Гричин С.В., Ульянова О.В. - Английский язык для инженеров сварочного производства, страница 27

The penetrator may be either a steel ball or adiamond spherocone.ROOTSee ROOT OF JOINT and ROOT OF WELD.ROOT CRACKA crack in the weld or base metal which occurs at the root of a weld.ROOT EDGEThe edge of a part to be welded which is adjacent to the root.ROOT FACEThe portion of the prepared edge of a member to be joined by a grooveweld which is not beveled or grooved.ROOT OF JOINTThat portion of a joint to be welded where the members approachclosest to each other. In cross section, the root of a joint may be apoint, a line, or an area.ROOT OF WELDThe points, as shown in cross section, at which the bottom of the weldintersects the base metal surfaces.ROOT OPENINGThe separation between the members to be joined at the root of thejoint.ROOT PENETRATIONThe depth a groove weld extends into the root of a joint measured onthe centerline of the root cross section.SCARFThe chamfered surface of a joint.SCARFINGA process for removing defects and checks which develop in therolling of steel billets by the use of a low velocity oxygen deseamingtorch.145SEAL WELDA weld used primarily to obtain tightness and to prevent leakage.SEAM WELDINGWelding a lengthwise seam in sheet metal either by abutting oroverlapping joints.SELECTIVE BLOCK SEQUENCEA block sequence in which successive blocks are completed in acertain order selected to create a predetermined stress pattern.SERIES WELDINGA resistance welding process in which two or more welds are madesimultaneously by a single welding transformer with the total currentpassing through each weld.SHEET SEPARATIONIn spot, seam, and projection welding, the gap surrounding the weldbetween faying surfaces, after the joint has been welded.SHIELDED WELDINGAn arc welding process in which protection from the atmosphere isobtained through use of a flux, decomposition of the electrodecovering, or an inert gas.SHOULDERSee ROOT FACE.SHRINKAGE STRESSSee RESIDUAL STRESS.SINGLE IMPULSE WELDINGThe making of spot, projection, and upset welds by a single impulse ofcurrent.

When alternating current is used, an impulse may consist of afraction of a cycle or a number of cycles.SIZE OF WELDa. Groove weld. The joint penetration (depth of chamfering plus theroot penetration when specified).b. Equal leg fillet welds. The leg length of the largest isosceles righttriangle which can be inscribed within the fillet weld cross section.c. Unequal leg fillet welds. The leg length of the largest right trianglewhich can be inscribed within the fillet weld cross section.d. Flange weld.

The weld metal thickness measured at the root of theweld.SKIP SEQUENCESee WANDERING SEQUENCE.SLAG INCLUSIONNon-metallic solid material entrapped in the weld metal or between theweld metal and the base metal.146SLOT WELDA weld made in an elongated hole in one member of a lap or tee jointjoining that member to that portion of the surface of the other memberwhich is exposed through the hole. The hole may be open at one endand may be partially or completely filled with weld metal.

(A filletwelded slot should not be construed as conforming to this definition.)SLUGGINGAdding a separate piece or pieces of material in a joint before or duringwelding with a resultant welded joint that does not comply with designdrawing or specification requirements.SOLDERINGA group of welding processes which produce coalescence of materialsby heating them to suitable temperature and by using a filler metalhaving a liquidus not exceeding 450 °C (842 °F) and below the solidusof the base materials. The filler metal is distributed between the closelyfitted surfaces of the joint by capillary action.SOLIDUSThe highest temperature at which a metal or alloy is completely solid.SPACER STRIPA metal strip or bar inserted in the root of a joint prepared for a grooveweld to serve as a backing and to maintain the root opening duringwelding.SPALLSmall chips or fragments which are sometimes given off by electrodesduring the welding operation.

