Northern Technologies International (United States)

Abstract The NACE TM0208-2018 standard jar test is a widely used tool for measuring the efficacy of volatile corrosion inhibitor (VCI) packaging materials to provide off-contact corrosion protection of steel surfaces. However, while ever improving, the standard still lacks sufficient technical specification for some of the materials used during the test procedure, which likely contributes to inconsistent results observed both within and between laboratories. For example, the use of mineral spirits to clean the steel specimen surfaces is unique to the TM0208 standard, but no comment or requirement is made about which of the various types and grades of mineral spirits should be used. In this paper, we investigate how cleaning the steel specimen surfaces with different grades of mineral spirits impacts their corrosion protection by VCI chemistries. In addition, we further explore how changes in the temperature and duration of the mineral spirits bath, together with covering the bath during cleaning, impact the sensitivity of the steel surfaces to corrosion. Ultimately, we correlate corrosion sensitivity with surface energy as measured by the contact angle of water droplets deposited on the surface of the steel specimens after completion of the TM0208 test.

Abstract Aboveground storage tanks are mission critical assets in the chemical and petrochemical industries. Corrosion of tank bottom plates poses a significant challenge to maintaining the integrity of those assets. Coatings have been shown to be effective in mitigating corrosion on the product side of the bottom plates, but aren’t viable for providing corrosion protection to the soil-side of the bottom plates. Volatile corrosion inhibitors have gained industry acceptance as an effective means in mitigating corrosion of the soil-side of the bottom plates and have been utilized across a wide variety of tank foundation designs, including a concrete ring wall, double bottom and hard pad, such as concrete or asphalt. Volatile corrosion inhibitors can also mitigate corrosion for soil-side bottoms in areas where traditional cathodic protection systems are not effective, such as double bottoms, hard pads or when the cathodic protection system has failed. Electrical resistance probes are typically utilized to monitor the effectiveness of the volatile corrosion inhibitors in mitigating corrosion of the soil side bottom plates. Data will be presented from multiple installations demonstrating the ability of volatile corrosion inhibitors to mitigate corrosion for soil-side bottoms.

<div class="section abstract"><div class="htmlview paragraph">The power demands in terms of kilowatt-hour electrical use were compared for autoclave curing commercial thermosetting carbon fiber pre-pregs with an innovative alternative of high energy X-ray curing. An automotive component, now made with carbon fiber composites, was selected as an illustrative example, an Aston-Martin hood. Temperature resistant polyester molds for these hoods were used and manufacturer recommended autoclave curing conditions were followed. X-rays, which can penetrate about 15 cm (6 inches) in unit density materials (or less into higher density materials as molds), were used to cure pre-pregs made with a specialty matrix material using the same molds, but doing so without adding any heat for curing. High energy X-ray equipment, generated from a 7 MeV, 700 kW electron beam, is in commercial use for medical device sterilization. This same equipment can also be used for composite curing. Automotive components can be exposed on a continuous basis by passing them in front of the X-ray source. Such electrical sources must be enclosed within thick shielding structures to prevent X-radiation from entering the workplace. Feasibility studies, relying upon vacuum assisted resin transfer molding (VARTM), had shown that select combinations of functional monomers and oligomers can be formulated for the X-ray curing of carbon fiber composites within molds. The viscosity of these epoxy based materials was increased for their use as the matrices in pre-pregs. Dynamic mechanical analyses of cured components were used to assess some performance parameters. The New York State Vehicle Composites Program and the prior feasibility studies on X-ray curing were supported by the New York State Energy Research and Development Authority.</div></div>

Abstract Corrosion of soil side bottoms is unpredictable and can be up to 5 mm/year. The soil side bottom cannot be protected while the tank is in service. The well-known cathodic protection system is not efficient enough. This paper presents case studies of soil side bottom corrosion protection using new systems with volatile and soluble corrosion inhibitors installed on new and existing soil side and double bottom aboveground storage tanks. This paper describes field trial and application experience of principally new corrosion protection systems for different designs of storage tank foundations. The new system demonstrates corrosion protection efficiencies as high as 70-90% and also decreases the incidence of pitting corrosion in most aggressive environment conditions. Application experience has shown that inhibitor use can increase the tank service life approximately 3-5 times and reduce maintenance and replacement costs.

Abstract Existing corrosion protection methods for mothballed equipment during long term (6 months – 10 years+) storage and shipment in unpredictable environmental and application conditions are not always effective. In addition to their limited protection offered, these approaches tend to be cumbersome, complicated, labor intensive and therefore very expensive. This paper describes a system that allows replacement of the technology by using inhibitors in conjunction with nitrogen or a vacuum to achieve highly efficient corrosion protection of any metal part in different environments (vapor space and liquid). We will discuss new inhibitor formulations and protection principles that are recommended for rapid and sustained corrosion protection of internal metal surfaces of enclosures in industrial environments. These environments can contain acidic gasses and relative humidity up to 100%. The recommended solutions can increase the useful service life of equipment, increase time between failures and reduce time to repair.

Time-of-flight neutron measurements have been made at 20, 400 and 650oC on δ-processed Inconel 718 in order to measure the load sharing between the γ-phase matrix and the orthorhombic δ-phase. The strain response parallel and perpendicular to the applied stress was measured for seven γ-phase reflections and five δ-phase reflections. The latter were about 50 times weaker than the former suggesting a 2.0% concentration of the δ-phase. At all temperatures the δ-phase strain becomes strongly tensile parallel to the loading direction but also exhibits plastic deformation. However, the nature of the three orthorhombic strains changes with temperature.

Corrosion of pipeline flanges and valves is a major worldwide problem.These pipeline connections are highly susceptible to pitting and crevice corrosion, which is the primary cause of pipeline failure.Often, to reduce or eliminate the risk of leaks and the resultant problems (fire, explosions, environmental contamination, etc.), pipelines are taken out of operation.Many effective corrosion protection solutions exist, but none are universally applicable due to application limitations and/or cost.Over the last 10 years, we have developed different types of covers/systems that, when applied, provide efficient corrosion protection.This paper presents field trial test results over a one year period in a very harsh environment -at temperatures from -30 to +40°C and relative humidity higher than 50%.The new data demonstrates a high level of corrosion protection efficiency that allows to expand areas of flange savers application.This is an alternative, low-cost method which uses volatile corrosion inhibitors (VCI) to protect flanges, valves and welded joints from corrosion.

Abstract Corrosion of flanges, valves and welded joints are major problems in the Oil & Gas, Chemical Process, and other industries. This paper presents a summary of new cover designs, laboratory test results, and application experiences in highly corrosive environments. This paper also describes the efficiency and experiences of these new covers and systems using VCI protection in combination with desiccants. In addition to offering corrosion protection, these covers have the added advantage of fast installation and easy removal and cleanup. The results show that these covers provide increased efficiency and service life for corrosion protection of various types of flanges, valves, welded joints in outdoor and indoor environments.

Abstract Cathodic protection methods, coatings and corrosion inhibitors can be efficiently employed to inhibit the corrosion of steel in oil and water storage tanks. This paper describes new technology, which makes possible effective employment of different combinations of protection methods to prevent corrosion of the bottom and tops of the storage tanks.