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C

Cake
A copper ingot rectangular in cross section intended for rolling.

Camber
(1) Deviation from edge straightness usually referring to the greatest deviation of side edge from a straight line. (2) Sometimes used to denote crown in rolls where the center diameter has been increased to compensate for deflection cause by the rolling pressure.

Camber or Bow
Edgewise curvature. A lateral departure of a side edge of sheet or strip metal from a straight line.

Camera Shutter Steel
Hardened, tempered and bright polished extra flat and extra precision rolled. Carbon content 1.25 - Chromium .15.

Canning
A dished distortion in a flat or nearly flat surface, sometimes referred to as oil canning.

Capped Steel
Semikilled steel cast in a bottle-top mold and covered with a cap fitting into the neck of the mold. The cap causes to top metal to solidify. Pressure is built up in the sealed-in molten metal and results in a surface condition much like that of rimmed steel.

Carbide
A compound of carbon with one or more metallic elements.

Carbon
Chemical symbol C. Element No. 6 of the periodic system; atomic weight 12.01; has three allotropic modifications, all non-metallic. Carbon is present in practically all ferrous alloys, and has tremendous effect on the properties of the resultant metal. Carbon is also an essential component of the cemented carbides. Its metallurgical use, in the form of coke, for reduction of oxides, is very extensive.

Carbon Equivalent
Referring to the rating of weld-ability, this is a value that takes into account the equivalent additive effects of carbon and other alloying elements on a particular characteristic of a steel. For rating of weld-ability, a formula commonly used is: CE = C + (Mn/6) + [(Cr + Mo + V)/5] + [(Ni + Cu)/15].

Carbon Free
Metals and alloys which are practically free from carbon.

Carbon Potential
A measure of the capacity of an environment containing active carbon to alter or maintain, under prescribed conditions, the carbon concentration in a steel.

Carbon Range
In steel specifications, the carbon range is the difference between the minimum and maximum amount of carbon acceptable.

Carbon Restoration
Replacing the carbon lost in the surface layer during previous processing by carburizing this layer to substantially the original carbon level.

Carbon Steel
Common or ordinary steel as contrasted with special or alloy steels, which contain other alloying metals in addition to the usual constituents of steel in their common percentages. (2) Steel containing carbon up to about 2% and only residual quantities of other elements except those added for deoxidization, with silicon usually limited to 0.60% and manganese to about 1.65%. Also termed plain carbon steel, ordinary steel, and straight carbon steel. (3) A steel containing only residual quantities of elements other than carbon, except those added for deoxidization or to counter the deleterious effects of residual sulfur. Silicon is usually limited to about 0.60% and manganese to about 1,65%. Also termed plain carbon steel, ordinary steel, straight carbon steel.

Carbonitriding
Introducing carbon and nitrogen into a solid ferrous alloy by holding above Ac1 in an atmosphere that contains suitable gases such as hydrocardons, carbon monocide, and ammonia. The carbonitrided alloy is usually quench hardened.

(2) A case hardening process in which a suitable ferrous material is heated above the lower transformation temperature in a gaseous atmosphere having a composition that results in simultaneous absorption of carbon and nitrogen by the surface and, by diffusion, creates a concentration gradient. The process is completed by cooling at a rate that produces the desired properties in the work piece.

Carburizing
A process in which an austenitized ferrous material is brought into contact with a carbonaceous atmosphere having sufficient carbon potential to cause absorption of carbon at the surface and, by diffusion, create a concentration gradient.

(2)Introducing carbon into a solid ferrous alloy by holding above Ac1 in contact with a suitable carbonaceous material, which may be a solid, liquid, or gas. The carburized alloy is usually quench hardened.

Carburizing (Cementation)
Adding carbon to the surface of iron-base alloys by absorption through heating the metal at a temperature below its melting point in contact with carbonaceous solids, liquids or gases. The oldest method of case hardening.

Cartridge Brass
70% copper 30% zinc. This is one of the most widely used of the copper-zinc alloys; it is formable and ductile and possesses excellent cold-working, poor hot working and poor machining properties. Rated excellent for soft-soldering; good for silver alloy brazing or oxyacetylene welding and fair for resistance of carbon arc welding. The alloy develops high tensile strength with cold-working. Temper is obtained by cold rolling.

Case
In a ferrous alloy, the outer portion that has been made harder than the inner portion, or core.

Case Hardening
Carburizing and subsequently hardening by suitable heat-treatment, all or part of the surface portions of a piece of iron-base alloy.

(2) Hardening a ferrous alloy so that the outer portion, or case, is made substantially harder than the inner portion, or core. Typical processes used for case hardening are carburizing, cyaniding, carbonitriding, nitriding, induction hardening, and flame hardening.

