水体氮磷无机盐对X70碳钢腐蚀影响研究

发布时间：2018-01-15 16:18

本文关键词：水体氮磷无机盐对X70碳钢腐蚀影响研究　出处：《浙江海洋大学》2017年硕士论文　论文类型：学位论文

【摘要】：目前我国水体富营养化主要原因之一是氮磷超标,同时油气储运相关的设备常常处于富营养化的水体环境中。故本文从腐蚀的角度探讨了富营养化环境对管线钢可能产生的影响,选择了典型的氮磷无机盐和常用管线钢X70碳钢为研究载体,采用了电化学阻抗谱,极化曲线,失重法,腐蚀形貌和产物分析,从多角度研究了氮磷无机盐对X70碳钢的腐蚀影响。研究结果如下:(1)失重法表明随着氮磷浓度增加,溶液对X70碳钢的缓蚀作用越明显;(2)形貌观察初步发现随着溶液浓度的增加氮磷无机盐溶液中的碳钢腐蚀程度有显著不同,且有不同形貌的腐蚀产物层;(3)交流阻抗谱和极化曲线试验表明在水体环境中氮磷无机盐对碳钢均有不同程度的缓蚀作用,缓蚀作用大小比较为:氮盐:NaNO_2NaNO_3(NH_4)_2SO_4,磷盐:Na_2HPO_4NaH_2PO_4Na_3PO_4;(4)产物分析表明(NH_4)_2SO_4通过促进Si和Ca的氧化物形成使得腐蚀产物的更加致密;NaNO?和NaNO_3不但能够促进Si和Ca的氧化物形成,而且能够加速铁的氧化物形成在碳钢表面形成致密产物膜,但NaNO?作用更强;磷盐通过在碳钢表面形成相应的结晶吸附于碳钢表面抑制腐蚀的发生,同时NaH_2PO_4还可以促进Ca的氧化物形成增加碳钢表面缓蚀膜的厚度抑制腐蚀。本文研究结果不但可以为油气储运设备安全提供参考,而且可以为碳钢防腐提供理论基础。
[Abstract]:At present, China's water eutrophication is one of the main reasons for nitrogen and phosphorus exceed the standard, at the same time, the oil and gas storage and transportation related equipment are often in water eutrophication. So this paper from the angle of the corrosion effects of eutrophication may have on pipeline steel, X70 steel selected inorganic nitrogen and phosphorus salts of typical and commonly used steel as the research carrier, the electrochemical impedance spectroscopy, using the weight loss method, polarization curve, corrosion morphology and product analysis, to study the effects of nitrogen and phosphorus inorganic salt on the corrosion of X70 steel. The results are as follows: (1) showed that with the increase of concentration of nitrogen and phosphorus loss method, X70 solution on the corrosion inhibition the role of the more obvious; (2) the morphology was found to increase with the concentration of the solution the corrosion degree of inorganic nitrogen and phosphorus in salt solution is significantly different, and the corrosion product layer with different morphologies; (3) show that the AC impedance spectra and polarization curve test The inhibition effect of inorganic nitrogen and phosphorus salts on carbon steel in varying degrees in water environment, corrosion inhibition of size: nitrogen: NaNO_2NaNO_3 (NH_4) _2SO_4, P: Na_2HPO_4NaH_2PO_4Na_3PO_4; (4) the product analysis showed that _2SO_4 (NH_4) Si and Ca oxidation by promoting the formation of the corrosion products more compact.; NaNO? And NaNO_3 not only can promote Si and Ca oxide formation, but also can accelerate the formation of dense iron oxide film on the surface of carbon steel products, but NaNO? Stronger; phosphate salt crystallization by corresponding adsorption on the surface of carbon steel corrosion inhibiting formation on the surface of carbon steel, and NaH_2PO_4 can promote Ca oxide increased formation of steel surface corrosion film thickness inhibiting corrosion. The results of this study can not only provide reference for the safety of oil and gas storage and transportation equipment, and can provide theoretical basis for carbon steel corrosion.

【学位授予单位】：浙江海洋大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE980.1

【相似文献】