油田水处理区腐蚀规律及酸化用酰胺类缓蚀剂研究

发布时间：2018-03-04 22:07

  本文选题：碳钢　切入点：缓蚀剂　出处：《江西理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：碳钢在不同介质中的腐蚀机理各不相同,本文从多种介质入手,研究碳钢的腐蚀规律和机理。实验分为油田水处理区现场腐蚀实验和实验室静态挂片实验。油田现场实验分为现场取样模拟实验和水处理区现场投放挂片在线实验。从水处理区腐蚀实验中统计碳钢在油气处理厂水处理区的腐蚀趋势和规律。通过实验室静态挂片实验电化学实验研究碳钢在HF介质中腐蚀机理,并设计合成相应的酸化用缓蚀剂。缓蚀剂通过硫脲与L-半胱氨酸的酰化反应制备得到,目标主产物为(2-氨基-2-巯基-乙酰基)-硫脲(ASAT)。缓蚀剂分别在1%,2%和5%HF中进行研究;实验温度设计为常温、40℃、45℃。通过静态挂片法、Langmuir等温吸附线、阻抗谱(EIS)、极化曲线等手段研究碳钢在HF介质中的腐蚀机理以及缓蚀剂的效果和缓蚀机理。采用静态挂片法和Langmuir等温吸附法来研究腐蚀介质中缓蚀剂在碳钢表面的吸附情况,经过计算得出缓蚀剂在碳钢表面的吸附模型为单分子层化学吸附。缓蚀剂在碳钢表面的吸附反应可分为两种情况:(1)高温下有发生吸附反应的趋势但不自发吸附,(2)低温下有发生吸附反应的趋势,可以自发吸附。通过极化曲线与阻抗谱可以看出缓蚀剂在此系统中起到了一定的缓蚀效果,探究出碳钢在HF中的腐蚀机理以及腐蚀速率同介质温度、HF浓度之间的关系,同时分析得出以(2-氨基-2-巯基-乙酰基)-硫脲为主要成分的缓蚀剂的缓蚀机理。极化曲线表明该缓蚀剂为阳极型缓蚀剂。对比各温度下的实验数据发现,温度和HF浓度越高,腐蚀电流密度越大,腐蚀速率越快,温度和氢氟酸浓度会影响碳钢的腐蚀速率。在光学显微镜下观察发现,碳钢在各浓度HF介质中腐蚀一段时间后会出现均匀腐蚀和点蚀现象,在扫面电镜下发现针状腐蚀产物疏松的堆积在碳钢表面。
[Abstract]:The corrosion mechanism of carbon steel in different media is different. The corrosion law and mechanism of carbon steel were studied. The experiments were divided into field corrosion experiment in oilfield water treatment area and static hanging sheet experiment in laboratory. The corrosion tendency and regularity of carbon steel in water treatment area of oil and gas treatment plant were analyzed from the corrosion experiment of water treatment area. The corrosion mechanism of carbon steel in HF medium was studied by electrochemical experiment of static hanging sheet in laboratory. The corrosion inhibitor was prepared by acylation of thiourea and L-cysteine. The main product was 2-amino-2-mercapto-acetyl-thiourea. The inhibitor was studied in 1% and 5HF, respectively. The experimental temperature was designed as normal temperature 40 鈩，

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