Jeffersons welding encyclopedia pdf free download

Not in Library. Libraries near you: WorldCat. Jefferson's welding encyclopedia First published in Subjects Dictionaries , Welding.

Edition Notes "Originally published as the Welding Encyclopedia. Other Titles Welding encyclopedia. The Physical Object Pagination x, p. Community Reviews 0 Feedback? Lists containing this Book. Loading Related Books. February 6, August 18, Edited by IdentifierBot. April 16, At another location, filler is mixed to correct proportions in hoppers, weighed, and mixed with water in agitators. Before each new batch of filler is used, a sample containing one cubic foot is weighed and examined to ensure correct mixture.

Cylinders are then filled automatically and weighed again. Factoring in the weight and volume of the cylinder confirms that it is accurately filled to specification. The cylinders are then oven-baked at C F to. Cylinders are checked after each procedure during the manufacturing process. Those not meeting the rigid requirements of federal law and company rules are rejected regardless of the stage of manufacture. For example, a number of cylinders are selected from each completed lot, charged with acetylene, and tested to ensure proper discharge.

If the cylinders do not meet specifications, the entire lot is rejected. Basic Tests. Baking time ranges from 40 to hours, depending on cylinder size. After baking, another weight check is made to determine if any water remains.

Fuse plugs and valves are installed, and cylinders are shot-blasted and painted. Fuse plugs are small steel machine bolts with holes filled with a lowmelting alloy designed to release gas in case of fire, and to lessen the acetylene pressure to reduce the possibility of an explosion. Finally, strength proof tests at kPa psi are run. Pressure is then reduced to kPa psi , and the cylinders are immersed in water to check for leaks. Drawn to a vacuum, they are charged with acetone and weighed again to determine if they are fully charged.

A bonfire test is designed to check cylinder performance under conditions similar to a fire in a building. A fully charged cylinder is placed horizontally on racks, and specified sizes and amounts of wood strips are ignited around it. The cylinder passes the test if there is no appreciable shell bulge, no penetration of filler by decomposition, and no breakup of the filler. The flashback test simulates torch flashback entering the cylinder, assumed to be at full pressure when the operator closes the valve immediately afterward.

If the flash is immediately quenched in the cylinder with only a minimum of decomposition and without release of fusible plugs, the cylinder passes the test. A hot spot test simulates negligent impinging of a torch flame against the cylinder. If filler decomposition is limited to the area closely adjacent to the resulting cavity, performance is satisfactory.

The bump test determines the fillers resistance to mechanical shock received during normal service. The cylinder is mounted on a foundry mold-bumper and subjected to minimum bumping cycles. At the conclusion of the test, satisfactory performance is indicated when there is no attrition, sagging, or cracking of the filler. At ambient conditions, increased pressure and decreased temperature can liquefy acetylene.

At extremely low temperatures, acetylene can solidify. The danger at the point of liquefaction or solidification and the major reason why acetylene cannot be distributed in this form is that the necessarily high pressures create a very unstable product. At the slightest provocation, compressed acetylene will dissociate into its chemical components, carbon and hydrogen.

This dissociation is accompanied by drastic increases in both temperature and pressure, and results in an explosion. The acetylene distributor, as well as the user, must observe important precautions: 1 Slings, hooks or magnets cannot be used to move cylinders. Cylinders of acetylene must be kept in an upright position. Cylinders cannot be dragged, and can never be used or stored in a horizontal position.

The supplier should be notified immediately. Acetylene will react with the copper to form copper acetylide, an unstable compound which can explode spontaneously. The intense white, feathery-edged portion adjacent to the cone of a carburizing oxyacetyleneflame.

See also Figure A- 1. In the United States, common practice has established a preference for the carbide-to-water machines, and they are almost universally used. There is another type of generator using calcium carbide molded into cakes, in which the water drops into the calcium carbide. This type of generator, while common in Europe, is almost unknown in the United States.

