Technical Data

Metallurgical Terms

Orange Peel Effect.

An effect which arises from the roughening of the surface due to the coarse grain size, when steel sheets are stretched beyond their elastic limit. Also applied to the roughening of the surface of hard rolls arising from differential wear.

Orientation.

The direction of the axis of a crystal in relation to a certain surface or line; for example, the polished surface of a cleavage plane.

Overheating.

Heating a metal or alloy below the temperature at which burning occurs, but to such a high temperature that deterioration of properties results. The condition is characterized by the fracture which shows dull facets and by the appearance of a characteristic network on etching polished sections with sulphuric/nitric acid reagent. Steels which have been overheated cannot be rectified by any commercially applicable method.

Oxygen.

A chemically active gas used by the steel industry in large quantities for steelmaking, welding and cutting. Oxygen may be injected into the liquid steel to oxidize carbon and other elements. (See also Basic Oxygen Process).