Welding Definitions
ACETONE:
A flammable, volatile liquid used in acetylene cylinders to dissolve and stabilize acetylene under high pressure.
ACETYLENE:
A highly combustible gas composed of carbon and hydrogen. Used as a fuel gas in the oxyacetylene welding process.
ACTUAL THROAT:
See THROAT OF FILLET WELD.
AIR-ACETYLENE:
A low temperature flare produced by burning acetylene with air instead of oxygen.
AIR-ARC CUTTING:
An arc cutting process in which metals to be cut are melted by the heat of the carbon arc.
ALLOY:
A mixture with metallic properties composed of two or more elements, of which at least one is a metal.
ALTERNATING CURRENT:
An electric current that reverses its direction at regularly recurring intervals.
AMMETER:
An instrument for measuring electrical current in amperes by an indicator activated by the movement of a coil in a magnetic field or by the longitudinal expansion of a wire carrying the current.
ANNEALING:
A comprehensive term used to describe the heating and cooling cycle of steel in the solid state. The term annealing usually implies relatively slow cooling. In annealing, the temperature of the operation, the rate of heating and cooling, and the time the metal is held at heat depend upon the composition, shape, and size of the steel product being treated, and the purpose of the treatment. The more important purposes for which steel is annealed are as follows: to remove stresses; to induce softness; to alter ductility, toughness, electric, magnetic, or other physical and mechanical properties; to change the crystalline structure; to remove gases; and to produce a definite microstructure.
ARC BLOW:
The deflection of an electric arc from its normal path because of magnetic forces.
ARC BRAZING:
A brazing process wherein the heat is obtained from an electric arc formed between the base metal and an electrode, or between two electrodes.
ARC CUTTING:
A group of cutting processes in which the cutting of metals is accomplished by melting with the heat of an arc between the electrode and the base metal. See CARBON-ARC CUTTING, METAL-ARC CUTTING, ARC-OXYGEN CUTTING, AND AIR-ARC CUTTING.
ARC LENGTH:
The distance between the tip of the electrode and the weld puddle.
ARC-OXYGEN CUTTING:
An oxygen-cutting process used to sever metals by a chemical reaction of oxygen with a base metal at elevated temperatures.