Case Hardening
A generic term covering several processes applicable to steel that change the the chemical composition of the surface layer by absorption of carbon or nitrogen, or a mixture of the two, and, by diffusion, create a concentration gradient.

Cast
(1) A term indicating in the annealed state as Cast Spring Steel Wire. (2) In reference to Bright or Polished Strip Steel or Wire, the word cast implies discoloration as a shadow. (3) A term implying a lack of straightness as in a coil set.

Cast Iron
Iron containing more carbon than the solubility limit in austenite (about 2%).

Cast Steel
Steel in the form of castings, usually containing less than 2% carbon.

(2) Any object made by pouring molten steel into molds.

Casting
(1) An object at or near finished shape obtained by solidification of a substance in a mold. (2) Pouring molten metal into a mold to produce an object of desired shape.

Cavitation
The formation and instantaneous collapse of innumerable tiny voids or cavities within a liquid subjected to rapid and intense pressure changes. Cavitation produced by ultrasonic radiation is sometimes used to give violent localized agitation. That caused by severe turbulent flow often leads to cavitation damage.

Cavitation Damage
Wearing away of metal through the formation and collapse of cavities in a liquid.

Cementation
(1) Introduction of one or more elements into the outer layer of a metal object by means of diffusion at high temperature. (2) An obsolete process used to convert wrought iron to blister steel by carburizing. Wrought iron bars were packed in sealed chests with charcoal and heated at about 2000 F (1100 C) for 6 to 8 days. Cementation was the predominant method of manufacturing steels particularly high-carbon tool steels, prior to the introduction of the bessemer and open-hearth methods.

Cementite
A compound of iron and carbon known as Iron carbide, which has the approximate chemical formula Fe3C containing 6.69% of carbon. Hard and brittle, it is the hard constituent of cast iron, and the normal form in which carbon is present in steel. It is magnetizable, but not as readily as ferrite.

(2) A compound of iron and carbon, known chemically as iron carbide and having the approximate chemical formula Fe3C. It is characterized by an orthorhombic crystal structure. When it occurs as a phase in steel, the chemical composition will be altered by the presence of manganese and other carbide-forming elements.

(3) A metastable carbide, with composition Fe3C and orthorhombic crystal structure, having limited substitutional solubility for the carbide-forming elements, notably manganese.

Centrifugal Casting
A casting made by pouring metal into a mold that is rotated or revolved.

Ceramic Tools
Cutting tools made from fused, sintered, or cemented metallic oxides.

Chafery
A charcoal-fired furnace used in early iron making processes to reheat a bloom of wrought iron for forging to consolidate the iron and expel entrapped slag.

(2) A beveled surface to eliminate an otherwise sharp corner. (2) A relieved angular cutting edge at a tooth corner.

Charcoal Tin Plate
Tin Plate with a relatively heavy coating of tin (higher than the Coke Tin Plate grades).

Charpy Test
A pendulum-type single-blow impact test in which the specimen usually notched, is supported at both ends as a simple beam and broken by a falling pendulum. The energy absorbed, as determined by the subsequent rise of the pendulum, is a measure of impact strength or notch toughness.

Chatter Marks
Parallel indentations or marks appearing at right angles to edge of strip forming a pattern at close and regular intervals, caused by roll vibrations.

Chemical Milling
Removing metal stock by controlled selective chemical etching.

Chemical Polishing
Improving the specular reflectivity of a metal surface by chemical treatment.

Chipping
A method for removing seams and other surface defects with chisel or gouge so that such defects will not be worked into the finished product. Chipping is often employed also to remove metal that is excessive but not defective. Removal of defects by gas cutting is known as deseaming or scarfing.

Chromadizing (Chromodizing, Chromatizing)
Forming an acid surface to improve paint adhesion on aluminum or aluminum alloys, mainly aircraft skins, by treatment with a solution of chromic acid.

Chromium
Chemical symbol Cr. Element No. 24 of the periodic system; atomic weight 52.01. It is of bright silvery color, relatively hard. It is strongly resistant to atmospheric and other oxidation. It is of great value in the manufacture of Stainless Steel as an iron-base alloy. Chromium plating has also become a large outlet for the metal. Its principal functions as an alloy in steel making; (1) increases resistance to corrosion and oxidation (2) increases harden-ability (3) adds some strength at high temperatures (4) resists abrasion and wear (with high carbon).

Chromium-Nickel Steel
Steel usually made by the electric furnace process in which chromium and nickel participate as alloying elements. The stainless steel of 18% chromium and 8% nickel are the better known of the chromium-nickel types.

