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Inertial Force:

(english) A fictitious force used for convenience in visualizing the effects of forces on bodies in motion. For an accelerating body, the inertial force is considered as a body force whose resultant acts at the object's center of gravity in a direction opposite the acceleration. The magnitude of the force is the mass of the object times the magnitude of the acceleration.

Greenhouse gases

(Environmental Engineering) Gases which trap solar radiation. Of the solar energy entering the earth's atmosphere a portion is reflected back and a portion penetrates onto the earth's surface. The portion reflected back from the earth's surface is at a different wavelength that when it entered. Carbon dioxide and other gases, which pass solar radiation, absorb this reflected radiation, increasing the earth's temperature. This is much like a greenhouse, hence the name.

Carbonation

(Concrete Engineering) 1) Reaction between the products of portland cement (soluble calcium hydroxides), water and carbon dioxide to produce insoluble calcium carbonate (efflorescence). 2) Soft white, chalky surface dusting of freshly placed, unhardened concrete caused by carbon dioxide from unvented heaters or gasoline powered equipment in an enclosed space. 3) Carbonated, dense, impermeable to absorption, top layer of the surface of concrete caused by surface reaction to carbon dioxide. This carbonated layer becomes denser and deeper over a period of time. 4) Reaction with carbon dioxide which produces a slight shrinkage in concrete. Improves chemical stability. Concrete masonry units during manufacturing may be deliberately exposed to carbon dioxide after reaching 80% strength to induce carbonation shrinkage to make the units more dimensionally stable. Future drying shrinkage is reduced by as much as 30%.

Support:

(english) A support contributes to keeping a structure in place by restraining one or more degrees of freedom. In a structural model, supports represent boundary entities which are not included in the model itself, e.g., foundations, abutments, or the earth itself. For each restrained translation degree of freedom at a support, there is a corresponding reaction force; for each restrained rotation degree of freedom, there is a reaction moment.

Boron (chemical symbol B)

(english) Element N. 5 of the periodic system. Atomic weight 10.82. It is gray in color, ignites at about 1112 (degrees) F. and burns with a brilliant green flame, but its melting point in a non-oxidizing atmosphere is about 4000 (degrees) F. Boron is used in steel in minute quantities for one purpose only- to increase the hardenability as in case hardening and to increase strength and hardness penetration.

Brinell Hardness Testing

(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.

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.

Batch Anneal

(english) The process by which a large, stationary stack of steel coils (4 coils high) is subjected to a long heat-treating cycle. This process enables the cold-rolled sheet to fully recrystallize into the softest possible product conforming to customer specifications. Controlling the recrystallization process makes a fine-grained microstructure easy to obtain, and minimizes the tendencies for retention of directional properties of the rolled steel which could produce undesirable shapes in the stamping of a cylindrical part such as a can. Also see Anneal and Continuous Anneal.

Z-Mill

(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.

Billet

(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.

Brown Sharp Gages

(english) A standard series of sizes refered to by numbers, in which the diameter of wire or thickness of sheet metal is generally produced and which is used in the manufacture of brass, bronze, copper, copper-base alloys and aluminum. These gage numbers have a definite relationship to each other. In this system, the decimal thickness is reduced by 50% every six gage numbers- while temper is expressed by the number of B&S gage numbers as cold reduced in thickness from previous annealing. For each B&S gage number in thickness reduction, where is assigned a hardness value of 1/4 hard.

Black Plate

(english) A light weight or a thin uncoated steel sheet or strip so called because of its dark oxide coloring prior to pickling. It is manufactured by two different processes. (1) Form sheet bar on single stand sheet mills or sheet mills in tandem. This method is now almost obsolete. (2) On modern, high speed continuous tandem cold reduction mills from coiled hot rolled pickled wide strip into ribbon wound coils to finished gage. Sizes range from 12 to 32 in width, and in thicknesses from 55 lbs. to 275 lbs. base box weight. It is used either as is for stampings, or may be enameled or painted or tin or terne coated.

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