Insurance Regulations. The Underwriters Laboratories is an organization maintained by the insurance companies of the United States which provides for the inspection and testing of all types of equipment which may be considered a fire or accident hazard, including welding and cutting equipment and acetylene generators. There are estab-. Another insurance authority which publishes rules for acetylene generators is the Factory Mutual Engineering Organization, Norwood, Mass.

Brittleness induced in steel, especially wire or sheet, by pickling in dilute acid for the purpose of removing scale. This brittleness is commonly attributed to the absorption of hydrogen. A solder wire or bar containing acidflux as a core. A flux from which the amount of elements deposited in the weld metal is dependent on the welding conditions, primarily on the arc voltage. The shortest distance between the weld root and the face of a fillet weld. See Appendix 11, Figure A, 3.

A device for connecting two parts i. An adapter is sometimes used to connect a regulator to a tank which has a valve threaded differently from the inlet connection of the regulator.

This practice is not recommended. Pertaining to process control that automatically determines changes in process conditions and directs the equipment to take appropriate action.

Welding with a process control system that automatically determines changes in welding conditions and directs the equipment to take appropriate action.

Variations of this term are adaptive control brazing, adaptive control soldering, adaptive control thermal cutting, and adaptive control thermal spraying. Adaptive feedback control systems are automatic welding systems which make corrections to welding variables based on information gathered during welding.

The objective is to maintain weld quality at a constant level in the presence of changing welding conditions. Automatic adjustment of individual weld variables, such as arc current or arc length, is made by monitoring a weld characteristic, such as pool width. Other feedback control systems are available to provide electrode guidance and constant joint fill. A term sometimes used to describe the metal added to the base metal during arc, gas, or thermite welding.

Adhesive bonding is a materials joining process in which a nonmetallic adhesive material is placed between the faying surfaces of the parts or bodies, called adherends. The adhesive then solidifies or hardens by physical or chemical property changes to produce a bonded joint with useful strength between the adherends.

Adhesive is a general term that includes such materials as cement, glue, mucilage, and paste. Although natural organic and inorganic adhesives are available, synthetic organic polymers are usually used to join metal assemblies.

Various descriptive adjectives are applied to the term adhesive to indicate certain characteristics, as follows: 1 Physical form: liquid adhesive, tape adhesive 2 Chemical type: silicate adhesive, epoxy adhesive, phenolic adhesive 3 Materials bonded: paper adhesive, metal-plastic adhesive, can labeling adhesive 4 Application method: hot-setting adhesive, sprayable adhesive.

Although adhesive bonding is used to join many nonmetallic materials, the following paragraphs refer only to the bonding of metals to themselves or to nonmetallic structural materials.

Adhesive bonding is similar to soldering and brazing of metals in some respects, but a metallurgical bond does not take place. The surfaces being joined are not melted, although they may be heated. An adhesive in the form of a liquid, paste, or tacky solid is placed between the faying surfaces of the joint. After the faying surfaces are mated with the adhesive in between, heat or pressure, or both, are applied to accomplish the bond. An adhesive system must have the following characteristics: 1 At the time the bond is formed, the adhesive must become fluid so that it wets and comes into close contact with the surface of the metal adherends.

Otherwise, undesirable internal stresses may develop in the joint. A variety of adhesives can be used. Thermoplastic adhesives develop a bond through the evaporation of a solvent or the application of heat. The pressure-sensitive adhesives produce a bond when pressure is applied to the joint.

Other adhesives, usually used for metals, react chemically with curing agents or catalysts. Some epoxy-based adhesives can produce joint strengths up to 70 MPa 10 psi when cured at C F for a few hours under pressures of about kPa psi. The types of polymeric adhesives used to bond metal are listed in Table A- 1. Adhesive bonding is also capable of joining dissimilar materials, for example, metals to plastics; bonding very thin sections without distortion and very thin sections to thick sections; joining heatsensitive alloys; and producing bonds with unbroken surface contours.

The adhesive that bonds the component may serve as a sealant or protective coating. Adhesives can provide thermal or electrical insulating layers between the two surfaces being joined, and different formulations of the adhesive can make the bonding agent electrically conductive. These properties are highly adaptable to mass-produced printed circuit boards, and to the electrical and electronic components industry. Smooth, unbroken surfaces without protrusions, gaps, or holes can be achieved with adhesive bonding.