Chromizing
A surface treatment at elevated temperature, generally carried out in pack, vapor, or salt bath, in which an alloy is formed by the inward diffusion of chromium into the base metal.

Cigarette Knife Steel
Hardened, tempered and bright polished, 1.25 Carbon content- Chromium .15. Accurate flatness necessary and a high hardness with Rockwell C 51 to 53. Usual sizes are 4 3/4 wide and 6 wide x .004 to .010.

Clad Metal
A composite metal containing two or three layers that have been bonded together. The bonding may have been accomplished by co-rolling, welding, heavy chemical deposition or heavy electroplating.

(2) A composite metal containing two or three layers that have been bonded together. The bonding may have been accomplished by corolling, welding, casting, heavy chemical deposition, or heavy electroplating.

Cladding
A process for covering one metal with another. Usually the surfaces of fairly thick slabs of two metals are brought carefully into contact and are then subjected to co-rolling so that a clad composition results. In some instances a thick electroplate may be deposited before rolling.

Cleavage
Fracture of a crystal by crack propagation across a crystallographic plane of low index.

Cleavage Fracture
Fracture of a grain, or most of the grains, in a polycrystalline metal by cleavage, resulting in bright reflecting facets.

Cleavage Plane
A characteristic crystallographic plane or set of planes in a crystal on which cleavage fracture occurs easily.

Cluster Mill
A rolling mill where each of the two working rolls of small diameter is supported by two or more back-up rolls.

Cobalt
Chemical symbol Co. Element No. 27 of the periodic system; atomic weight 58.94. A gray magnetic metal, of medium hardness; it resists corrosion like nickel, which it resembles closely; melting point 2696 (degrees) F.; specific gravity 8.9. It is used as the matrix metal in most cemented carbides and is occasionally electroplated instead of nickel, the sulfate being used as electrolyte. Its principal function as an alloy in tool steel; it contributes to red hardness by hardening ferrite.

Coil Breaks
Creases or ridges across a metal sheet transverse to the direction of coiling, occasionally occurring when the metal has been coiled hot and uncoiled cold.

Coil Set or Longitudinal Curl
A lengthwise curve or set found in coiled strip metals following its coil pattern. A departure from longitudinal flatness. Can be removed by roller or stretcher leveling from metals in the softer temper ranges.

Coil Weld
A joint between two lengths of metal within a coil - not always visible in the cold reduced product.

Coils
Coiled flat sheet or strip metal- usually in one continuous piece or length.

Coining
A process of impressing images or characters of the die and punch onto a plane metal surface.

Coke Plate (Hot Dipped Tin Plate)
Standard tin plate, with the lightest commercial tin coat, used for food containers, oil canning, etc. A higher grade is the best cokes, with special cokes representing the best of the coke tin variety. For high qualities and heavier coatings.

Cold Reduced Strip
Metal strip, produced from hot-rolled strip, by rolling on a cold reduction mill.

Cold Reduction
Reduction of metal size, usually by rolling or drawing particularly thickness, while the metal is maintained at room temperature or below the recrystallization temperature of the metal.

Cold Rolled Finish
Finish obtained by cold rolling plain pickled sheet or strip with a lubricant resulting in a relatively smooth appearance.

Cold Rolling
Rolling metal at a temperature below the softening point of the metal to create strain hardening (work-hardening). Same as cold reduction, except that the working method is limited to rolling. Cold rolling changes the mechanical properties of strip and produces certain useful combinations of hardness, strength, stiffness, ductility and other characteristics known as tempers, which see.

Cold Short
A condition of brittleness existing in some metals at temperatures below the recrystalization temperature.

Cold Shut
(1) A discontinuity that appears on the surface of cast metal as a result of two streams of liquid meeting and failing to unite. (2) A portion of the surface of a forging that is separated, in part, from the main body of metal by oxide.

Cold Work
Permanent strain produced by an external force in a metal below its recrystallization temperature.

Cold Working
Plastic deformation, such as rolling, hammering, drawing, etc., at a temperature sufficiently low to create strain-hardening (work-hardening). Commonly, the term refers to such deformation at normal temperatures.

Columbium
Chemical symbol Cb. Element No. 41 of the periodic system. Atomic weight 92.91. It is steel gray in color and brilliant luster. Specific gravity 8.57. Melting point at about 4380 (degrees) F. It is used mainly in the production of stabilized austenitic chromium-nickel steels, also to reduce the air-hardening characteristics in plain chromium steels of the corrosion resistant type. (Now known as Niobium (Nb), element No. 41 of the periodic system.)

