|
Resistance Seam Welding
Electric resistance welding (ERW) is a welding process in which metal parts in contact are permanently joined by heating them with an electric current, melting the metal at the joint. Electric resistance welding is widely used, for example, in manufacture of steel pipe and in assembly of bodies for automobiles. The electric current can be supplied to electrodes that also apply clamping pressure, or may be induced by an external magnetic field. The electric resistance welding process can be further classified by the geometry of the weld and the method of applying pressure to the joint: spot welding, seam welding, flash welding, projection welding, for example. Some factors influencing heat or welding temperatures are the proportions of the workpieces, the metal coating or the lack of coating, the electrode materials, electrode geometry, electrode pressing force, electric current and length of welding time. Small pools of molten metal are formed at the point of most electrical resista ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Welding
Welding is a fabrication (metal), fabrication process that joins materials, usually metals or thermoplastics, primarily by using high temperature to melting, melt the parts together and allow them to cool, causing Fusion welding, fusion. Common alternative methods include solvent welding (of thermoplastics) using chemicals to melt materials being bonded without heat, and #Solid-state welding, solid-state welding processes which bond without melting, such as pressure, cold welding, and diffusion bonding. Metal welding is distinct from lower temperature bonding techniques such as brazing and soldering, which do not melt the base metal (parent metal) and instead require flowing a filler metal to solidify their bonds. In addition to melting the base metal in welding, a filler material is typically added to the joint to form a pool of molten material (the weld pool) that cools to form a joint that can be stronger than the base material. Welding also requires a form of shield to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stainless Steel
Stainless steel, also known as inox, corrosion-resistant steel (CRES), or rustless steel, is an iron-based alloy that contains chromium, making it resistant to rust and corrosion. Stainless steel's resistance to corrosion comes from its chromium content of 11% or more, which forms a Passivation (chemistry), passive film that protects the material and can self-healing material, self-heal when exposed to oxygen. It can be further alloyed with elements like molybdenum, carbon, nickel and nitrogen to enhance specific properties for various applications. The alloy's properties, such as luster and resistance to corrosion, are useful in many applications. Stainless steel can be rolled into Sheet metal, sheets, plates, bars, wire, and tubing. These can be used in cookware, cutlery, surgical instruments, major appliances, vehicles, construction material in large buildings, industrial equipment (e.g., in paper mills, chemical plants, water treatment), and storage tanks and tankers for ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shot Welding
Shot welding is a type of electric resistance welding which, like spot welding, is used to join two pieces of metal together. The distinguishing feature is that in shot welding, strips and sheets of metal (usually stainless steel) are "sewed" together with rows of uniform spot welds. The weld is achieved by clamping the two pieces together then passing a large electric current through them for a short period of time. Shot welding was patented by Earl J. Ragsdale, a mechanical engineer at the Edward G. Budd Manufacturing Company in 1932 to weld stainless steel. This welding method was used to construct the first stainless steel train, ''Pioneer Zephyr'', in 1934, and became the standard construction technology for railroad passenger cars thereafter. Method In the early 20th century, the Edward G. Budd Manufacturing Company had been innovative in the field of sheet metal fabrication, and had revolutionized the construction of automotive bodies in steel during the 1920s. Edwar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Welding Processes
This is a list of welding processes, separated into their respective categories. The associated ''N reference numbers'' (second column) are specified in ISO 4063 (in the European Union published as ''EN ISO 4063''). Numbers in parentheses are obsolete and were removed from the current (1998) version of ISO 4063. The AWS reference codes of the American Welding Society are commonly used in North America."Welding Inspection Handbook", 3rd edition, American Welding Society, , Miami, FL, pp. 10-11 (2000) Arc welding ''Overview article: arc welding'' Oxyfuel gas welding ''Overview article: Oxy-fuel welding and cutting'' Resistance welding ''Overview article: electric resistance welding'' Solid-state welding Other types of welding Notes and references *Cary, Howard B. and Scott C. Helzer (2005). Modern Welding Technology. Upper Saddle River, New Jersey: Pearson Education. . *Lincoln Electric (1994). The Procedure Handbook of Arc Welding. Cleveland: Lincoln Electric. . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stud Welding
Stud welding is a technique similar to flash welding where a fastener or specially formed nut is welded onto another metal part, typically a base metal or substrate. The fastener can take different forms, but typically fall under threaded, unthreaded, or tapped. The bolts may be automatically fed into the stud welder. Weld nuts generally have a flange with small nubs that melt to form the weld. ''Weld studs'' are used in stud welding systems. Manufacturers create weld studs for the two main forms of stud welding: capacitor discharge stud welding and drawn arc stud welding Drawn arc stud welding Drawn arc stud welding joins a stud and another piece of metal together by heating both parts with an arc. The stud is usually joined to a flat plate by using the stud as one of the electrodes. The polarity used in stud welding depends on the type of metal being used. Welding aluminium, for example, would usually require direct-current electrode positive (DCEP). Welding steel would re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Arc
