T

T/Cs
a treatment charge made by galvanisers and refiners for their services.

• WHAT
  Natural mineral containing less than 30% iron. It is the primary ore used in blast furnaces.
   
• WHY
  Domestic supplies of iron-rich ores (greater than 50% iron) were largely depleted in the 1940s, so integrated steel companies now process the lower-grade taconite to make it useful.

Tailored Blanks
A section of sheet or strip that is cut-to-length and trimmed to match specifications for the manufacturer's stamping design for a particular part. Because excess steel is cut away (to save shipping costs), all that remains for the stamper is to impart the three-dimensional shape with a die press (see Blanking).

Tandem Mill
A type of cold-rolling mill, the tandem mill imparts greater strength, a uniform and smoother surface, and reduced thickness to the steel sheet. Unlike the original single-stand mills, a tandem mill rolls steel through a series of rolls (generally three to five in a row) to achieve a desired thickness and surface quality.

Tantalum (Ta)
A by-product of tin processing, this refractory metal is used as a barrier to corrosion of chemical processing and carbide cutting tools, and still-growing use as electronic capacitors and filaments. Melts at 2415 degrees Fahrenheit.

Taper Section
A section made at an acute angle to a surface of interest, thereby achieving a geometrical magnification of depth. A sectioning angle 5(degrees) 43 achieves a depth magnification of 10: 1.

Tapping
Transferring molten metal from melting furnace to ladle.

Tarnish
Surface discoloration on a metal, usually from a thin film of oxide or sulfide.

Teeming
Pouring molten metal from a ladle into ingot molds. The term applies particularly to the specific operation of pouring either iron or steel into ingot molds.

Temper

• (1) In heat treatment, re-heating hardened steel or hardened steel or hardened cast iron to some temperature below the eutectoid temperature for the purpose of decreasing the hardness and increasing the toughness. The process also is sometimes applied to normalized steel.
   
• (2) In tool steels, temper is sometimes used, but unadvisedly, to denote the carbon content.
   
• (3) In nonferrous alloys and in some ferrous alloys (steels that cannot be hardened by heat treatment), the hardness and strength produced by mechanical or thermal treatment, or both, and characterized by a certain structure, mechanical properties, or reduction in area during cold working.

It is the state of or condition of a metal as to its hardness or toughness produced by either thermal treatment or heat treatment and quench or cold working or a combination of same in order to bring the metal to its specified consistency. Each branch of the metal producing industry has developed its own system of temper designates. In flat rolled products including sheet and strip steel, tin mill products, stainless strip, aluminum sheet and copper base alloy strip; they are shown as follows:

• COPPER BASED ALLOYS (Cold Rolled) - B S Gage Numbers.

NOTE - Hardness is indicated condition, Hardness varies with alloy changes.

Temper                                                                          Hardness

Annealed ......................................................................Commercially Soft

Quarter Hard ................................................................One Number Hard

Half Hard .....................................................................Two Numbers Hard

Hard Temper ................................................................Four Numbers Hard

Extra Hard ....................................................................Six Numbers Hard

Spring Temper ..............................................................Eight Numbers Hard

Extra Spring Temper .....................................................Ten Numbers Hard

• SHEET STEEL (Low Carbon Cold Rolled) - Temper Classifications.

Temper                                                                          Hardness

Full Hard . .................................................................... .069 and thinner B 90 min.

..................................................................................... .070 and thinner B 84 min.

Half Hard ..................................................................... Approx. R/B 70/85

Quarter Hard ............................................................... Approx. R/B 60/75

Soft Commercial Quality .............................................. Approx. R/B 66 max.

Drawing Quality ........................................................... Approx. R/B 55 max.

• STAINLESS STRIP STEEL (Cold Rolled Temper Classification) - Type 301.

NOTE - The various stainless strip tempers are based on specified minimum values for tensile strength or yield strength or both. However, because of custom, both distributors and customers alike rely on approximate Rockwell readings for temper classification. To illustrate:

Temper (Type 301)                                Rockwell                            Tensile Psi

Soft ................................................ Approx. B 75/85 ...................... 110,000 Min.

Quarter Hard .................................. Approx. C 25/30 ..................... 125,000 Min.

