时间：2011-03-11 23:11来源：蓝天飞行翻译 作者：admin 点击：次
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chrome nickel steel. An alloy of steel used for making many of the fittings and fasteners used in aircraft structure. Chrome nickel steels are the SAE 3xxx series. chrome pickling. A method of forming a hard oxide film on the surface of a piece of magnesium to protect it from corrosion. To form this film, the magnesium is soaked in a solution of potassium dichromate. Chrome pickling is also called dichromate conversion. The surface of the metal is converted into a dense oxide film. chrome plating. An electroplating process in which a thin film of chromium is plated on the surface of a steel part. There are two types of chrome plating: hard chrome and decorative chrome. Hard chrome is used to plate the inside walls of an engine cylinder to form a wear-resistant surface. Decorative chrome is used on such components as automobile bumpers to provide a durable, weather-resistant, and attractive surface. chrome vanadium steel. A very tough alloy of steel with chromium and vanadium. Chrome vanadium steel is used for making wrenches and other tools that require high strength and good impact resistance. chromic acid. An acid used for etching aluminum alloys to prepare them for painting. Chromic acid reacts with the aluminum to form a durable film on the surface that keeps oxygen away from the metal and inhibits the formation of corrosion. chromium. A lustrous, hard, steel-gray, metallic chemical element. Chromium’s symbol is Cr, its atomic number is 24, and its atomic weight is 51.996. Chromium is used to harden alloy steels and as an alloying agent to make corrosion-resistant steels. chronometric tachometer. An instrument used to measure the speed in revolutions per minute of the crankshaft of an aircraft reciprocating engine. A chronometric tachometer repeatedly counts the number of revolutions in a given period of time and displays the average speed on its dial. chuck (machine tool component). The device on a lathe or drill press used to hold either the material being worked or the machine tool used to work on the material. Chucks have three or more jaws to clamp and hold the material or the tool. chugging (gas turbine engine operating condition). A noise heard in a gas turbine engine caused by unstable airflow in the engine. The chugging noise is produced by a mild compressor stall. chute. A sloping channel used to allow objects or materials to slide from one level to a lower level. cigarette (ignition system component). A ceramic or synthetic rubber insulator used on the end of an ignition lead that attaches to a shielded spark plug. A steel coil spring on the end of the cigarette conducts the high voltage from the lead wire to the center electrode of the spark plug. circle. A closed plane figure with every point an equal distance from the center. A circle has the greatest area for its circumference of any enclosed shape. circle graph. A visual presentation of data in which the entire quantity is shown as a circle. Each portion of the data is shown as a segment of the circle. Circle graphs are also called pie charts, because all the data resembles a complete pie, and each individual portion resembles a slice of the pie. |
