Chemical Treatment

Nickel-Rich Coating for Saline-Alkali Soil Grounding

To improve the corrosion resistance of the grounding grids in saline-alkali soil, the authors fabricated a conductive and anticorrosive coating. After a series of tests, results indicated that an increase of nickel powder in the coating can lead to its electrical conductivity enhancement.

Underdeposit Corrosion in Crude Tower Overheads

Ammonium chloride corrosion is an aggressive form of localized, underdeposit corrosion commonly found in overhead equipment and piping associated with crude units.

Steel Corrosion Under Supercritical CO2 Conditions with Impurities

The corrosion rates were investigated for carbon steel (CS) and Cr-containing steel exposed in water saturated with supercritical carbon dioxide (CO2) for 96 hours with different contents of impurities.

A Closer Look at Microbiologically Influenced Corrosion

Microbiologically influenced corrosion (MIC) refers to corrosion caused by the presence and activities of microorganisms—microalgae, bacteria, and fungi. While microorganisms do not produce unique types of corrosion, they can accelerate corrosion reactions or shift corrosion mechanisms. Microbial action has been identified as a contributor to rapid corrosion of metals and alloys exposed to soils; seawater, distilled water, and freshwater; crude oil, hydrocarbon fuels, and process chemicals; and sewage. Many industries and infrastructure are affected by MIC, including oil production, power generation, transportation, and water and waste water.

Non-Phosphorus Cooling Tower Treatment Provides Advanced Corrosion Protection

In anticipation of the tightening restrictions on phosphorus and many of the metal-bearing compounds currently used in industrial cooling treatment, a “green” corrosion and scale inhibition technology was developed that contains no phosphorus while providing corrosion and scale control performance.

Corrosion Management and the Significance of Regular Reporting

Regular inspection, monitoring, sampling, and chemical treatment activities are needed to mitigate corrosion. Data are not always adequately reported on a regular basis, however, which could gradually render an asset integrity management system less effective.

Chromate Primer Alternative Uses Carbon Nanotubes Modified with Corrosion Inhibitors

Scientists have developed a non-chrome primer system by incorporating carbon nanotubes (CNTs) modified with organic corrosion inhibitors into an epoxy-based resin. The goal of the coating development effort was to identify promising CNT-containing non-chrome primer formulations that perform comparably to traditional chromated ones.

Results Posted for NACE International’s 2016 Annual Corrosion Career Survey

Average annual salaries in 2016 are reported for corrosion professionals in the United States, Canada, United Kingdom, and Europe. A slight gain was seen for the United States and United Kingdom, while a larger increase was recorded in Canada.

Steam Generation

The greatest use of high-temperature water and steam is in electrical power generation. Historically, fossil fuels (i.e., wood, coal, gas, and oil) were used almost exclusively to heat water and make steam until the introduction of nuclear power steam generators in the second part of the 20th century. The two types of power plants are different in many ways; however, they share a reliance on technically advanced water treatment and control for successful operation.

Water Constituents

The concentrations of various substances in water in dissolved, colloidal, or suspended form are typically low but can vary considerably. A hardness value of up to 400 ppm of calcium carbonate (CaCO3), for example, is sometimes tolerated in public supplies, whereas 1 ppm of dissolved iron would be unacceptable. In treated water for high-pressure boilers or where radiation effects are important, as in some nuclear reactors, impurities are measured in very small units such as parts per billion (ppb).

Caustic Treatment of Electric Utility Drum Boilers

Until recently, caustic water treatment was not used in high-pressure electric utility drum boilers in the United States because of concern over caustic gouging. Meanwhile, it was being used successfully in other countries. Many U.S. electric utilities have now converted their drum boilers to caustic treatment. This article describes the basics of caustic treatment and presents two case histories of successful use in the United States.

Failure Analysis: In-Situ Combustion Injector Well Tubing Failure

Severe plugging of in-situ combustion injector wells was found within 15 months of their commissioning in an on-land oil field in western India. Laboratory investigations were made to establish the cause and identify remedial measures. The tubing sections in the vicinity of the combustion front were exposed to an aggravated oxidation environment followed by moisture and oxygen intrusion through corrosion product. This triggered conversion of magnetite into porous, nonprotective hematite. The corrosion inhibitor treatment in the wet phase was found to be ineffective. A large amount of loosely bound corrosion product accumulated at the bottom of the hole during air/water injection. This plugged the well. Suitable well completion for the operating conditions was designed to prevent future failures.

Measurement of a Corrosion Inhibitor Through Online Monitoring

Typical repair of reinforced concrete structures showing corrosion damage involves removal of carbonated or chloride-contaminated concrete and subsequent retrofilling with new concrete. Corrosion inhibitors that can be applied by spraying onto the concrete surface are an alternative. These products are relatively new and only limited long-term monitoring results are available. The combination of an inhibitor with monitoring of the corrosion behavior provides evidence of protection. This article describes long-term monitoring results of protected highway gallery columns in the Swiss Alps.

Copper Pipe Failure by Microbiologically Influenced Corrosion

After a detailed investigation on the failure of copper water service pipes in a water distribution system, microbiologically influenced corrosion (MIC) was found to be the cause. Increased system disinfection appears to have remedied the problem. MIC is often overlooked in corrosion investigations of drinking water systems. This case history is a good example of telltale signs of MIC and the water environments in which this can occur.

Evaluation of the Scale and Inhibition Effect of a Water Stabilizer

The complex effect of a water stabilizer on copper, iron, and zinc ions was tested by spectrophotometry, and its corrosion inhibition on copper alloy tubes was measured using electrochemical methods. The results showed that the water stabilizer not only had a strong antiscaling effect on Ca2+ and Mg2+, but also had certain complex effects on Cu2+ and Zn2+ under conventionally used concentration. The water stabilizer provided insufficient corrosion inhibition on copper tubes at the usual concentration.