QUARTER HARD (No 3 TEMPER)
(A) In low carbon cold-rolled strip steel, a medium soft temper produced by a limited amount of cold rolling after annealing. (B) In brass2 mill terminology. Quarter-Hard is one B and S number hard or 10.95% reduction. (C) In stainless3 steel terminology tempers are based on minimum tensile, or yield strength. For Chromium-Nickel grades Quarter Hard Temper is 125,000 T.S., 75,000 Y.S. min.
QUENCHING5
In the heat treating of metals, the step of cooling metals rapidly in order to obtain desired properties; most commonly accomplished6 by immersing the metal in oil or water. In the case of most copper7 base alloys9, quenching has no effect other than to hasten cooling.
QUENCH4 HARDENING
(Steel) - A process of hardening a ferrous alloy8 of suitable composition by heating within or above the transformation10 range and cooling at a rate sufficient to increase the hardness substantially. The process usually involves the formation of martensite.
Metal Terminology R
RADIANT TUBE ANNEALING BOX
(See Annealing) - A box which is heated, inside, by means of tubes on which gas is burned; the hot tubes radiate their heat to the covered pile of metal, standing11 on the base of the box. Usually a protective atmosphere is maintained in the box to protect the metal from oxidation.
RADIOGRAPHY
A nondestructive method of internal examination in which metal objects are exposed to a beam of X-ray or gamma radiation. Differences in thickness, density12 or absorption, caused by internal defects or inclusions, are apparent in the shadow image either on a fluorescent13 screen or on photographic film placed behind the object.
RAGGED14 EDGES
Edges of sheet or strip which are torn, split, cracked, ragged or burred or otherwise disfigured.
RECIPROCAL LATTICE
(For a crystal) - A group of points arranged about a center in such a way that the line joining each point to the center is perpendicular15 to a family of planes in the crystal, and the length of this line is inversely16 proportional to their interplanar distance.
RECOVERY
The removal of residual17 stresses by localized plastic flow as the result of low-temperature annealing operations performed on cold worked metals without altering the grain structure or strength properties substantially.
RECRYSTALLIZATION
A process whereby a distorted grain structure of cold worked metals is replaced by a new, stress-free grain structure as a result of annealing above a specific minimum temperature for a specific time.
RED BRASS
85% Copper - A copper-zinc18 alloy containing approximately 15% zinc, used for plumbing19 pipe, hardware, condenser20 tubes. Because of its color, is used for vanity cases, coins, plaques21, badges, etc. It is somewhat stronger than commercial bronze and is hardened more rapidly by cold working.
RED SHORTNESS
Brittleness in steel when it is red hot.
REDUCTION OF AREA
The percent of cross-sectional area the metal will “Neck Down” prior to breaking in tension.
% R.A. = Original area - Area after Fracture x 100
REFINING TEMPERATURE
A temperature, usually just higher than the transformation range, employed in the heat treatment of steel to refine the structure - in particular, the grain size.
REFLECTOR SHEET
An alclad product containing on one side a surface layer of high-purity aluminum22 superimposed on a core or base alloy of commercial-purity aluminum or an aluminum-manganese alloy. The high-purity coating imparts good polishing characteristics and the core gives adequate strength and formability.
REFRACTORY24
A heat-resistant material, usually nonmetallic, which is used for furnace linings25 and such.
REFRACTORY ALLOY
A term applied26 to those alloys which due to hardness or abrasiveness27 present relative difficulty in maintaining close dimensional tolerances28.
REPHOSPHORIZING
(Steel) - A Ladle-chemical treatment consisting of the addition of phosphorus as a work hardening agent when temper rolling black plate or sheet steel resulting in greater hardness and stiffness and with a corresponding loss in ductility29.
NOTE - Black Plate in tempers T5 and T6 (R/B range 68/84) are temper rolled from Rephosphorized steel.
RESIDUAL STRESS
Macroscopic stresses that are set up within a metal as the result of non-uniform plastic deformation30. This deformation may be caused by cold working or by drastic gradients of temperature from quenching or welding.
RESIDUALS
“Incidental” or “tramp” elements not named in a specification31. These inclusions are usually due to contaminated scrap32.
RESILIENCE
The tendency of welding process in which the work pieces are heated by the passage of an electric current through the contact. Such processes include spot welding, seam or line welding and percussion33 welding. Flash and butt34 welding are sometimes considered as resistance welding processes.
RESISTANCE WELDING
A type of welding process in which the work pieces are heated by the passage of an electric current through the contact. Such processes include spot welding, seam or line welding and percussion welding. Flash and butt welding are sometimes considered as resistance welding processes.
RIBBON WOUND
A term applied to a common method of winding35 strip steel layer upon layer around an arbor36 or mandrel.
RIFFLES
Waviness at the edge of sheet or strip.
RIMMED37 STEEL
Low-carbon steel in which incomplete deoxidation permits the metal to remain liquid at the top of the ingot, resulting in the formation of a bottom and side rim23 of considerable thickness. The rim is of somewhat purer composition than the original metal poured. If the rimming38 action is stopped shortly after pouring of the ingot is completed, the metal is known as capped steel. Most steels below 0.15% carbon are rimmed steels. For the same carbon and manganese content rimmed steel is softer than killed steel.
RIPPLE
(Defect) - A slight transverse wave or shadow mark appearing at intervals39 along the piece.
ROCKWELL HARDNESS (TEST)
A standard method for measuring the hardness of metals. The hardness is expressed as a number related to the depth of residual penetration40 of a steel ball or diamond cone41 (“brale”) after a minor42 load of 10 kilograms has been applied to hold the penetrator in position. This residual penetration is automatically registered on a dial when the major load is removed from the penetrator. Various dial readings combined with different major loads, give “scales” designated by letters varying from “A” to “H”; the “B” and “C” scales are most commonly in use.
ROENTGEN RAYS
(See X-rays)
ROLL FORMING
An operation used in forming sheet. Strips of sheet are passed between rolls of definite settings that bend the sheet progressively into structural43 members of various contours, sometimes called “molded sections.”
ROLLED EDGES
Finished edges, the final contours of which are produced by side or edging rolls. The edge contours most commonly used are square corners, rounded corners and rounded edge.
ROLLED IN SCALE
A surface defect consisting of scale partially44 rolled into the surface of the sheet.
ROLLER LEVELING
Passing sheet or strip metal through a series of staggered small rolls so as to flatten45 the metal. This method is relatively46 ineffective in removing defects such as buckles47, wavy48 edges, corrugations, twists, etc., or from steel in the higher hardness ranges.
ROLLING
A term applied to the operation of shaping and reducing metal in thickness by passing it between rolls which compress, shape and lengthen49 it following the roll pattern.
ROLLING DIRECTION
(In rolled metal) - The direction, in the plane of the sheet, perpendicular to the axes of the rolls during rolling.
ROLLING MILLS
Equipment used for rolling down metal to a smaller size or to a given shape employing sets of rolls tie contours of which determine or fashion the product into numerous intermediate and final shapes, e.g., blooms, slabs50, rails, bars, rods, sections, plates, sheets and strip.
ROTARY51 SHEAR
(Slitting52 Machine) - A cutting machine with sharpened circular blades or disc-like cutters used for trimming edges and slitting sheet and foil. NOTE: Cutter discs are also employed in producing circles from flat sheets but with differently designed machines.
RULE DIE STEEL
A hardened and tempered medium high carbon spring steel strip sufficiently low hardness to take moderately sharp bends without fracture, intended for manufacture into rule dies for the purpose of cutting or stamping fabrics, paper, cardboard, plastics, and metal foil into desired shape