(1) An iron mineral crystallizing in therhombohedral system; the most important oreof iron. (2) An iron oxide, Fe,O,, corrcsponding to an iron content of approximately 70%.

Evidence of plastic deformation in structural materials. Also called plastic flow or creep. See also flow.

The condition of being electrically separated from other metallic structures or the environment.

A linear imperfection in a crystalline array of atoms. Two basic types are recognized: (1) an edge dislocation corresponds to the row of mismatched atoms along the edge formed by an extra, partial plane of atoms within the body of a crystal; (2) a screw d ...

A chromate conversion coating produced on magnesium alloys in a boiling solution of sodium dichromate.

The coating, usually green, that forms on the surface of metals such as copper and copper alloys exposed to the atmosphere. Also used to describe the appearance of a weathered surface of any metal.

In a cathodic protection system, in electrically nonconductive material, such as a coating, plastic sheet or pipe that is placed between an anode and an adjacent cathode to avoid current wastage and to improve current distribution, usually on the cathode.

A change in dimensions directly proportional to and in phase with an increase or decrease in applied force.

Deforming metal plastically under conditions of temperature and strain rote that induce strain hardening. Usually, hut not necessarily, conducted at room temperature. Contrast with hot working.

The partial derivative of the total electrochemical free energy of a constituent with respect to the number of moles of this constituent where all factors are kept constant. It is analogous to the chemical potential of a constituent except that it include ...

Any process whereby a base metal or alloy is either (1) coated with another metal or alloy and heated to a sufficient temperature in a suitable environment or (2) exposed to a gaseous or liquid medium containing the other metal or alloy, thus causing diff ...

See principal stress (normal).

Imparting resistance to oxidation to an iron or steel surface by heating in aluminum powder at 800 to 1000

(1) Reduction of corrosion rate by shifting the corrosion potential of the electrode toward a less oxidizing potential by applying an external electromotive force. (2) Partial or complete protection of a metal from corrosion by making it a cathode, using ...

Provisional value for plane-strain fracture toughness.

The lowest value of oxidizing potential at which pits nucleate and grow. It is dependent on the test method used.

Any interruption in the normal physical structure or configuration of a part, such as cracks, laps, seams, inclusions, or porosity. A discontinuity may or may not affect the usefulness of the part.

The property of a material by virtue of which deformation caused by stress disappears upon removal of the stress. A perfectly elastic body completely recovers its original shape and dimensions after release of stress.

Plating with dummy cathodes.

A term generally applied to paints to describe holidays, holes, and skips in a film. Also used to describe shrinkage in castings and weld.