Columnar Structure
A structure consisting of elongated grains whose tong axes are parallel.

(2) A coarse structure of parallel columns of grains, having the long axis perpendicular to the casting surface.

Commercial Bronze
A copper-zinc alloy (brass) containing 90% copper and 10% zinc; used for screws, wire, hardware, etc. Although termed commercial-bronze it contains no tin. It is somewhat stronger than copper and has equal or better ductility.

Commercial Quality Steel Sheet
Normally to a ladle analysis of carbon limit at 0.15 max. A Standard Quality Carbon Steel Sheet.

Compressive Strength
The maximum compressive stress that a material is capable of developing, based on original area of cross section. In the case of a material which fails in compression by a shattering fracture, the compressive strength has a very definite value. In the case of materials which do not fail in compression by a shattering fracture, the value obtained for compressive strength is an arbitrary value depending upon the degree of distortion that is regarded as indicating complete failure of the material.

Constitute
A phase, or combination of phases, that occurs in a characteristic configuration in a microstructure.

Constitutional Diagram
A graphical representation of the temperature and composition limits of phase fields in an alloy system as they actually exist under specific conditions of heating and cooling (synonymous with phase diagram). A constitutional diagram may be, or may approximate, and equilibrium diagram, or may represent metastable conditions or phases. Compare equilibrium diagram.

Continuous Casting
A casting technique in which the ingot is continuously solidified while it is being poured, and the length is not determined by mold dimensions.

Continuous Casting
A casting technique in which an ingot, billet, tube, or other shape is continuously solidified while it is being poured, so that its length is not determined by mold dimensions.

Continuous Furnace
Furnace, in which the material being heated moves steadily through the furnace.

Continuous Phase
In an alloy or portion of an alloy containing more than one phase, the phase that forms the background or matrix in which the other phase or phases are present as isolated volumes.

Continuous Pickling
Passing sheet or strip metal continuously through a series of pickling and washing tanks.

Continuous Strip Mill
A series of synchronized rolling mill stands in which coiled flat rolled metal entering the first pass (or stand) moves in a straight line and is continuously reduced in thickness (not width) at each subsequent pass. The finished strip is recoiled upon leaving the final or finishing pass.

Controlled Atmosphere Furnaces
A furnace used for bright annealing into which specially prepared gases are introduced for the purpose of maintaining a neutral atmosphere so that no oxidizing reaction between metal and atmosphere takes place.

Controlled Rolling
A hot rolling process in which the temperature of the steel is closely controlled, particularly during the final rolling passes, to produce a fine-grain microstructure.

Converter
A furnace in which air is blown through the molten bath of crude metal or matte for the purpose of oxidizing impurities.

Cooling Stresses
Stresses developed by uneven contraction or external constraint of metal during cooling; also those stresses resulting from localized plastic deformation during cooling, and retained.

Copper
Chemical symbol Cu) Element No. 29 of the periodic system, atomic weight 63.57. A characteristically reddish metal of bright luster, highly malleable and ductile and having high electrical and heat conductivity; melting point 1981 (degrees) F.; boiling point 4327 F.; specific gravity 8.94. Unibersally and extensively used in the arts in brasses, bronzes. Universally used in the pure state as sheet, tube, rod and wire and also as alloyed by other elements and an alloy with other metals.

Coring
A variation of composition between the center and surface of a unit of structure (such as a dendrite, a grain or a carbide particle) resulting from non-equilibrium growth over a range of temperature.

Corrosion
Gradual chemical or electrochemical attack on a metal by atmosphere, moisture or other agents.

(2) Deterioration of a metal by chemical or electrochemical reaction with its environment.

Corrosion Embrittlement
The severe loss of ductility of a metal resulting from corrosive attack, usually intergranular and often not visually apparent.

(2) The embrittlement caused in certain alloys by exposure to a corrosive environment. Such material is usually susceptible to the intergranular type of corrosion attack.

Corrosion Fatigue
Effect of the application of repeated or fluctuating stresses in a corrosive environment characterized by shorter life than would be encountered as a result of either their repeated or fluctuating stresses alone or the corrosive environment alone.

Corrugated
As a defect. Alternate ridges and furrows. A series of deep short waves.

Covered Electrode
A filler-metal electrode, used in arc welding, consisting of a metal core vire with a relatively thick covering which provides protection for the molten metal form the atmosphere, improves the properties of the weld metal and stabilizes the arc. The covering is usually mineral or metal powders mixed with cellulose or other binder.

Creep
Time-dependent strain occurring under stress.

(2) The flow or plastic deformation of metals held for long periods of time at stresses lower than the normal yield strength. The effect is particularly important if the temperature of stressing is above the recrystallization temperature of the metal.