Half Hard ........................................ Approx. C 30/35 ..................... 150,000 Min.

Three Quarters Hard ....................... Approx. C 35/40 ..................... 175,000 Min.

Full Hard ......................................... Approx. C 40/45 ..................... 185,000 Min.

Extra Hard (Type 301) .................... Approx. C 45 min .................... 200,000 Min.

Type 430 Soft ................................. Approx. B 75/85 ...................... 75/85,000

• STRIP STEEL (Low Carbon Cold Rolled) - Temper Classifications.

Temper                                   Rockwell                                         Tensile

No. 1 Full Hard .................. .069 and thinner B 90 min. ..................... 80,000

........................................... .070 and thicker B 84 min. ..................... 80,000

No.2 Half hard ............................................. B 70/85 ....................... 64,000

No.3 Quarter Hard ...................................... B 60/75 ........................ 54,000

No.4 Skin Rolled ......................................... B 65 max. ..................... 48,000

No. 5 Dead Soft .......................................... B 55 max.

• TEMPERED SPRING STEELS (Strip) - Temper indication is to Rockwell Hardness only.

TIN MILL PRODUCTS (Steel) Temper Classifications - NOT STANDARDIZED. FOR INFORMATION ONLY. (Not to be confused with the Cold Rolled Strip Steel Temper Numbering System wherein No. 1 Temper indicates Full Hard, while in the TIN MILL Product Numbering System No. 1 Temper indicates a soft condition.) The following Rockwell ranges are approx. only.

Temper-Number                                  Rockwell - 30 T Scale.           Rockwell B Scale

No. 1 Temper ........................................ Aim at 46/52 ............................ Aim at 45/53

No. 2 Temper ........................................ Aim at 50/56 ............................ Aim at 51/59

No. 21/2 Temper ................................... Aim at 52/58 ............................ Aim at 53/62

No. 3 Temper ........................................ Aim at 54/60 ............................ Aim at 56/66

No.4 Temper ......................................... Aim at 58/64 ............................ Aim at 62/71

*No. 5 Temper ...................................... Aim at 62/68 ............................ Aim at 68/77

*No. 6 Temper ...................................... Aim at 62/73 ............................ Aim at 75/84

*NOTE: Tempers 5 and 6 are temper rolled from re-phosphorized steel in order to develop desired hardness and stiffness. The above temper classifications are used principally by producing mills and can manufacture but are not in general use in the sheet and strip industry.

Telescoping
Transverse slipping of successive layers of a coil so that the edge of the coil is conical rather than flat.

Temper Brittleness
Brittleness that results when certain steels are held within, or are cooled slowly through, a certain range of temperature below the transformation range. The brittleness is revealed by notched-bar impact tests at or below room temperature.

Temper Embrittlement
Brittleness that results when certain steels are held within, or are cooled slowly through, a specific range of temperatures below the transformation range. The brittleness is revealed by notched-bar impact tests at or below room temperature.

Temper Mill
A type of cold-rolling mill, usually with only one or two stands, that finishes cold-rolled, annealed sheet steel by improving the finish or texture to develop the required final mechanical properties. By changing the rolls of the temper mill, steel can be shipped with a shiny, dull or grooved surface.

Temper Rolling
Subjecting metal sheet or strip to a slight amount of cold rolling following annealing (usually 1/2 to 1 1/2%) The operation is performed to improve flatness, to minimize the formation of stretcher strains, and to obtain a specified hardness or temper.
Also termed Pinch Pass or Skin Rolled.

Tempered and Polished Spring Steel Strip
90/1.03 carbon range (Also known as clock spring steel.) This product, while similar to general description under heading of Tempered Spring Steel Strip, is manufactured and processed with great and extreme care exercised in each step of its production. Manufactured from carbon range of .90/1.03 with Rockwell range C 48/51. Clock spring quality has been ground and polished with edges dressed. It is usually supplied hard blue in color and has a wide range of uses, such as coiled and flat mechanical springs, ignition vibrator springs, springs for timing devices, springs for the electric and electronic fields, steel tapes, rules, etc.