An electric arc (or arc discharge) is an electrical breakdown of a gas that produces a prolonged electrical discharge. The electric current, current through a normally Electrical conductance, nonconductive medium such as air produces a plasma (physics), plasma, which may produce visible light. An arc discharge is initiated either by thermionic emission or by field emission. After initiation, the arc relies on thermionic emission of electrons from the electrodes supporting the arc. An arc discharge is characterized by a lower voltage than a glow discharge. An archaic term is voltaic arc, as used in the phrase "voltaic arc lamp". Techniques for arc suppression can be used to reduce the duration or likelihood of arc formation. In the late 19th century, Arc lamp, electric arc lighting was in wide use for Street light#Arc lamps, public lighting. Some low-pressure electric arcs are used in many applications. For example, fluorescent lamp, fluorescent tubes, mercury, sodium, and met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Resistance And Conductance
The electrical resistance of an object is a measure of its opposition to the flow of electric current. Its Multiplicative inverse, reciprocal quantity is , measuring the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with mechanical friction. The International System of Units, SI unit of electrical resistance is the ohm (), while electrical conductance is measured in siemens (unit), siemens (S) (formerly called the 'mho' and then represented by ). The resistance of an object depends in large part on the material it is made of. Objects made of electrical insulators like rubber tend to have very high resistance and low conductance, while objects made of electrical conductors like metals tend to have very low resistance and high conductance. This relationship is quantified by electrical resistivity and conductivity, resistivity or conductivity. The nature of a material is not the only factor in resistance and conductance, howev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Current
An electric current is a flow of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is defined as the net rate of flow of electric charge through a surface. The moving particles are called charge carriers, which may be one of several types of particles, depending on the conductor. In electric circuits the charge carriers are often electrons moving through a wire. In semiconductors they can be electrons or holes. In an electrolyte the charge carriers are ions, while in plasma, an ionized gas, they are ions and electrons. In the International System of Units (SI), electric current is expressed in units of ampere (sometimes called an "amp", symbol A), which is equivalent to one coulomb per second. The ampere is an SI base unit and electric current is a base quantity in the International System of Quantities (ISQ). Electric current is also known as amperage and is measured using a device called an ''ammeter''. Electric currents creat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Material Properties
A material property is an intensive property of a material, i.e., a physical property or chemical property that does not depend on the amount of the material. These quantitative properties may be used as a metric by which the benefits of one material versus another can be compared, thereby aiding in materials selection. A property having a fixed value for a given material or substance is called material constant or constant of matter. (Material constants should not be confused with physical constants, that have a universal character.) A material property may also be a function of one or more independent variables, such as temperature. Materials properties often vary to some degree according to the direction in the material in which they are measured, a condition referred to as anisotropy. Materials properties that relate to different physical phenomena often behave linearly (or approximately so) in a given operating range . Modeling them as linear functions can significant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filler Metals
In metalworking, a filler metal is a metal added in the making of a joint through welding, brazing, or soldering. Soldering Soldering and brazing processes rely on a filler metal added to the joint to form the junction between the base metal parts. Soft soldering uses a filler that melts at a lower temperature than the workpiece, often a lead-tin solder alloy. Brazing and hard soldering use a higher temperature filler that melts at a temperature which may approach that of the base metal, and which may form a eutectic alloy with the base metal. Filler alloys have a lower melting point than the base metal, so that the joint may be made by bringing the whole assembly up to temperature without everything melting as one. Complex joints, typically for jewelry or live steam boilermaking, may be made in stages, with filler metals of progressively lower melting points used in turn. Early joints are thus not destroyed by heating to the later temperatures. Welding Welding processes wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upset Welding
Upset welding (UW)/resistance butt welding is a welding technique that produces coalescence simultaneously over the entire area of abutting surfaces or progressively along a joint, by the heat obtained from resistance to electric current through the area where those surfaces are in contact. Pressure is applied before heating is started and is maintained throughout the heating period. The equipment used for upset welding is very similar to that used for flash welding. It can be used only if the parts to be welded are equal in cross-sectional area. The abutting surfaces must be very carefully prepared to provide for proper heating. The difference from flash welding is that the parts are clamped in the welding machine and force is applied bringing them tightly together. High-amperage current is then passed through the joint, which heats the abutting surfaces. When they have been heated to a suitable forging temperature an upsetting force is applied and the current is stopped. The hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Projection Welding
Spot welding (or resistance spot welding) is a type of electric resistance welding used to weld various sheet metal products, through a process in which contacting metal surface points are joined by the heat obtained from resistance to electric current. The process uses two shaped copper alloy electrodes to concentrate welding current into a small "spot" and to simultaneously clamp the sheets together. Work-pieces are held together under pressure exerted by electrodes. Typically the sheets are in the thickness range. Forcing a large current through the spot will melt the metal and form the weld. The attractive feature of spot welding is that a large amount of energy can be delivered to the spot in a very short time (approximately 10–100 milliseconds). This permits the welding to occur without excessive heating of the remainder of the sheet. The amount of heat (energy) delivered to the spot is determined by the resistance between the electrodes and the magnitude and duration of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
