ค้นเจอ 94 รายการ

Agglomerating Processes

แปลว่า(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.

Pozzolan (ASTM C 618)

แปลว่า(Concrete Engineering) A siliceous, or siliceous and aluminous material, which in itself possesses little or no cementitious value but will, in a finely divided form, such as a powder or liquid and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form permanent, insoluble compounds possessing cementitious properties.

Brinell Hardness Test

แปลว่า(english) A common standard method of measuring the hardness of materials. The smooth surface of the metal is subjected to indentation by a hardened steel ball under pressure. The diameter of the indentation, in the material surface, is then measured by a microscope and the hardness value is read from a chart or determined by a prescribed formula.

Water-Cement Ratio

แปลว่า(Concrete Engineering) The ratio of the amount of water, exclusive of that absorbed by the aggregates, to the amount of cement in a concrete mix. Typically expressed as percentage of water, by weight in pounds, to the total weight of portland cement, fly ash, and any other cementitious material, per cubic yard, exclusive of any aggregates.

Brinell Hardness Testing

แปลว่า(english) Method of determining the hardness of materials; involves impressing a hardened ball of specified diameter into the material surface at a known pressure (10-mm ball, 500-kg load for aluminum alloys). The Brinell hardness number results from calculations involving the load and the spherical area of the ball impression. Direct-reading testing are generally used for routine inspection of forgings, and as a heat treat control function.

Brazing

แปลว่า(english) Joining metals by fusion of nonferrous alloys that have melting points above 800 F (425C), but lower than those of the metals being joined. May be accomplished by a torch. Filler metal is ordinarily in rod form in torch brazing; whereas in furnace and dip brazing the work material is first assembled and the filler metal may then be applied as wire, washers, clips, bands, or may be bonded, as in brazing sheet.

Stiffness:

แปลว่า(english) This is a general term which may be applied to materials or structures. When a force is applied to a structure, there is a displacement in the direction of the force; stiffness is the ratio of the force divided by the displacement. High stiffness means that a large force produces a small displacement. When discussing the stiffness of a material, the concept is the same, except that stress substitutes for force, and strain substitutes for displacement; see modulus of elasticity.

Z-Mill

แปลว่า(english) The full name for z-mill is Sendzimir mill. A Z-mill operates with a very small diameter work roll, normally about 2 inches, backed up by a number of rolls in a pyramid-shaped stack. This roll set up allows you to exert extremely high forces through the work roll and yet keep the work roll from extreme flexing. The take-up roll on the Z-Mill also exerts a tension on the coil as it comes through the mill. The combination of high pressure and tension makes the mill capable of rolling material thin and flat.

Bend Test

แปลว่า(english) Various tests which is used to ascertain the toughness and ductility of a metal product, in which the material is bent around its axis and/ or around an outside radius. A complete test might specify such a bend to be both with and against the direction of grain. For testing, samples should be edge filed to remove burrs and any edgewise cracks resulting from slitting or shearing. If a vice is to be employed, then you must line the jaws with some soft metal, to permit a flow of the metal in the piece being tested.

AAC - Autoclaved Aerated Concrete

แปลว่า(Concrete Engineering) Exceptionally lightweight precast concrete with high thermal qualities and fire resistence. Suitable for cutting with ordinary hand tools. Mix design is composed of portland cement, sand or siliceous material, lime, gypsum, finely powdered aluminum, and water. Initial mix is a combination of portland cement, sand, lime and gypsum to produce a slurry. Finely powdered aluminum mixed into a paste is added prior to placement into large, rail-like forms. The finely powdered aluminum reacts with the alkaline components of the cement and lime to produce hydrogen gas, which increases the volume approximately five times producing a uniformly, dispersed cellular structure. Units are cut to required shape. Units are placed in an autoclave, an enclosed pressurized chamber, and steam cured at 3500 F. Approximately 80% of the ultimate volume consists of air voids.