| 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. |
| Acid-Process | (english) A process of making steel, either Bessemer, open-hearth or electric, in which the furnace is lined with a siliceous refractory and for which low phosphorus pig iron is required as this element is not removed. |
| Acme Thread | (english) A screw thread having a 29 degree included angel. Used largely for feed and adjusting screws on machine tools. |
| ACTUATOR | (english) A device for converting hydraulic energy into mechanical energy, i.e., a motor or cylinder. |
| Adapti Investment Casting Process | (english) A lost wax process employing one of three methods; centrifugal, vacuum or gravity-pouring casting. |
| 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. |
| AFS Tests | (english) A number of standard tests determined by American Foundrymen's Society to evaluate molding and core sands. |
| 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. |
| Agglomerating Processes | (english) "Fine particles of limestone (flux) and iron ore are difficult to handle and transport because of dusting and decomposition, so the powdery material usually is processed into larger pieces. The raw material's properties determine the technique that is used by mills. 1) SINTER Baked particles that stick together in roughly one-inch chunks. Normally used for iron ore dust collected from the blast furnaces. 2) PELLETS Iron ore or limestone particles are rolled into little balls in a balling drum and hardened by heat. 3) BRIQUETTES Small lumps are formed by pressing material together. Hot Iron Briquetting (HBI) is a concentrated iron ore substitute for scrap for use in electric furnaces. |
| Aging 1 | (english) A change in the properties of certain metal and alloys (such as steel) that occurs at ambient or moderately elevated temperatures after a hot working heat treatment or cold working operation. Typical properties impacted are hardness, yield strength, tensile strength, ductility, impact value, formability, magnetic properties, etc. See also Non-aging. |