Metal Corrosion and Corrosion Protection

Аннотация

The article explains how to protect the equipment and tools from corrosion and protection of them during operation and maintenance. It provides information on the methods of protection against external and internal corrosion. KEY WORDS: corrosion, corrosion environment, metal, direct corrosion, indirect corrosion, corrosion resistance, chemical corrosion, electrochemical corrosion, anode, cathode, passivation I.INTRODUCTION As a result of the development of a wide range of industries following the independence of the Republic, modern technological methods, equipment and tools are being used. Corrosion protection is one of the most important tasks in maintaining equipment and reliability during operation of equipment and tools. Specifically, the general pollution of the atmosphere with various corrosive substances, as well as the peculiarities of the products used in the extraction, storage and transportation of oil and gas products, require increased corrosion resistance of the equipment used in this field. II. METHODOLOGY Corrosion is the process of decomposition of metals as a result of chemical or electrochemical interaction of metals with corrosive environments. Corrosive environments are aggressive atmospheric metals, acid solutions, alkalis, salts and other environments that cause corrosion processes of metals. Many metals are oxidized and degraded due to thermodynamic instability under aggressive media. As a result of corrosion processes of metals, their mass decreases, and the necessary technological properties change: mechanical strength, plasticity, and size. Corrosion is one of the major decay factors that can lead to the failure and uselessness of parts and mechanisms. Corrosion can be attributed to direct and indirect losses. Indirect corrosion removal costs include protection costs and complete failure of metal as a result of loss of working capacity. According to experts, the total metal defect is currently 10-15% per annum. Indirect corrosion losses include the decline in the quality and volume of manufactured products as a result of a decrease in the productivity of the equipment and an increase in metal consumption. Corrosion in the oil and gas industry has led to the decline in productivity and failure of many equipment. This includes pipes, taps and reservoirs. The ability of metals to withstand corrosion is called corrosion resistance. Metal and their alloys have different corrosion resistance in different temperatures and in different environments. Anti-corrosion protection sets the task of exploring methods of protection and protection of metals and alloys, depending on the internal and external environment. The methods of corrosion protection are subdivided into design, technological and operational activities, and their methods are developed based on experimental corrosion studies. Copyright to IJARSET www.ijarset.com 12911 ISSN: 2350-0328 International Journal of Advanced Research in Science, Engineering and Technology Vol. 7, Issue 2 , February 2020 Corrosion processes are classified into chemical and electrochemical corrosion by the mechanism of reactions occurring on the metal surface. Chemical corrosion is caused by processes that interact with the metal in an aggressive environment. Chemical corrosion is caused by chemical heterogeneous reactions of liquid or gaseous environments with metal surfaces, and there is no induction of electrical current. Corrosion is observed on the metal surface under the influence of dry gases and vapors, liquid electrolytes (oil and its products, alcohols, mineral oils, organic compounds). Electrochemical corrosion Heterogeneous electrochemical reactions include processes occurring in aqueous solutions, in wet gases, in salt and alkaline solutions, and by the interaction of metal with the environment. Electrochemical corrosion can be classified according to the conditions, environmental properties, and other species. Depending on the types of aggressive environments, corrosion processes are divided into atmospheric, gas, fluid, soil, biodegradable currents, and biological corrosion. Depending on the occurrence, there are corrosion processes in contact (different metals compounds), intermediate (space between two metals), and voltage. Under the influence of external factors on the corrosion processes, the characteristics, kinetics and mechanisms of corrosion degradation change. III. RESULTS Depending on the characteristics of corrosion damage and the conditions of its formation, they are divided into general (complete), local and selective corrosion. Due to the corrosion damage of metal objects, high losses require the development of anti-corrosion protection methods. The most common methods of corrosion protection are to obtain corrosion-resistant layers on the surface of the products. These methods include plastic, composition polymer, varnish coating, enamel coating. The methods of coating the metal surface with other metals are widely used. me