Typical examples of applications are the vinyl-tometal laminate used in the production of television cabinets and housings for electronic equipment. Other examples are automotive trim, hood and door panels, and roof stiffeners. The ability of flexible adhesives to absorb shock and vibration gives the joint good fatigue life and sound-dampening properties. A specific example is the improved fatigue life of adhesive-bonded helicopter rotor blades. A combination of adhesives and rivets for joints in very large aircraft structures has increased the fatigue life of joints from 2 x io5 cycles for rivets alone to 1.

The large bonded area also dampens vibration and sound. Adhesive bonding may be combined with resistance welding or mechanical fasteners to improve the loadcarrying capacity of the joint. The adhesive is applied to the adherents first. Then the components are joined together with spot welds or mechanical fasteners to hold the joints rigid while the adhesive cures. Figure A-3 illustrates typical design combinations. These techniques significantly reduce or eliminate fixturing requirements and decrease assembly time when compared to conventional adhesive bonding methods.

Adhesive bonding may permit significant weight savings in the finished product by utilizing lightweight fabrications. Honeycomb panel assemblies, used extensively in the aircraft industry and the construction field are excellent examples of lightweight fabrications. Although weight reduction can be important in the function of the product, adhesive bonding of products may also provide considerable labor and cost savings in packing, shipping, and installation.

Both destructive and nondestructive testing must be used with process controls to establish the quality and reliability of bonded joints.

Service conditions may be restrictive. Many adhesive systems degrade rapidly when the joint is both highly stressed and exposed to a hot, humid environment. Safe Practices. Adhesive bonding has certain limitations which should be considered in its application. Joints made by adhesive bonding may not support shear or impact 1oads. These joints must have an adhesive layer less than 0. The joints cannot sustain operational temperatures exceeding C F.

Capital investment for autoclaves, presses, and other tooling is essential to achieve adequate bond strengths. Process control costs may be higher than those for other joining processes.

In critical structural bonding applications, surface preparation can range from a simple solvent wipe to multi-step cleaning, etching, anodizing, rinsing and drying procedures; and joints must be fixtured and cured at temperature for some time to achieve full bond strength. Some adhesives must be used quickly after mixing. Nondestructive testing methods normally used for other joining.

Corrosive materials, flammable liquids, and toxic substances are commonly used in adhesive bonding. Manufacturing operations should be carefully supervised to ensure that proper safety procedures, protective devices, and protective clothing are being used. The material safety data sheet of the adhesive should be carefully examined before the adhesive is handled to ensure that the appropriate safety precautions are being followed. References: American Welding Society.

Welding Handbook, 8th Edition, Vol. Miami, Florida: American Welding Society, A term applied to a property exhibited by some of the light alloys, such as aluminum or magnesium, of hardening at ordinary temperatures after solution treatment or cold work. The controlling factors in age hardening are the composition of the material, degree of dispersion of the soluble phase, solution time and temperature, and aging time and temperature. A type of flux produced with a ceramic binding agent requiring a higher drying temperature that limits the addition of deoxidizers and alloying elements.

This is followed by processing to produce the desired particle size. A term applied to metals and particular alloys which show changes in physical properties on exposure to ordinary or elevated temperatures. A torch which produces a flame by burning a mixture of acetylene and air. The flame is as easily controlled and manipulated as the oxyacetylene flame, but has a lower temperature. The air-acetylene torch operates on the same principle as the Bunsen burner, that is, the acetylene flowing under pressure through a Bunsen jet draws in the appropriate amount of air from the atmosphere to provide combustion.

The flame is adjusted by controlling the amount of air admitted to the Bunsen jet. The mixer on the torch must be carefully adjusted to draw the correct volume of air to produce an efficient, clean flame. The air-acetylene flame ignites at C F and produces a maximum temperature of C F. The air-acetylene torch is used for brazing, soldering, and heating applications, but the flame temperature is not sufficient for welding, except for joining materials with a low melting point, like lead.