(3) Time-dependent strain occurring under stress. The creep strain occurring at a diminishing rate is called primary creep; that occurring at a minimum and almost constant rate, secondary creep; that occurring at an accelerating rate, tertiary creep.

Creep Limit
(1) The maximum stress that will cause less than a specified quantity of creep in a given time. (2) The maximum nominal stress under which the creep strain rate decreases continuously with time under constant load and at constant temperature. Sometimes used synonymously with creep strength.

Creep Strength
(1) The constant nominal stress that will cause a specified quantity of creep in a given time at constant temperature. (2) The constant nominal stress that will cause a specified creep react at constant temperature.

Crevice Erosion
A type of concentration-cell corrosion; corrosion of a metal that is caused by the concentration of dissolved salts, metal ions, oxygen, or other gases, and such, in crevices or pockets remote from the principal fluid stream, with a resultant building up of differential cells that ultimately cause deep pitting.

Critical Cooling Rate
The limiting rate at which austenite must be cooled to ensure that a particular type of transformation product is formed.

(2) The minimum rate of continuous cooling just sufficient to prevent undesired transformations. For steel, the slowest rate at which it can be cooled form above the upper critical temperature to prevent the decomposition of austenite at any temperature above the Ms.

Critical Point
(1) The temperature or pressure at which a change in crystal structure, phase or physical properties occurs; same as transformation temperature. (2) In an equilibrium diagram, that specific combination of composition, temperature and pressure at which the phases of an inhomogeneous system are in equilibrium.

Critical Points
Temperatures at which internal changes or transformations take place within a metal either on a rising or falling temperature.

Critical Range
A temperature range in which an internal change takes place within a metal. Also termed transformation range.

Critical Strain
That strain which results in the formation of very large grains during recrystallization.

Critical Temperature
Synonymous with critical point if pressure is constant.

Crop
The defective ends of a rolled or forged product which are cut off and discarded.

Cross Rolling
The rolling of sheet so that the direction of rolling is changed about 90 (degrees) from the direction of the previous rolling.

Cross Direction (in rolled or drawn metal)
The direction parallel to the axes of the rolls during rolling. The direction at right angles to the direction of rolling or drawing.

Cross Rolling
Rolling at an angle to the long dimension of the metal; usually done to increase width.

Cross Rolling
A (hot) rolling process in which rolling reduction is carried out in a direction perpendicular to, as well as a direction parallel to, the length of the original slab.

Crown
A contour on a sheet or roll where the thickness or diameter increases from edge to center.

Crown or Heavy Center
Increased thickness in the center of metal sheet or strip as compared with thickness at the edge.

Crucible
A ceramic pot or receptacle made of graphite and clay, or clay or other refractory material, and used in the melting of metal. The term is sometimes applied to pots made of cast iron, cast steel or wrought steel.

Crucible Steel
High-carbon steel produced by melting blister steel in a covered crucible. Crucible steel was developed by Benjamin Huntsman in about 1750 and remained in use until the late 1940's.

Crystal
(1) A physically homogeneous solid in which the atoms. ions or molecules are arranged in a three-dimensional repetitive pattern. (2) A coherent piece of matter, all parts of which have the same anisotropic arrangement of atom; in metals, usually synonymous with grain and crystallite.

Crystalline
Composed of crystals.

Crystalline Fracture
A fracture of a polycrystalline metal characterized by a grainy appearance. Compare fibrous fracture.

Crystallization
The formation of crystals by the atoms assuming definite positions in a crystal lattice. This is what happens when a liquid metal solidifies. (Fatigue, the failure of metals under repeated stresses, is sometimes falsely attributed to crystallization.)

Cube-Centered
Metallography- (concerning space lattices) - Body-centered cubic. Refers to crystal structure.

Cup Fracture
A type of fracture in a tensile test specimen which looks like a cup having the exterior portion extended with the interior slightly depressed.

Cup Fracture (Cup-and-Cone Fracture)
Fracture, frequently seen in tensile test pieces of a ductile material, in which the surface of failure on one portion shows a central flat area of failure in tension, with an exterior extended rim of failure in shear.

Cutting Speed
The linear or peripheral speed of relative motion between the tool and work piece in the principal direction of cutting.

Cyaniding
Introducing carbon and nitrogen into a solid ferrous alloy by holding above Ac1 in contact with molten cyanide of suitable composition. The cyanided alloy is usually quench hardened.

(2) Surface hardening of an iron-base alloy article or portion of it by heating at a suitable temperature in contact with a cyanide salt, followed by quenching.