Tempered Spring Steel Strip
Any medium or high carbon (excluding clock spring) strip steel of spring quality which has been hardened and tempered to meet specifications. Where specification calls for blue or straw color, same is accomplished by passing through heat prepared at proper temperature depending on color required. Blue is developed at approximately 600 (degrees) F.

Tempering
A process of re-heating quench-hardened or normalized steel to a temperature below the transformation range and then cooling at any rate desired. The primary purpose of tempering is to impart a degree of plasticity or toughness to the steel to alleviate the brittleness of its martensite.

Tensile Strength (Test)
(Also called Ultimate Strength) - Breaking strength of a material when subjected to a tensile (stretching) force. Usually measured by placing a standard test piece in the jaws of a tensile machine, gradually separating the jaws, and measuring the stretching force necessary to break the test piece. Tensile strength is commonly expressed as pounds (or tons) per square inch of original cross section.

Tension test
A test in which a machined or full-section specimen is subjected to a measured axial load sufficient to cause fracture. the usual information derived includes the elastic properties, ultimate tensile strength, and elongation and reduction area.

Ternary Alloy
An alloy that contains three principal elements.

Terne Plate
Sheet steel, coated with a lead-tin alloy. The percentage of tin is usually kept as low as possible because of its high cost; however, about 15% is normally necessary in order to obtain proper coating of the steel, since pure lead does not alloy with iron and some surface alloying is necessary for proper adhesion.
Terne principally is used in the manufacture of gasoline tanks, although it also can be found in chemical containers, oil filters and television chassis.

Test piece
Components welded together in accordance with a specified welding procedure, or a portion of a welded joint detached from a structure for test.

Test specimen
A portion detached for a test piece and prepared as (Test coupon)

Thermal Analysis
A method of studying transformations in metal by measuring the temperatures at which thermal arrests occur.

Thermal cutting
The parting or shaping of materials by the application of heat with or without a stream of cutting oxygen.

Thermocouple
A device for measuring temperatures by the use of two dissimilar metals in contact; the junction of these metals gives rise to a measurable electrical potential with changes in temperature.

Thermo-mechanical-controlled-processing (TMCP)
A term referring to special rolling practices that use controlled-rolling and/or accelerated cooling.

Thermal Treatment
Any operation involving the heating and cooling of a metal or alloy in the solid state to obtain the desired microstructure or mechanical properties.

Thickness Gage or Feeler Stock
A hardened and tempered, edged, ground, and polished thin section, high carbon strip steel. Usually 1/2 in width and in thicknesses from .001 to .050 manufactured to extremely close tolerances. It is used primarily for determining measurement of openings by tool and die makers, machinists, and automobile technicians. It is prepared in handy pocket size knife-like holders containing an assembly of various thicknesses. Also prepared in standard 12 lengths with rounded ends and in 10 ' and 25' coils. Universally used in the metal industry.

Three-Quarter Hard Temper
(A) In stainless steel strip tempers are based on a minimum tensile or yield strength. For Chromium-Nickel grades three-quarter hard temper is 175,000 T.S., 135,000 Y.S. min.
(B) In Brass mill terminology, this temper is three B&S numbers hard or 29.4% thickness reduction.

TIG - welding
Inert-gas welding using a non-consumable electrode (inert-gas tungsten-arc welding)

Tin (Sn)
(Chemical symbol Sn) Element No. 50 of the periodic system; atomic weight 118.70. Soft silvery white metal of high malleability and ductility, but low tensile strength; melting point 449 (degrees) F., boiling point 4384 (degrees) F., yielding the longest molten-state range for any common metal; specific gravity 7.28. Principal use as a coating on steel in tin plate; also as a constituent in alloys.

Tin Mill
Continuous tin-plating facility to produce tin mill steel sheet to be used in food and beverage cans and other containers.

Tin Plate
Thin sheet steel with a very thin coating of metallic tin. Tin plate is used primarily in can making.

Tin Plate Base Box
A Tin Plate Base Box is measured in terms of pounds per Base Box (112 sheets 14 x 20) a unit peculiar to the tin industry. This corresponds to it's area of sheet totaling to 31.360 square inches of any gage and is applied to tin plate weighing from 55 to 275 pounds per base box. To convert to decimal thickness multiply weight per base box by .00011.