It is widely used for soldering copper plumbing fittings up to 25 mm 10 in. An oxyjkel gas welding process that uses an airacetylenesame. The process is used without the application of pressure. This is an obsolete or seldom used process. A nonstandard term for the nozzle of a flame spraying gun for wire or ceramic rod.

The air carbon arc cutting process uses an arc to melt metal which is blown away by a high-velocity jet of compressed air. The electrodes are rods made from a mixture of graphite and carbon, and most are coated with a layer of copper to increase their current-carrying capacity. Standard welding power sources are used to provide the current. In gouging operations, the depth and contour of the groove are controlled by the electrode angle, travel speed, and current.

In severing operations, the electrode is held at a steeper angle, and is directed at a point that will permit the tip of the electrode to pierce the metal being severed. In manual work, the geometry of grooves is dependent on the cutting operators skill. To provide uniform groove geometry, semiautomatic or fully automatic torches are used to cut U grooves in joints for welding, When removing weld defects or severing excess metal from castings, manual techniques are most suitable.

Voltage controlled automatic torches and control units are used for very precise gouging, with tolerances of less than 0. Reference: American Welding Society. Welding Handbook, Vol. The character of welding changes in aircraft construction with each technological advancement that affects any aircraft component. Because the materials and joining techniques and processes utilized in the aircraft industry are constantly changing and improving, it is vital that the most recent standards and current literature on the subject be used for reference.

While airplanes were largely hand-made metallic structures in the past, only the lighter planes have the welded steel fuselage that was once popular. Highspeed transports and military jets have a metallic skin to provide a monococque fuselage. Although rivets have been used to fasten the skin to the cell rings, spot welding also has an important role in the construction of this type of aircraft. Welding is the method that has the versatility to meet the varying conditions of joining members of varying sizes and weights which make up aircraft structures.

The aircraft structure, with its multiplicity of joints, must be light in weight and sufficiently strong to withstand severe conditions of service. The welded joint offers rigidity, simplicity, low weight, approximately full-strength joints, low corrosion possibilities, and relatively low-cost production equipment. Because of these advantages, welding is used for building all classes of airplanes, from light two-place pleasure planes to giant supersonic jets.

Welded tubular structures form the framework for the landing gear and the engine mounts. Requirements of the jet engine have introduced many areas in which welding plays an important role. Modern jet transports contain extremely high quality welds in the miles of duct work found in every jet plane. The welds are made by highly skilled gas tungsten arc welders in and aluminum, Inconel and nickel-base alloys, and 6AV titanium.

A pneumatic pressure device, sometimes adjustable, incorporated in the air-operating mechanism of a resistance welding machine to provide a deceleration of a mechanical motion. The chemical elements comprising an alloy.

In steel it is usually limited to the metallic elements added to steel to modify its properties. For example, the addition of copper, nickel, or chromium individually or in combination produces alloys or special steels.

A substance with metallic properties and composed of two or more chemical elements of which at least one is a metal. The added element may be metallic or nonmetallic. Powder prepared from a homogeneous molten alloy or from the solidification product of such an alloy. A thermal spraying process variation in which an air stream carries the powdered sugacing material through thegun and into the heat source.

See STAN-. A test specimen in which the portion being tested is composed wholly of weld metal. Three or more discontinuities aligned approximately parallel to the weld axis, spaced sufficiently close together to be considered a single intermittent discontinuity. A series of alloys developed for use as permanent magnets. With the exception of Alnico , all of these iron-base alloys contain aluminum, nickel, and cobalt as the principle alloying elements as the name Alnico indicates.

Because these alloys are available only in the cast or sintered condition, they are difficult to fabricate by welding. Yellow brass is the name used in metallurgical literature. Arrangement or position in line. To produce an accurate and serviceable weld when several parts are involved, an alignment jig is a necessity. The reversible phenomenon by which certain metals may exist with more than one crystal structure.

