A defect in metal produced by gas bubbles either on the surface or formed beneath the surface while the metal is hot or plastic. Very fine blisters are called "pin-head" or "pepper" blisters.
A vertical shaft type smelting furnace in which an air blast is used, usually hot, for producing pig iron. The furnace is continuous in operation using iron ore, coke, and limestone as raw materials which are charged at the top while the molten iron and slag are collected at the bottom and are tapped out at intervals.
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) From sheet bar on single stand sheet mills or sheer 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
(Scaleless Blue.) A flat cold rolled usually .70/60 medium high carbon spring steel strip, blue-black in color, which has been quenched in oil and drawn to desired hardness. While it looks and acts much like blue tempered spring steel and carries a Rockwell hardness of C 44/47, it has not been polished and is lower in carbon content.. Used for less exacting requirements than clock spring steel, such as snaps, lock springs, hold down springs, trap springs, etc. It will take a more severe bend before fracture than will clock spring, but it does not have the same degree of
A process of box annealing or pot annealing ferrous ?alloy sheet, strip or wire after hot working and pickling. See box annealing.
An alloy containing two elements, apart from minor ?impurities, as brass containing the two elements copper and zinc.
A steel making process in which air is blown through ?the molten iron so that the impurities are thus removed by oxidation.
An alloy of copper and 2-3% beryllium with optionally fractional percentages of nickel or cobalt. Alloys of this series show remarkable age-hardening properties and an ultimate hardness of about 400 Brinell (Rockwell C43). Because of such hardness and good electrical conductivity, beryllium-copper is used in electrical switches, springs, etc.
Various tests used to determine the toughness and ductility of flat rolled metal sheet, strip or plate, in which the material is bent around its axis 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 used then line the jaws with some soft metal or brass, so as to permit a free flow of the metal in the sample being tested.
The only commercial ore of aluminum, corresponding essentially to the formula Al2O3xH2O.
Is immersion in a liquid bath (such as molten lead or fused salts) held at an assigned temperature-when a lead bath is used, the process is known as lead annealing.
A steel making process either Bessemer, open hearth or electric, in which the furnace is lined with a basic refractory. A slag, rich in lime, being formed and phosphorous removed.
A steel making process wherein oxygen of the highest purity is blown onto the surface of a bath of molten iron contained in a basic lined and ladle shaped vessel. The melting cycle duration is extremely short with quality comparable to Open Hearth Steel.
Surface of metal, under the oxide-scale layer, resulting from heating in an oxidizing environment. In the case of steel, such bark always suffers from decarburization.
Appearance of a metal, under a microscope or viewed by the naked eye, on fractured or smoothed surfaces, with or without etching, showing parallel bands in the direction of rolling or working.
A hardened tempered bright published high carbon cold rolled spring steel strip produced especially for use in the manufacture of band saws for sawing wood, non ferrous metals, and plastics. Usually carries some nickel and with a Rockwell value of approximately C40/45.
A slender, needle-like (acicular) microstructure appearing in spring steel strip characterized by toughness and greater ductility than tempered Martensite. Bainite is a decomposition product of Austenite (see Austenite) best developed at interrupted holding temperatures below those forming fine pearlite and above those giving Martensite.
Steel which, because of the presence of alloying elements, such as manganese, nickel, chromium, etc., shows stability of Austenite at normal temperatures.
Phase in certain steels, characterized as a solid solution, usually off carbon or iron carbide, in the gamma form of iron. Such steels are known as "austenitic," Austenite is stable only above 1333 ?F. in a plain carbon steel, but the presence of certain alloying elements, such as nickel and manganese, stabilizes the austenitic form, even at normal temperatures.
A trade name for a patented heat treating process that consists in quenching a ferrous alloy from a temperature above the transformation ranges, in a medium having a rate of beat abstraction sufficiently high to prevent the formation of high-temperature transformation products and in maintaining the alloy, until transformation is complete, at a temperature below that of pearlite formation and above that of martensite formation.
An aging treatment above room temperature. See precipitation heat treatment and compare with natural aging.
