase of Na;S·9H_(2)O concentration from 0.5% to 1%, and the corrosion inhibition efficiency reached 64.6% when the corrosion inhibitor concentration was 200 ppm. In 0.1% and 0.5% Na;S · 9H_(2)O sulfur-containing environment and different corrosion inhibitor concentration environment, the impedance spectrum shows the characteristics of capacitance arc in the middle and high frequency region and Warburg impedance diffusion in the low frequency region, but when it reaches 1 % Na;S· 9H_(2)O, the Warburg impedance characteristics in the low frequency region disappear;the diameter of capacitance arc increases with the increase of sulfur content and inhibitor concentration, and the impedance increases.