For example, alpha, gamma and delta iron are three allotropic forms of iron with different crystal structures. Abbreviation: ac, when used as a noun; a-c when used as an adjective. A current which reverses directions at regularly recurring intervals. Unless otherwise distinctly specified, the term alternating current refers. An arc welding process in which the power supply provides alternating current to the arc. A method of welding which makes use of the exothermic reaction which occurs when a mixture of aluminum and iron oxide powders is ignited.

When ignited, this mixture produces superheated liquid steel and aluminum oxide slag at approximately C F. The liquid steel is sufficiently hot to melt and dissolve any metal with which it comes in contact and fuses with it to form a solid homogeneous mass when cooled.

For this reason, this process is especially adapted to welding heavy steel and cast iron sections, such as those used in locomotive, marine, crankshaft and steel mill repairs, and is also used in pipe welding and rail welding. Atomic weight, Aluminum is one of the most abundant constituents of the earths crust. It is found in most clays, soils and rocks, but the principal commercial source is the ore, bauxite, an impure hydrated oxide.

The impurities are removed from bauxite by a chemical process leaving pure aluminum oxide, alumina. Pure metallic aluminum is obtained by electrolysis of the oxide. Aluminum is third on the scale of malleability and fifth in ductility. It is only slightly magnetic and is strongly electro-positive, so that when in contact with most metals it corrodes rapidly. Aluminum will take a high polish, but it is likely to become frosted in appearance due to the formation of an oxide coating.

Aluminum is used extensively as a deoxidizer in steel production, and as such it is an effective purifier. Aluminum lessens grain growth by forming dispersed oxides or nitrides. Commercial aluminum alloys are grouped into two classifications: wrought alloys and cast alloys. Wrought alloys are those alloys which are designed for mill products for which final physical forms are obtained by mechanical working, such as rolling, forging, extruding and drawing.

Wrought aluminum mill products include sheet, plate, wire, rod, bar, tube, pipe, forgings, angles, structural items, channels, and rolled and extruded shapes. Cast Alloys. Cast alloys are those alloys which are shaped into final form by filling a mold with molten metal and allowing it to solidify in the mold. Sand Casting. Sand casting utilizes a mold in sand made around a previously formed pattern to the exact shape desired in the final casting, but slightly larger in size to allow for shrinkage of the cast metal as it cools.

Permanent Mold Castings. Permanent mold castings are made by pouring molten metal into steel or iron molds. Die Castings. Die castings are also made in steel molds, but the molten metal is forced under pressure into the die or mold cavities. Die casting yields a denser casting with a better surface finish, closer dimensional tolerances, and thinner sections when desired. Clad Alloys. Copper and zinc, when used as major alloying elements, reduce the overall resistance to corrosion of aluminum alloys.

Wrought Alloy Designations. The Aluminum Association, an organization composed of manufacturers of aluminum and aluminum alloys, has devised a four-digit index system for designating wrought aluminum and wrought aluminum alloys.

The first digit indicates the alloy group, Le. The second digit indicates a modification of the original alloy, or the impurity limit of unalloyed aluminum. The third and fourth digits identify the alloy or indicate the aluminurn purity. In this index system, the letter following the alloy designation and separated from it by a hyphen indicates the basic temper designation. The addition of a subsequent digit, when applicable, refers to the specific treatment used to attain this temper condition.

Alloys which are hardenable only by cold working are assigned "H' designations; alloys hardenable by heat treatment or by a combination of heat treatment and cold work are assigned "T" designations. Table A-3 shows the basic temper designations and resulting condition of the alloy. Casting Alloy Designations. A system of four-digit numerical designations is used to identify aluminum casting alloys, as shown in Table A The first digit indicates the alloy group, the second two digits identify the aluminum alloy within the group, and the last digit which is separated from the first three by a period indicates the product form.

A modification of the original alloy or impurity limits is indicated by a letter before the numerical designation. The temper designation system for castings is the same as that for wrought product shown in Table A In brazing, specific fluxes and filler materials with melting points lower than that of the parent metal are used for making a joint without melting the pieces to be joined.