(Aluminum Anodic Oxide Coating) - A process of coating aluminum by anodic treatment resulting in a thin film of aluminum oxide of extreme hardness. A wide variety of dye colored coatings are possible by impregnation in process.
A heating and cooling operation implying usually a relatively slow cooling. Annealing is a comprehensive term. The process of such a heat treatment may be: to remove stresses; to induce softness: to alter ductility; toughness; electrical magnetic, or other physical properties; to refine the crystalline structure; to remove gases: to produce a definite micro-structure. In annealing, the temperature of the operation and the rate of cooling depend upon the material being heat treated and the purpose of the treatment.
A steel where aluminum has been used as a deoxidizing agent. (See Killed Steel.]
(Chemical symbol Al] Element No. 13 of the periodic system; Atomic weight 26.97; silvery white metal of valence 3: melting point 1220°F.; boiling point approximately 4118°F.; ductile and malleable; stable against normal atmospheric corrosion, but attacked by both acids and alkalis. Aluminum is used extensively in articles requiring lightness, corrosion resistance, electrical conductivity, etc. Its principal functions as an alloy in steel making: [1] Deoxidizes efficiently (See Aluminum Killed) (2) Restricts grain growth (by forming dispersed oxides or nitrides) (3) Alloying element in nitriding steel (see).
The polymorphic form of iron, stable below 1670°F. has a body centered cubic lattice, and is magnetic up to 1410°F.
A copper-tin alloy consisting of the alpha solid solution of tin in copper. Commercial forms contain 4 or 5% of tin. This alloy is used in coinage, springs, turbine, blades, etc.
A copper-zinc alloy containing up to 38% of zinc. Used mainly for cold working.
Steel containing substantial quantities of elements other than carbon and the commonly-accepted limited amounts of manganese, sulfur, silicon, and phosphorous. Addition of such alloying elements is usually for the purpose of increased hardness, strength or chemical resistance. The metals most commonly used for forming alloy steels are: nickel, chromium, silicon, manganese, tungsten, molybdenum and vanadium. "Low Alloy" steels are usually considered to be those containing a total of less than 5% of such added constituents.
(Met.) Metal prepared by adding other metals or non-metals to a basic metal to secure desirable properties.
The common name for a type of clad wrought aluminum products, such as sheet and wire, with coatings of high-purity aluminum or an aluminum alloy different from the core alloy in composition. The coatings are anodic to the core so they protect exposed areas on the core electrolytically during exposure to corrosive environments,
Steels of the American Iron and Steel Institute. Common and alloy steels have been numbered in a system essentially the same as the SAE. The AISI system is more elaborate than the SAE in that all numbers are preceded by letters: "A" represents basic open-hearth alloy steel, "B" acid Bessemer carbon steel, "C" basic open-hearth carbon steel, "CB" either acid Bessemer or basic open-hearth carbon steel, "E" electric furnace alloy steel.
Alloy steel which may be hardened by cooling in air from a temperature above the transformation range. Such steels attain their martenstic structure without going through the quenching process. Additions of chromium, nickel, molybdenum and manganese are effective toward this end.
Cooling of the heated metal, intermediate in rapidity between slow furnace cooling and quenching, in which the metal is permitted to stand in the open air.
Spontaneous change in the physical properties of some metals, which occurs on standing, at atmospheric temperatures after final cold working or after a final heat treatment. Frequently synonymous with the term "Age-Hardening."
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.
The term has no reference to the acidity of the steel. (See acid process.)
A process of making steel, either Bessemer, open-hearth or electric, in which the furnace is lined with a siliceous refractory and for which low phosphorous pig iron is required as this element is not removed.
Brittleness resulting from pickling steel in acid; hydrogen, formed by the interaction between iron and acid, is partially absorbed by the metal, causing acid brittleness.
Abbreviation for American Society For Testing Material. An organization for issuing standard specifications on materials, including metals and alloys.
Hardened, tempered polished and blued or yellow flat steel with dressed edges. Carbon content about 1.00. Material has to possess good flatness, uniform hardness and high elasticity.