Why is it necessary to carry out corrosion monitoring and what is its significance?
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Why is it necessary to carry out corrosion monitoring and what is its significance? 1. To provide a basis for scientific management and decision-making: In the process of petroleum refining, corrosion inhibitors are used in large quantities to reduce internal corrosion of process equipment. However, whether the type and ratio of the added corrosion inhibitor are suitable for this system can only be determined through certain measurements. By using corrosion monitoring, it is possible to continuously assess the effectiveness of the corrosion inhibitor, and to adjust the type or ratio of the inhibitor in a timely manner based on the monitoring results ； 2. Preventing accidents: Harmful leaks or changes in process parameters can sometimes lead to severe corrosion. By using corrosion monitoring, it is possible to keep an eye on the corrosion status of the medium at any time. If a sudden change in the corrosion rate is detected, the system is inspected immediately to identify the problem promptly and prevent serious accidents from occurring ； 3. Predicting equipment lifespan: By monitoring corrosion, it is possible to accurately determine the rate of corrosion when the equipment is operating properly, thereby allowing for the prediction of its service life – ensuring both safety and cost-effectiveness ； 4. Economy, safety, and environmental improvement. In addition to bringing substantial economic benefits by improving the operating condition of equipment, enhancing its reliability, prolonging its service life, and reducing downtime for maintenance, corrosion monitoring technology also enables the installation to operate under conditions as close as possible to those optimal for design. It can also contribute to ensuring the safety of the equipment, protecting the safety of operators, and reducing environmental pollution ； 5. Provide equipment corrosion analysis data. Corrosion monitoring is also useful for analyzing the causes of corrosion, understanding the relationship between the corrosion process and process parameters, or evaluating the actual effectiveness of various anti-corrosion methods.
The purpose of conducting corrosion monitoring is to provide a basis for scientific management, prevent accidents, predict the lifespan of equipment, ensure economic and safe operation, improve the environment, and supply data for equipment corrosion analysis. .
Corrosion monitoring is necessary, but it is a major project that requires a long time to complete; currently, not many people are engaged in it
Corrosion is relatively severe and mainly occurs in the following systems: the low-temperature areas of the ‘three tops’ in the atmospheric and vacuum distillation units, as well as the condensation and cooling systems for light oils such as those in the vaporization line; the main corrosive environment in these areas is H2S-HCL-H2O； Corrosion morphology: uniform thinning for carbon steel, pitting for Cr13 steel, and chloride stress corrosion cracking for 1Cr18Ni9Ti steel. The condensation and cooling systems of secondary processing units such as catalytic cracking are primarily exposed to a corrosive environment consisting of H2S, HCN, NH3, and H2O ； Corrosion morphology: for carbon steel, it is uniform thinning, hydrogen blistering, and sulfide stress corrosion cracking; for austenitic stainless steels, it is sulfide stress corrosion cracking. High-temperature areas such as the oil transfer lines in heating furnaces and towers; the corrosive environment is high-temperature H2S-RSH (thiols), with uniform corrosion being the form of corrosion ； In the high-temperature areas of refining systems such as hydrocracking and hydrorefining, the corrosive environment is high-temperature H2-H2S ； Corrosion patterns: For carbon steel, it involves uniform corrosion, hydrogen embrittlement, and hydrogen corrosion; for 1Cr18Ni9Ti steel pipe bundles, various types of stress corrosion cracking also occur. Flue gas dew point corrosion in the low-temperature areas of equipment such as the convection chamber of heating furnaces, waste heat recovery systems, and waste heat boilers; the corrosive environment consists of CO2-O2-SO2-SO3-H2O ； Corrosion pattern: Stress corrosion cracking in carbon steel.
This monitoring is essential; for containers and pipes to function properly, strength and stiffness are necessary, so it is important to monitor their corrosion status
In fact, not only containers and pipes, but also important steel structures should undergo such inspections to ensure proper use