Brazing can be used to advantage when sections are too thin for welding, and for those assemblies having many parts which must be joined in an intricate manner. Brazing is generally lower in cost than gas or arc welding and is adaptable to mass production. Brazed joints have a smoother appearance, with wellrounded fillets which often require no finishing.

Brazed joints should be carefully designed to provide for full penetration of filler metal, because its flow depends largely on capillary action and gravity. Joints should be self-jigging for easy assembly prior to brazing. Lock seams, lap fillet, and T-joints are preferred because they have greater strength than butt or scarf joints. Three commonly used aluminum brazing methods are furnace, molten flux dip, and torch. Furnace Brazing. Furnace brazing consists of applying a flux and filter material to the workpieces, arranging them, then heating in a furnace to a temperature that causes the filler material to melt and flow into the joint without melting the parent metal.

Filler material in various forms is added to the joint. In many cases, filler material in the form of a flat shim or wire ring can be fitted into the joint. Filler material is also supplied by using clad brazing sheet, shaped to fit the joint. Standard types of furnace heating systems include forced air circulation, direct combustion, electrical resistance, controlled atmosphere, and radiant tube. The selection of furnace type is determined by the application requirements, as furnace operation and results vary.

For example, temperature is most easily controlled in electrical resistance furnaces. Although combustion furnaces are least expensive, some assemblies cannot be exposed to the gases which are always present in this type. Radiant heat furnaces are sometimes difficult to regulate, but the type of heat produced is excellent for most brazing requirements.

Aluminum-coated steel or firebrick linings are preferred for all types of heating units. Rate of production is another consideration when selecting a heating unit. In batch furnaces, brazing is accomplished by placing a tray of assemblies inside, heating for the required time, then removing the batch. Though simpler, this furnace is slower than the furnace with a continuous conveying system in which the work moves through on a belt.

The continuous furnace is more conservative of heat, and the gradual heating reduces danger of warping. Temperature for individual batches will necessarily depend on such factors as the design of the parts, size of fillets, and alloy to be brazed. However, furnaces should have operating temperature ranges from to C to "F , with control capability within k3"C 5F.

Since regulation of temperature is critical, automatic control is the rule in production. Applies to wrought products which are annealed to obtain the lowest strength temper, and to cast products which are annealed to improve ductility and dimensional stability.

The 0 may be followed by a digit other than zero. Applies to products of shaping processes in which no special control over thermal conditions or strain hardening is employed.

For wrought products, there are no mechanical property limits. An unstable temper applicable only to alloys which spontaneously age at room temperature after solution heat treatment.

Cooled from an elevated-temperatureshaping process and naturally aged to a substantially stable condition. Applies to products which are not cold worked after cooling from an elevated-temperature shaping process, or in which the effect of cold work in flattening or straightening may not be recognized in mechanical property limits.

Cooled from an elevated-temperatureshaping process, cold worked, and naturally aged to a substantially stable condition. Applies to products which are cold worked to improve strength after cooling from an elevated-temperatureshaping process, or in which the effect of cold work in flattening or straightening is recognized in mechanical property limits.

Solution heat treated, cold worked, and naturally aged to a substantially stable condition. Applies to products which are cold worked to improve strength after solution heat treatment, or in which the effect of cold work in flattening or straightening is recognized in mechanical DroDertv limits. Solution heat treated and naturally aged to a substantially stable condition. Applies to products which are not cold worked after solution heat treatment, or in which the effect of cold work in flattening or straightening may not be recognized in mechanical property limits.

Cooled from an elevated-temperature shaping process and then artificially aged. Applies to products which are not cold worked after cooling from an elevated-temperatureshaping process, or in which the effect of cold work in flattening or straightening may not be recognized in mechanical property limits.

Solution heat treated and stabilized. Applies to products which are stabilized after solution heat treatment to carry them beyond the point of maximum strength to provide control of some special characteristic. Solution heat treated, cold worked, and then artificially aged. Applies to products which are cold worked to improve strength, or in which the effect of cold work in flattening or straightening is recognized in mechanical property limits.

