The invention relates to a method and system for preventing corrosion of at least one metallic structure in an electrolyte medium, comprising applying a superimposed time-varying frequency electromagnetic wave to the structure, the method comprising the steps of generating a superimposed time-varying frequency electromagnetic wave (DAC wave) where an AC driving signal with time-varying frequency is riding on a DC output with a predefined DC bias voltage, transmitting the DAC wave current to one or more emitters, emitting the DAC wave via the one or more emitters, placing the one or more emitters at a spaced distance from the metallic structure, subjecting the metallic structure to the DAC wave current, controlling the negative return current of the DAC wave from the metallic structure, such that the DAC wave is distributed across the structure surface and directly excites a target region of the metallic structure, and wherein the excitation induces a flow of ionic current having a DC component travelling in a pulsating and time-varying manner in the target region and effects induced vibration of electrons and molecules in the target region. The method and the system of the invention significantly reduce capital costs and require very low energy, they avoid environmentally unfriendly final products, and are able to result in effective corrosion protection of metallic structures in different surrounding conditions.

The disclosure relates to a method and system for treating ballast water and ballast water treatment systems in order for treatment effects to be carried out, such as controlling the transportation of undesirable and invasive marine organisms. In particular, the disclosure relates to methods and systems for applying a superimposed time-varying frequency electromagnetic wave comprising both AC and DC components in a pulsating manner to ballast water within a ballast water treatment system.

A coated structure with a monitoring system, the structure comprising a base having a base surface, a coating joined to the base surface in a base interface and extending in a thickness direction to an outer coating surface, a sensor comprising at least one electrode embedded in the coating, an I/O device configured to generate an input signal in the sensor and to read an output signal from the sensor, a data logger configured to log the output signal from the I/O device, and a computer unit configured to use the logged signal from the data logger. To provide improved information related to the condition of the structure or coating, the computer unit is configured to determine at least two separate indexes, each index related to a property of the coating or the structure.

A metallic object to be protected from corrosion, such as a steel automobile body panel, is connected to an electron source as a cathode. An electrically isolating coating is disposed on the metallic object. A covering anode is applied onto the electrically isolating coating. The covering anode is electrically conductive. An electrode is connected to the covering anode and to the electron source. Damage to the covering anode and the electrically isolating coating creates a location for electrolyte to collect to create an electrochemical cell and activate cathodic protection to prevent corrosion of the metallic object.

The present invention relates to improvement of the outside anticorrosive treatment of ductile cast iron piping members, through the development of a Pseudo Alloy metallic film along with modified paint on the external surface, more particularly the present disclosure relates to the improved corrosion resistant to ductile cast iron piping members, specially when used in buried condition, the coating method that can form an anticorrosion pseudo metal alloy layer in the peripheral surface along with a modified Cashew Nut Shell Liquid (CNSL) paint.

In this flat extruded aluminum multi-port tube, the corrosion-resistance, at inner surfaces of a plurality of flow passages independently and parallelly extending in the tube axial direction, is effectively enhanced. In a flat extruded aluminum multi-port tube 10 formed by an extrusion by employing an aluminum tube material and an aluminum sacrificial anode material having an electrochemically lower potential than the aluminum tube material, the aluminum sacrificial anode material is exposed to form a sacrificial anode portion 18 at least in a part of an inner circumferential portion in each of the plurality of flow passages 12.

An automotive member or a feed oil pipe includes: a member made of a ferritic stainless steel containing predetermined components containing 10.5% to 18.0% of Cr in mass %; a metal fitting made of an aluminized stainless steel sheet, the metal fitting being attached to the member; and a gap structure defined between the member and the metal fitting, the gap structure being exposed to a chloride environment, where the metal fitting has an Al-plating weight per unit area of 20 g/m.sup.2 or more and 150 g/m.sup.2 or less on a surface corresponding to a gap of the gap structure, and surfaces of the metal fitting and the non-aluminized member other than the gap are coated with a cation electrodeposition coating film having a thickness of 5 m to 35 m.

An enhanced anode includes a modulated body which improves anode current output efficiency by maximizing the surface area to increase surface area to weight ratio. A toroidally modulated embodiment of the enhanced anode enlarges surface area by 48 percent increasing current output efficiency by 48 percent, only increases weight by three percent, and improves surface/weight ratio 44 percent, compared to know cylindrical anodes. The enhanced anode is preferably made from cast iron or other suitable materials (e.g. magnesium, zinc, aluminum) as well, and the design of the improved anode is applicable to galvanic cast anodes in general. The enhanced anode is suitable for molding and casting and does not increase production costs.

A coated structure with a monitoring system includes a base having a base surface, a coating joined to the base surface in a base interface and extending in a thickness direction to an outer coating surface, a sensor comprising at least one electrode embedded in the coating, an I/O device configured to generate an input signal in the sensor and to read an output signal from the sensor, a data logger configured to log the output signal from the I/O device, and a computer unit configured to use the logged signal from the data logger. To provide improved information related to the condition of the structure or coating, the computer unit is configured to determine at least two separate indexes, each index related to a property of the coating or the structure.

Provided are systems and methods for preventing corrosion, and lead and iron contamination in potable water piping systems comprising lead, non-electrically conducting, and/or iron pipes. A sacrificial/potential anode, made of a material, such as a metal or metal alloys less noble than iron, e.g., zinc, aluminum, magnesium, and/or alloys thereof, is electrically attached to the potable water piping system. Alternatively, an active cathodic corrosion prevention system may be used. The active cathodic corrosion protection system comprises an independent source of DC power, a voltage controller and a non-sacrificial or a sacrificial/potential grounding anode. The negative terminal of the voltage controller is connected to the potable water piping system. The interior surface of the lead and/or iron pipe is maintained at a voltage and/or potential above the reduction potential of the redox reactions between the disinfection chemicals and the interior surfaces of the lead and iron pipes.