This problem is especially common withheavy coated electrodes.SPATTERThe metal particles expelled during arc and gas welding which do notform a part of the weld.SPOT WELDINGA resistance welding process in which fusion is produced by the heatobtained from the resistance to the flow of electric current through theworkpieces held together under pressure by electrodes. The size andshape of the individually formed welds are limited by the size andcontour of the electrodes.SPRAY TRANSFERA type of metal transfer in which molten filler metal is propelledaxially across the arc in small droplets.147STAGGERED INTERMITTENT FILLET WELDTwo lines of intermittent welding on a joint, such as a tee joint,wherein the fillet increments in one line are staggered with respect tothose in the other line.STORED ENERGY WELDINGThe making of a weld with electrical energy accumulatedelectrostatically, electromagnetically, or electrochemically at arelatively low rate and made available at the required welding rate.STRAIGHT POLARITYThe arrangement of direct current arc welding leads in which the workis the positive pole and the electrode is the negative pole of thewelding arc.STRESS RELIEVINGA process of reducing internal residual stresses in a metal object byheating to a suitable temperature and holding for a proper time at thattemperature.

This treatment may he applied to relieve stresses inducedby casting, quenching, normalizing, machining, cold working, orwelding.STRING BEAD WELDINGA method of metal arc welding on pieces 3/4 in. (19 mm) thick orheavier in which the weld metal is deposited in layers composed ofstrings of beads applied directly to the face of the bevel.STUD WELDINGAn arc welding process in which fusion is produced by heating with anelectric arc drawn between a metal stud, or similar part, and the otherworkpiece, until the surfaces to be joined are properly heated. They arebrought together under pressure.SUBMERGED ARC WELDINGAn arc welding process in which fusion is produced by heating with anelectric arc or arcs between a bare metal electrode or electrodes and thework.

The welding is shield by a blanket of granular, fusible materialon the work. Pressure is not used. Filler metal is obtained from theelectrode, and sometimes from a supplementary welding rod.SURFACINGThe deposition of filler metal on a metal surface to obtain desiredproperties or dimensions.TACK WELDA weld made to hold parts of a weldment in proper alignment until thefinal welds are made.148TEE JOINTA joint between two members located approximately at right angles toeach other in the form of a T.TEMPER COLORSThe colors which appear on the surface of steel heated at lowtemperature in an oxidizing atmosphere.TEMPERINGReheating hardened steel to some temperature below the lower criticaltemperature, followed by a desired rate of cooling. The object oftempering a steel that has been hardened by quenching is to releasestresses set up, to restore some of its ductility, and to developtoughness through the regulation or readjustment of the embrittledstructural constituents of the metal.

The temperature conditions fortempering may be selected for a given composition of steel to obtainalmost any desired combination of properties.TENSILE STRENGTHThe maximum load per unit of original cross-sectional area sustainedby a material during the tension test.TENSION TESTA test in which a specimen is broken by applying an increasing load tothe two ends. During the test, the elastic properties and the ultimatetensile strength of the material are determined.

After rupture, thebroken specimen may be measured for elongation and reduction ofarea.THERMIT CRUCIBLEThe vessel in which the thermit reaction takes place.THERMIT MIXTUREA mixture of metal oxide and finely divided aluminum with theaddition of alloying metals as required.THERMIT MOLDA mold formed around the parts to be welded to receive the moltenmetal.THERMIT REACTIONThe chemical reaction between metal oxide and aluminum whichproduces superheated molten metal and aluminum oxide slag.THERMIT WELDINGA group of welding processes in which fusion is produced by heatingwith superheated liquid metal and slag resulting from a chemicalreaction between a metal oxide and aluminum, with or without theapplication of pressure.

Filler metal, when used, is obtained from theliquid metal.149THROAT DEPTHIn a resistance welding machine, the distance from the centerline of theelectrodes or platens to the nearest point of interference for flatwork orsheets. In a seam welding machine with a universal head, the throatdepth is measured with the machine arranged for transverse welding.THROAT OF FILLET WELDa. Theoretical. The distance from the beginning of the root of the jointperpendicular to the hypotenuse of the largest right triangle that can beinscribed within the fillet-weld cross section.b.