Corrosion Terminology - W's

wash primer—a thin, inhibiting, or passivating primer, usually formulated with chromate or phosphate pigment in a synthetic resin (e.g., polyvinyl butyral) binder.

water cleaning—use of pressurized water discharged from a nozzle to remove unwanted matter from a surface.

water jetting—use of standard jetting water discharged from a nozzle at pressures of 70 MPa (10,000psig) or greater to prepare a surface for coating or inspection.

weight coating—an external coating applied to a pipeline to counteract buoyancy.

weld—join two or more pieces of material by applying heat and/or pressure with or without filler material, to produce a union through localized fusion of the substrates and solidification across the interfaces.

weld decay—(not a preferred term) inter granular corrosion, usually of stainless steels or certain nickel alloys, that occurs as the result of sensitization in the heat-affected zone during the welding operation.

weldment(1) an assembly of components joined by welding. (2) [for metals] the weld metal, the heat-affected zone, and the adjacent parent metal.

weld metal—that portion of a weldment that has been molten during welding.

wet film gauge—device for measuring wet film thickness of a coating.

wetfilm thickness—the thickness of a coating measured immediately after application before any appreciable solvent has evaporated or drying has taken place.

wet sponge test—a low-voltage electrical test suitable for detecting holidays in thin-film coatings.

white cast iron—cast iron that displays a white fracture surface.

white metal blast cleaned surface—an abrasive blast cleaned steel surface that is free of all visible contaminants, foreign matter, and staining. [See NACE No.1/SSPC-SP 5 for detailed specification.]

white rust—the white powdery corrosion product that can form on zinc, zinc-coated, or aluminum-based alloy surfaces. [See rust.]

working electrode—the test or specimen electrode in an electro-chemical cell.

wrinkling—formation of a surface appearance in a coating resembling the skin of a dried prune, usually caused by application shortcomings.

wrought—describes a metal in the solid condition formed to a desired shape by working (e.g.,rolling, extruding, forging), usually at an elevated temperature.