ผลการค้นหา

Brinell Hardness Number

แปลว่า(english) The value of hardness of a metal on an arbitrary scale representing kg/mm2, determined by measuring the diameter of the impression made by a ball of given diameter applied under a known load. Values are expressed in Brinell Hardness Numbers, BHN

Backer (back-up plate)

แปลว่า(english) A “tool” or reinforcing part, which presses against the outer surface of an extrusion die, supporting it against the pressure of the extruding metal. The backer has an opening larger than the die aperture, allowing the extruded product to emerge without marring its soft surface.

Bismuth

แปลว่า(english) Chemical symbol Bi. A soft, course cystalline heavy metal with a silvery white color and pinkish tinge; usually produced as a by-product of copper,leaad and other metals. Has a thermal conductivity lower than all other metals except mercury. Used as alloying agent but leading use is in pharmaceuticals.

Billet

แปลว่า(english) (1) A semi-finished section hot rolled from a metal ingot, with a rectangular cross section usually ranging from 16 to 36 in., the width being less than twice the thickness. Where the cross section exceeds 36 in., the term “bloom” is properly but not universally used. Sizes smaller than 16 in. are usually termed “bars”; a solid semi-finished round or square product which has been hot worked by forging, rolling, or extrusion. (2) A semi-finished, cogged, hot rolled or continuous-cast metal product of uniform section, usually rectangular with radiused corners. Billets are relatively larger than bars.

Boil

แปลว่า(english) Agitation of a bath of metal caused by the liberation of a gas beneath its surface. May be deliberately induced by the addition of oxidizing material to a bath containing excess carbon. In the later case it is called a carbon boil and CO or CO2 are liberated.

Basic Oxygen Furnace (BOF)

แปลว่า(english) "WHAT A pear-shaped furnace, lined with refractory bricks, that refines molten iron from the blast furnace and scrap into steel. Up to 30% of the charge into the BOF can be scrap, with hot metal accounting for the rest. WHY BOFs, which can refine a heat (batch) of steel in less than 45 minutes, replaced open-hearth furnaces in the 1950s; the latter required five to six hours to process the metal. The BOF's rapid operation, lower cost and ease of control give it a distinct advantage over previous methods. HOW Scrap is dumped into the furnace vessel, followed by the hot metal from the blast furnace. A lance is lowered from above, through which blows a high-pressure stream of oxygen to cause chemical reactions that separate impurities as fumes or slag. Once refined, the liquid steel and slag are poured into separate containers. "

Box Annealing

แปลว่า(english) Annealing a metal or alloy in a sealed container under conditions that minimize oxidation. In box annealing a ferrous alloy, the charge is usually heated slowly to a temperature below the transformation range, but sometimes above or within it, and is then cooled slowly; this process is also called close annealing or pot annealing.

Box Annealing 2

แปลว่า(english) A process of annealing a ferrous alloy in a closed metal container, with or without packing materials, in order to minimize the effects of oxidation. The charge is normally heated slowly to a temperature below the transformation range, but occasionally above or within it, and then is slowly cooled.

Aging 1

แปลว่า(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.

Blasting (Blast Cleaning)

แปลว่า(english) A process for cleaning or finishing metal objects by use of an air blast or centrifugal wheel that throws abrasive particles against the surface of the work pieces. Small, irregular particles of steel or iron are used as the abrasive in grit blasting, and steel or iron balls in shot blasting.

Break Test (for tempered steel)

แปลว่า(english) A method of testing hardened and tempered high carbon spring steel strip wherein the specimen is held and bent across the grain in a vice-like calibrated testing machine. Pressure is applied until the metal fractures at which point a reading is taken and compared with a standard chart of brake limitations for various thickness ranges.

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.