The potential for structural alloys to undergo environmentally assisted cracking in molten salts is relatively unexplored due to their limited industrial application. However, fluoride salts are of prime interest to many advanced reactors including the Kairos Power FHR reactors. Table I summarizes literature studies of EAC in molten fluoride salts. For the ten studies shown, seven are for Ni-Mo-Cr family of alloys (INOR-8 / Hastelloy N or variants) that were used in the Molten Salt Reactor Experiment (MSRE), two studies investigate austenitic stainless steels, and there is one report of EAC in oxygen free high conductivity (OFHC) copper.
There is considerable interest in molten halide salts for several applications including thermal storage and next generation nuclear reactors. While molten salt as a working fluid and/or fuel media offers advantages, salt compatibility with structural and functional materials is a concern. Various reports in the literature suggest that chloride and fluoride salts can be highly corrosive to structural alloys but do not always clearly describe how the salt was handled and dried/purified prior to and during the corrosion experiment.
The required electrical power in the United States has led the utilities and the US Nuclear Regulatory Commission to evaluate second license renewals for operating light-water reactors, and some extensions have already been reviewed for extended operation to 80 years. As these plants were licensed to operate for 40 years with options for additional 20 year extensions, the extended operation raised questions in terms of materials performance under extreme conditions and extended time. The effects of prolonged irradiation must be understood and evaluated to predict and ensure the reliability of plant components.
Development of new oil and gas fields is likely to involve sour reserves to an increasing degree. Sour
production often brings about difficulties in terms of asset integrity, related particularly to corrosion
mitigation. Employing corrosion resistant alloys implies a considerable escalation in investment costs. On this basis the use of carbon steel and CO2/H2S corrosion inhibition remains a highly desirable
External corrosion on offshore O&G platforms is one of the biggest threats to asset integrity and its management is a large operational expense. Many operators now implement risk-based assessment (RBA) programs where all equipment is assessed periodically with the aim to reduce operational costs while maintaining integrity. Regulatory codes for offshore platforms in the GoM require a visual inspection of all pressure equipment and piping every five-years. In practice, this can equate to approximately 20% of equipment being inspected per year on a large-sized offshore platform (i.e., a topside weight of around 10,000 tons), with a rolling five-year inspection plan to balance the inspection workload evenly through time.
A vessel docked for maintenance is a vessel out of service. For military forces, this significantly affects the readiness of that force, its ability to respond quickly and appropriately to a developing situation. It is for this reason that the United States Navy continues to search for and invest in innovations that improve maintenance turn-around times as well as innovations that keep vessels in service for longer periods of time. In large-scale construction and manufacturing industries such as shipbuilding and naval maintenance, coating removal is an essential but time-consuming process required for constructing and maintaining vessels and other structures.
This paper details a precision process for removal of coatings and preparation of the metal surface underneath for optimal chemical adhesion without damaging the metal surface or the surface profile. A precision process is required for removal of coatings around corroded surfaces, potentially defective structures, or thin-walled ligaments where abrasive removal procedures will damage the substrate. In these cases, removing metal will worsen or cause a defect where replacement is expensive. A precision tool that can safely remove the coating, allow for inspection, and enhance adhesion for recoating is needed. This type of tool would enhance existing repair technologies and eliminate the immediate need for replacement.
Oil and gas production in a CO2 saturated environment is known to lead to corrosion due to dissolved carbonic acid. However, when the conditions are favorable, a protective FeCO3 layer can also form which reduces the material degradation of the underlying steel by up to ten or a hundred times.1 The formation of FeCO3 is possible via the reaction shown in equation 1.
Coating degradation on Army ground systems represents a significant maintenance cost and effort. The objective of this proposed work is to develop a predictive model for coating degradation and subsequent substrate corrosion on Army ground assets. Provided with a better understanding of the root causes, steps can be taken to reduce corrosion impacts on Army materiel.
Variability of operation and practices can lead to mechanical integrity issues of equipment. A similar case was observed when an external UT survey was conducted on a biocide storage tank that showed localized areas of metal loss in the tank wall. The tank was opened for inspection and extensive internal corrosion damage was observed mainly in the form of large isolated pits. Three potential corrosion mitigation options were evaluated: upgrading the tank material from coated carbon steel to 316 stainless steel, installing a non-metallic lining, or keeping using the coated carbon steel and changing the operation practices. Each mitigation option was evaluated based integrity, feasibility, and economic factors. It was found that keeping the coated carbon steel and adjusting the operation practices can ensure the integrity of the tank while lowering the required economical investment. As such, a new operation manual was issued for the biocide storage tanks that ensured that the corrosion inducing environments are avoided.
The brake system is a core component of cars, motorbikes, bikes, airplanes etc.. Its main task is to modulate the speed of moving vehicles by converting the kinetic energy into heat.1,2 In the case of modern cars or motorbikes, the speed modulation can be performed by using the so-called disc-brake system.1,2,3,4,5,6 This generates the braking torque by forcing two brake pads against a disc by the means of a caliper.2,3,5,6 In the case of cars, the disc and the caliper are enclosed within each wheel and, as a consequence, can be exposed to corrosion phenomena, mostly related with atmospheric or environmental conditions.1,3,7,8