摘要
以N,N'-二苄基硫脲(DBTU)为缓蚀剂,将其加入NH4Cl中对SAE1020碳钢进行腐蚀,通过SEM、原位电化学测试探讨了DBTU对NH4Cl腐蚀行为的抑制机理。同时采用第一性原理计算和从头算分子动力学模拟,深入分析了DBTU分子在Fe表面的吸附行为及其对NH4Cl腐蚀过程的抑制效果。实验结果表明,DBTU同时通过提升电荷转移电阻和产物层电阻来有效提高界面处的阻抗,提高了产物膜的致密性与均匀性从而抵抗腐蚀介质渗透。DBTU含量为80 mg/L时SAE1020碳钢的缓蚀效率可达95%左右。DBTU分子的主要活性位点为S原子和邻近的C原子,DBTU在Fe表面的吸附通过4个S—Fe键和1个C—Fe键形成,从而提高了DBTU分子在Fe表面的覆盖度,抑制了NH4Cl水解,降低了腐蚀介质的电荷传递速率。
N,N'-dibenzylthiourea(DBTU)was taken as a corrosion inhibitor and added to the NH4Cl solution for the corrosion of SAE1020 carbon steel.The inhibition mechanism of DBTU against NH4Cl corrosion was discussed through SEM and in-situ electrochemical testing.The first principles calculations and ab initio molecular dynamics simulations were also employed to deeply analyze the adsorption behavior of DBTU molecules on the Fe surface and their inhibitive effects on the NH4Cl corrosion process.The experimental results indicate that DBTU effectively enhances the interfacial impedance by simultaneously increasing the charge transfer resistance and the product layer resistance,thereby improving the compactness and uniformity of the product film to resist the penetration of the corrosive medium.When the DBTU concentration is 80 mg/L,the corrosion inhibition efficiency for SAE1020 carbon steel could reach approximately 95%.The primary active sites of the DBTU molecule are the S atom and the neighboring C atoms.On the Fe surface,DBTU adsorbs through four S—Fe bonds and one C—Fe bond.Therefore,the surface coverage of DBTU molecules is increased and the hydrolysis of NH4Cl is suppressed,which reduces the charge transfer rate of the corrosive medium.
作者
魏晓静
闻小虎
李小龙
葛鹏莉
龙武
WEI Xiaojing;WEN Xiaohu;LI Xiaolong;GE PengLi;LONG Wu(Sinopec Northwest Petroleum Bureau,Key Laboratory of Enhanced Oil Recovery of Fractured-vong Reservoir,Urumqi 830011,China;CNPC Tubular Goods Research Institute,State Key Laboratory of Oil and Gas Equipment,Xi’an 710077,China)
出处
《石油化工》
北大核心
2025年第3期355-363,共9页
Petrochemical Technology