Tin/Chrome Plating
A plating process whereby the molecules from the positively charged tin or chromium anode attach to the negatively charged sheet steel. The thickness of the coating is readily controlled through regulation of the voltage and speed of the sheet through the plating area.

Tin-Free Steel
Chromium-coated steel. Because it is used in food cans just like tin plate, it ironically is classified as a tin mill product. Tin-free steel is easier to recycle because tin will contaminate scrap steel in even small concentrations.

Tinning
Coating with tin, commonly either by immersion into molten tin or by electro-deposition; also by spraying.

Titanium (Ti)
Chemical symbol Ti. Element No. 22 of the periodic system; atomic weight 47.90; melting point about 3270 (degrees) F.; boiling point over 5430 (degrees) F.; specific gravity 4.5. Bright white metal, very malleable and ductile when exceedingly pure. Its principal functions as an alloy in the making of steel.

(1) Fixes carbon in inert particles

• (a) Reduces martensitic hardness and hardenability in medium chromium steels.
• (b) prevents formation of austenite in high-chromium steels.
• (c) prevents localized depletion of chromium in stainless steel during long heating. Now finding application in its own right because of its high strength and good corrosion resistance.

Titanium-based Superalloys
Lightweight, corrosive-resistant alloys suitable for high temperatures. These alloys are very practical for airplane parts. Titanium alloys can be blended with aluminium, iron, vanadium, silicon, cobalt, tantalum, zirconium, and manganese.
 

Toe
The boundary between a weld face and the parent metal or between weld faces.

Tolerances
A customer's specifications can refer to dimensions or to the chemical properties of steel ordered. The tolerance measures the allowable difference in product specifications between what a customer orders and what the steel company delivers. There is no standard tolerance because each customer maintains its own variance objective. Tolerances are given as the specification, plus or minus an error factor; the smaller the range, the higher the cost.

Tolerance Limit
The permissible deviation from the desired value.

Toll Processing
The act of processing steel for a fee ("toll"). Owners of the steel sheet may not possess the facilities to perform needed operations on the material (or may not have the open capacity). Therefore, another steel mill or service center will slit, roll, coat, anneal, or plate the metal for a fee.

Ton
Unit of measure for steel scrap and iron ore.

• Gross Ton 2,240 pounds.
• Long (Net) Ton 2,240 pounds.
• Short (Net) Ton 2,000 pounds.
  Normal unit of statistical raw material input and steel output in the United States.
• Metric Ton 1,000 kilograms. 2,204.6 pounds or 1.102 short tons.

Tong Hold
The portion of a forging billet, usually on one end, that is gripped by the operator's tongs. It is removed from the part at the end of the forging operation. Common to drop-hammer and press-type forging.

Tongue-bend test specimen
A potion so cut in two straight lengths of pipe joined by a butt weld as to produce a tongue containing a portion of the weld. The cuts are made so that the tongue is parallel to the axis of the pipes and the weld is tested by bending the tongue

Tool Steels
Steel with a higher carbon and alloy content. Used to make tools for cutting, forming or otherwise shaping a material into a part or component for a definite use.

Torsion
A twisting action resulting in shear stresses and strains.

Touch welding
Metal-arc welding using a covered electrode, the covering of which is kept in contact with the parent metal during welding.

Toughness
An indication of a steel's capacity to absorb energy, particularly in the presence of a notch or a crack.

Trace
Extremely small quantity of an element, usually too small to determine quantitatively

Trade Case
A type of lawsuit filed by United States companies against their foreign counterparts in response to imports at prices lower than those in the U.S. market. Sanctions can be imposed by the International Trade Commission and the Commerce Department on foreign producers involved in dumping and government subsidization, if domestic manufacturers can prove material damage to their results.

Transformation
A constitutional change in a solid metal, e.g., the change from gamma to alpha iron, or the formation of pearlite from austenite.

Transformation Ranges (Transformation Temperature Ranges)
Those ranges of temperature within which austenite forms during heating and transforms during cooling. The two ranges are distinct, sometimes overlapping but never coinciding. The limiting temperatures of the ranges depend on the composition of the alloy and on the rate of change of temperature, particularly during cooling.

