| Accordion Reed Steel | (english) Hardened, tempered, polished and blued or yellow flat steel with dressed edges. Carbon content about 1.00. Material has to possess good flatness, uniform hardness and high elasticity. |
| Acid | (english) 1) A solution or liquid with a pH less than 7, 2) term applied to slags, refractors, and minerals containing a high percentage of silica. |
| Acid Brittleness (Pickling Brittleness) | (english) Brittleness resulting from pickling steel in acid; hydrogen, formed by the interaction between iron and acid, is partially absorbed by the metal, causing acid brittleness. |
| Acid-Brittleness | (english) Brittleness resulting from pickling steel in acid; hydrogen, formed by the interaction between iron and acid, is partially absorbed by the metal, causing acid brittleness. |
| Activation | (english) The changing of the passive surface of a metal to a chemically active state. Contrast with passivation. |
| Addendum | (english) That portion of a gear tooth that extends from the pitch circle to the outside diameter. |
| Addition Agent | (english) 1) Any material added to a charge of molten metal in bath or ladle to bring alloy to specifications, 2) reagent added to plating bath. |
| Adeline Steelmaking Process | (english) Method of producing a precision casting of steel or steel alloys using aluminolthermic process and lost wax, followed by centrifugal action. |
| Aecm, Ae1, and Ae3 | (english) Equilibrium transformation temperatures in steel. |
| Age Hardening | (english) Hardening by aging, usually after rapid cooling or cold working. The term as applied to soft, or low carbon steels, relates to a wide variety of commercially important, slow, gradual changes that take place in properties of steels after the final treatment. These changes, which bring about a condition of increased hardness, elastic limit, and tensile strength with a consequent loss in ductility, occur during the period in which the steel is at normal temperatures. |