Solution heat treated, artificially aged, and then cold worked. Applies to products which are cold worked to improve strength. Cooled from an elevated-temperature shaping process, cold worked, and then artificially aged.

If uniform rise of temperature does not occur naturally, forced circulation is essential. Assemblies are generally placed in the furnace immediately after fluxing. When large areas have been fluxed, most of the moisture must be removed because the brazing process may be hindered if it is not removed.

Preheating the parts for about 20 minutes at approximately C F is usually sufficient. Brazing time depends on the thickness of the parts. For instance, material 0. After the filler material begins to melt, it takes approximately five minutes for the material to fill the joints.

Dip Brazing. Parts are assembled and dipped into a molten flux in dip brazing. This method has been very successful for the manufacture of elaborate assemblies, such as heat exchanger units. The flux application does not require a separate operation and the bath transmits heat to the interior of thin walled parts without overheating outside surfaces.

Contamination is also held to a minimum, Dip brazing is versatile. It is used in the manufacture of delicate specialty parts where tolerances up to k0.

A separate furnace is necessary to preheat the assembly to prevent undue cooling of the flux bath. A furnace used for furnace brazing operated at to C to F is satisfactory for preheating. It should be located near the dip pot so heat loss will be held to a minimum. Size of the dip pot will depend on the size of the assemblies to be brazed, but should be large enough to prevent the parts from cooling the flux more than 5C 10F below operating temperature when they are added.

Dehydration of the flux bath is accomplished by dipping or alloy sheet into it. As the sheet is attacked, the hydrogen evolved is ignited on the surface. Residue that forms on the bottom of the pot must be removed on a regular basis. A modification of dip brazing is the application of a flux mixture to the assembly prior to immersion in a salt bath furnace.

A typical example consists of making a paste of a mixture of a dry, powdered aluminumsilicon C ["F] flow point brazing alloy and flux, and water, and applying as much as required to fill the joints and make fillets.

Next, the assembly is placed in an oven and heated to about C F to remove the water. This leaves the brazing alloy powder firmly cemented to the aluminum surfaces, the flux serving as the cement.

When the assembly is placed in the molten brazing salt, the alloy is held firmly in place by the flux cement while it is being heated and melted. The flux cement has a higher melting point than either the brazing alloy or the brazing salt, but it is soluble in the salt bath, so the brazing alloy is held in place, even while melting, until the cement has been dissolved by the molten salt. As the flux cement is dissolved away from the molten filler metal, the alloy runs into the joint capillary spaces and also forms smooth fillets.

Torch Brazing. This method of brazing can be accomplished by using a standard torch as a heat source. Correct torch tip can best be determined through trial, and often depends on the thickness of the piece to be brazed. Filler alloys with suitable melting ranges and efficient fluxes are available for all brazeable aluminum alloys. A reducing flame with an inner cone about 25 mm 1 in. Oxyhydrogen, oxyacetylene, oxynatural gas, or gasoline blow torches can be used. Ample clearance space must be allowed where the filler will flow, and a path for flux to escape must be allowed.

Intended to give step-by-step guidance to institutions that want to build or convert facilities for welder training.

Order Code: GWF Includes practice questions similar to the exam questions, and the answers. Helps CWI chance to get involved. Join a committee! Includes test questions similar to the exam AWS Technical Committees and take your questions, and the answers.

Find out more at go. It is also B2. Qualification Includes addenda. Order Code: B2. These are the same tools used in the B2. Identical to Annex C of B2.

FREE Download at go. This B2. Adopted by NBIC. Practical exercises allow welders, welding students, supervisors and inspectors to apply basic math skills to various aspects of the welding process see page 6 18 Lesser price shown is for AWS members.

Hard Copy Order Code: B5. The written and problem solving. This guide contains recommendations for establishing a Order Code: B5. Information related to training, knowledge and skill testing, and coating B5.