Transformation Temperature
The temperature at which a change in phase occurs. The term is sometimes used to denote the limiting temperature of a transformation range. The following symbols are used for iron and steels: . Ac(cm) In hypereutectoid steel, the temperature at which the solution of cementite in austenite is completed during heating. . Ac1 The temperature at which austenite begins to form during heating. . Ac3 The temperature at which transformation of ferrite to austenite is completed during heating. . Ac4 The temperature at which austenite transforms to delta ferrite during heating. . Ae(cm) Ae1 Ae3 Ae4 The temperatures of phase changes at equilibrium. . Ar(cm) In hypereutectoid steel, the temperature at which precipitation of cementite starts during cooling. . Ar1 The temperature at which transformation of austenite to ferrite or to ferrite plus cementite is completed during cooling. . Ar3 The temperature at which austenite begins to transform to ferrite during cooling. . Ar4 The temperature at which delta ferrite transforms to austenite during cooling. . M(s) (or Ar) The temperature at which transformation of austenite to martensite starts during cooling. . M(f) The temperature at which martensite formation finishes during cooling. . NOTE: All these changes except the formation of martensite occur at lower temperatures during cooling than during heating, and depend on the rate of change of temperature.

Transition Temperature
(1) An arbitrarily defined temperature within the temperature range in which metal fracture characteristics determined usually by notched tests are changing rapidly such as from primarily fibrous (shear) to primarily crystalline (cleavage) fracture. Commonly used definitions are transition temperature for 50% cleavage fracture, 10-ft-lb transition temperature, and transition temperature for half maximum energy.
(2) Sometimes also used to denote the arbitrarily defined temperature in a range in which the ductility changes rapidly with temperature.

Transition Temperature (ductile-brittle transition temperature)
An arbitrarily defined temperature that lies within the temperature range in which metal fracture characteristics (as usually determined by tests of notched specimens) change rapidly, such as from primarily fibrous (shear) to primarily cleavage.

Transverse
Literally, 'across', usually signifying a direction or plane perpendicular to the direction of working.

Troosite
A previously irresolvable rapidly etching fine aggregate of carbide and ferrite produced either by tempering martensite at low temperature or by quenching a steel at a rate slower than the critical cooling rate. Preferred terminology for the first product is tempered martensite; for the latter, fine pearlite.

Trowel Steel
Hardened and tempered spring steel. .90 to 1.05 carbon content. Ordinary tolerances, but rolled extra flat -- Rockwell C 50. Used in the manufacture of plastering trowels.

Truss Spring Steel
Supplied cold rolled and bright annealed. Carbon content about .70 -- Manganese .74. Must be formed very severely and must be as free as possible from decarburization.

Tubing
When referring to OCTG, tubing is a separate pipe used within the casing to conduct the oil or gas to the surface. Depending on conditions and well life, tubing may have to be replaced during the operational life of a well.

Tukon Hardness (Test)
A method for determining micro-hardness by using a Knoop diamond indenter or Vickers square-base pyramid indenter.

Tumbling
Cleaning articles by rotating them in a cylinder with cleaning materials.

Tundish
The shallow refractory-lined basin on top of the continuous caster. It receives the liquid steel from the ladle, prior to the cast, allowing the operator to precisely regulate the flow of metal into the mold.

Tungsten (W)
(Chemical symbol W) Element No. 74 of the periodic system; atomic weight 183.92. Gray metal of high tensile strength, ductile and malleable when specially handled. It is immune to atmospheric influences and most acids, but not to strong alkalis. The metal is used as filament and in thin sheet form in incandescent bulbs and radio tubes. (1) Forms hard abrasion -- resistant particles in tool steels. (2) Promotes hardness and strength at elevated temperatures.

Tungsten Carbide
Compound of tungsten and carbon, of composition varying between WC and W2C; imbedded in matrix of soft metal, such as cobalt, extensively used for Sintered Carbide Tools.

Tungsten inclusion
An inclusion of tungsten from the electrode in TIG-welding.

Tunnel Furnace
Type of furnace whereby stock to be heated is placed upon cars which are then pushed or pulled slowly through the furnace.

Twist
A winding departure from flatness.

Two-stage regulator
A gas regulator in which the gas pressure is reduced to the working pressure in two stages.

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