A hybrid sacrificial galvanic anode, an anodic system including the hybrid sacrificial anode, and a method of cathodically protecting steel reinforcement in concrete structures is provided. The hybrid anode provides initial steel polarization followed by long term galvanic protection without the use of batteries or external power supplies.

A corrosion protection anode using an external power supply in which a reinforcing layer formed of a fiber base material is laminated with an adhesive layer on one surface of a conductive layer formed of a graphite sheet, and an electrolyte layer of an electrolyte-containing resin formed in a sheet shape and having adhesive power such that the layer is capable of being adhered to the conductive layer and to a surface layer of an object to be protected from corrosion is adhered by the adhesive power thereof to the other surface of the conductive layer, wherein the conductive layer always has a resistance value of 4 or less between any two points on the surface thereof on a side that comes into contact with the electrolyte layer.

A corrosion protection anode using an external power supply in which a reinforcing layer formed of a fiber base material is laminated with an adhesive layer on one surface of a conductive layer formed of a graphite sheet, and an electrolyte layer of an electrolyte-containing resin formed in a sheet shape and having adhesive power such that the layer is capable of being adhered to the conductive layer and to a surface layer of an object to be protected from corrosion is adhered by the adhesive power thereof to the other surface of the conductive layer, wherein the conductive layer always has a resistance value of 4 or less between any two points on the surface thereof on a side that comes into contact with the electrolyte layer.

The present invention is a hydraulic excavation and delivery device capable of hydraulically removing soil overburden from a buried structure, like a pipeline, and delivering an article, such as an electro-mechanical connector for attachment to the buried structure. Hydraulic excavation is achieved by directing a stream of fluid at soil adjacent to and inside an open bottom region of the device to simultaneously dislodge adjacent soil, suspend dislodged soil in the accumulating fluid and form a pit that the device may fit within. Delivery of article is achieved by: (1) loading an article into the tool; (2) advancing the device toward the buried structure by deepening the pit without significant failure (slumping or sagging) of the pit walls until a portion of the buried structure is exposed and within the device; (3) landing the device on the exposed portion of the structure; (4) fixing the article to the exposed portion of the structure; and (5) releasing the article from the device.

An apparatus may mount an in-stream, continuous contact, visible, sacrificial anode in a fluid passage for the electrolytic corrosion protection. The apparatus may function to protect heat exchangers and/or other metallically connected system components that share contact with electrolytically active fluids. The apparatus may consist of an in-line anode cartridge including a collar body and a viewing port. The apparatus may include a site glass and compression fittings which seals the device causing corrosive fluids to flow past a sacrificial anode. The apparatus may include a visual indicator and an elastically compressed member (e.g., spring) which facilitate continuous metallic/electrical contact and inspection of the anode through the viewing port without system shut down or disassembly. The elastically compressed member and gauge assembly fills the view-ports with a bright indicator as the anode dissolves and the elastically compressed member expands. The apparatus improves inspection, replacement and effectiveness of sacrificial anodes in electrolytically corrosive environments.

A method is provided for reducing the corrosion rate of surfaces of formed magnesium or magnesium alloy articles in which the formed surface contains small embedded particles of iron. By exposing the iron particle-containing formed surface to an acidic, aqueous solution comprising alkali metal fluoride ions at a temperature of between 20 C. and 30 C., an adherent passivating layer of MgF.sub.2 is formed. Further, such exposure to the acidified, aqueous, fluoride ion-containing solution reduces or eliminates the concentration of cathodic, corrosion-promoting, iron-containing particles on the article surface as the magnesium fluoride layer is being formed. The development of the passivating layer reduces corrosion in a water-containing environment, and even if the passivating MgF.sub.2 layer is breached, the reduction in surface iron-containing particles reduces the inherent corrosion rate of the article.

A method is provided for reducing the corrosion rate of surfaces of formed magnesium or magnesium alloy articles in which the formed surface contains small embedded particles of iron. By exposing the iron particle-containing formed surface to an acidic, aqueous solution comprising alkali metal fluoride ions at a temperature of between 20 C. and 30 C., an adherent passivating layer of MgF.sub.2 is formed. Further, such exposure to the acidified, aqueous, fluoride ion-containing solution reduces or eliminates the concentration of cathodic, corrosion-promoting, iron-containing particles on the article surface as the magnesium fluoride layer is being formed. The development of the passivating layer reduces corrosion in a water-containing environment, and even if the passivating MgF.sub.2 layer is breached, the reduction in surface iron-containing particles reduces the inherent corrosion rate of the article.

Sacrificial anodes for installing in an ionically conductive medium at an installation site containing metal requiring cathodic protection are formed by locating anode cores in a tray having dividing members defining a row of side by side chambers with each chamber containing a respective one of the anode cores and casting into the receptacle a covering mortar for the anode cores with each anode core receiving a coating at least partly surrounding the anode core with the connecting wire exposed. The mortar is cast to form frangible bridges between each anode and the next. The trays are stacked and transported to the site where the installer separates and individually installs the anodes into the medium.

A sacrificial galvanic anode, an anodic assembly including the sacrificial anode, and a method of cathodically protecting steel reinforcement in concrete structures from corrosion is provided. The sacrificial galvanic anode comprises at least one sacrificial metal helical coil. The galvanic anode is easily fabricated and occupies a minimum volume within a steel reinforced concrete structure while providing maximum surface area for sacrificial corrosion.

The present invention relates to a method for impregnating concrete with a non-aqueous electrolyte characterized in that an electric field is applied between electrodes mounted on the concrete surface and/or embedded in the concrete such that the non-aqueous electrolyte migrates into the concrete. Preferably, lithium ions are dissolved in the non-aqueous electrolyte.