This standard also covers the levels processes. ANSI Approved. Welding Sales Representative. Order Code: B5. Cutting, and Thermal Spraying. The revisions in this Order Code: QC Order Code: D Order Code: QC Order Code: EG3. Order Code: QC7F Welding Supervisors Order Code G1. This self-paced interactive online program combines Order Code: QC Register at awo. Focuses on safety in welding, cutting 24 pages.

Presented CMWS, Certified Welding Supervisor in 13 interactive and engaging modules, this seminar is Manual for Quality and Productivity perfect for both inside and outside salespeople, distributors, Improvement see page 17 manufactures, supervisors, managers, and any other professional that wants to gain a technical understanding of CM, Certification Manual for Welding welding principles, methodology, equipment, consumables, Inspectors see page 17 and variables.

The standard also addresses which method best detects various types of discontinuities. The methods B4. Sketches and color photographs illustrate common weld discontinuities. Order Code: C4. Includes gouging Oxygen-Cut Surfaces, and Oxygen Cutting recommendations and a handy troubleshooting guide. Consists of a plastic gauge with samples of oxygen-cut Order Code: C5.

Typical mechanical property data are referenced. Complete lists of equipment are C6. Welding of Metals Order Code: C4. Includes Describes methods and techniques for shaping and sections on safety, process fundamentals, equipment straightening metal parts including steel plate, pipes, and maintenance, metallurgical and general process angles, channel, T bar, and compound structures considerations, inspection and testing of welds, training by careful application of heat.

Topics include oxyfuel gas equipment torches, curves for various alloys. Also discusses electron beam tips, regulators, fuel gases, gas cylinders, and bulk braze welding, cutting, drilling, surfacing, additive supply ; torch procedures for spot, line, and V heating manufacturing, surface texturing, and heat treating.

Describes Comparison of standardized methods for the avoidance equipment and procedures. Practical information, of cold cracks.

Order Code: C7. Explains processes, equipment, materials, workshop practices, joint preparation, welding technique, C1. Order Code G2. A weldability test is described, practices for joining zirconium parts.

Order Code: G2. Presents current practices for heat transfer, thermoplastics, weldability studies, and optimizations. Its intent is to make possible a generally Order Code: D Not applicable to tank car tanks or rails.

Covers repair procedures for rails and austenitic manganese steel components, thermite welding, electric B2. Thermoplastics Order Code: D Order Code: G1.

Describes the test methods used to obtain reliable data on Order Code: C3. Criteria for classifying aluminum This standard lists the necessary steps to assure the brazed joints based on loading and the consequences of suitability of brazed components for critical applications. It is the intent of this document to identify and explain these common considerations and C3. Provides the Order Code: C3. Criteria alloys is addressed in AWS C3.

Describes relevant equipment, fabrication procedures, Order Code: C3. It also provides quality of acceptability in each class. Order Code: C3. Instructors and students can consider this the basics of brazing, processes, and guideline as a reference text to instruction manuals, work applications.

Addresses the fundamentals control procedures, and drawings. A must-have for all brazers, brazing engineers, processes. Individual chapters of both books are now available as a PDF download from aws. All other vertical position passes are up hill. All licenses are good for unlimited intracompany applications.

Its purpose is also t present Order Code: D It applies to both D Joint designs, assembly, consumable insert Russian edition Applicable arc welding processes and D The delta ferrite content Contains recommended practices for welding piping as expressed by ferrite number FN is explained, and systems of sizes DN NPS 8 and under and wall its importance in minimizing hot cracking is discussed.

Appendix A presents information on the as well as some gas and chemical systems. Does not address the needs of pipe steels or service conditions that may require postweld heat Incorporates results of research on the effects of treatment. Provides coverage 10 tables. Contains criteria for D Extensive guidance on multipass orbital machine Order Code: D Emphasis is sion resistance and higher mechanical strength of duplex placed on maintaining interpass temperature and dangers stainless steels.

The metallurgy of duplex stainless steels inherent in interrupted heating cycles. Suitable as a specifying tool and visual examination D May also be applied to maintenance of Sanitary Hygienic Applications food processing equipment. Order Code: A4.