Use of electroslag welding in highway bridges and structures. Because of the slow cooling rate, cold cracking is. The following are free downloadable pdfs available to all users. Electroslag and electrogas welding12 welding, brazing and. An electric arc is initially struck by wire that is fed into the desired weld location and then flux is added. Electroslag welding esw a welding process that produces coalescence of metals with molten slag that melts the filler metal and the surface of the workpieces.
In consumable selection for essc, the strip width needed eelctroslag the application is determined by the size and shape of the components to be surfaced. There are several types of welding processes similar to. Electroslag welding esw is a highly productive, single pass welding process for thick greater than 25 mm up to about 300 mm materials in a vertical or close to vertical position. Prior to welding the gap between the two work pieces is filled with a welding flux. In this process consist of two cooled copper shoes and its clamped along with side of thick work piece. Electroslag strip cladding offers productivity and cost benefits. Proses pengelasan esw electroslag welding dan egw electrogas welding dasar dasar pengelasan. Alcohol on a manual arc welding task, the effect of d. Prevention of esw shoes from becoming welded to base metal. Chapter 10 from the welding handbook, ninth edition, volume 2, welding processes, part 1, has been selected by the aws product development committee as a service to industry professionals. Electroslagwelding, cost effective vertical one pass. Initially, electroslag welding was patented in the united states in 1938 and later in 1940 as the hopkins process after its inventor, r. Electrogas welding pdf one of the welding processes that used in engineering field is the electrogas welding.
Electroslag welding is a nonarc welding process utilizing an electrical current that passes between a consumable electrode and a work piece. Thermite welding uses an exothermic reaction to produce molten steel which is cast between two rails to be joined. This reduced heat input and increased travel speed produced more uniform heat affected zone. The submerged arc weldingsaw and electroslag welding. Click on a document, and you can download the pdf to your pc. Electroslag welding esw and electrogas welding egw are two related procedures. The project investigated the feasibility of field welding railroad rail with the electroslag welding esw process. Electrogas welding egw is a method of gas metal or flux cored arc welding, wherein an external gas is supplied to shield the arc, and. An electric arc is initially struck by wire that is fed into the desired weld location and then flux is added the slag reaches a. Flux is added, which then melts by the heat of the arc.
The main difference is that the arc is started between the electrode tip and the bottom of the part to be welded. When the molten slag is melt the thick work piece and filler materials. Bab ini menjelaskan mengenai prosesproses pengelasan yang banyak dipakai oleh berbagai perusahaan, beserta keunggulan, kelemahan, dan masingmasing aplikasinya. A parametric study of the electroslag welding process citeseerx.
After the molten slag reaches the tip of the electrode, the arc is extinguished. Esw is similar to electrogas welding, but the main difference is the arc starts in a different location. A shielding gas is sometimes used, but pressure is not applied. Electrogas welding egw is a high productivity process derived and adapted from the older electroslag welding, esw. Some applications of electroslag welding are stated below. Submerged arc welding saw electroslag welding esw 3. This chapter describes the electroslag welding esw process and its process variation, consumable guide electroslag welding esw cg.
Electroslag welding for stiffeners in ibeam anf box columns. It is classified as a machine welding process, because for its operation requires special equipment. Electroslag cladding provides alternative to standard. Boilercastingenergyengineequationforcefuelheatjoining processlawmachinemachining. As of late, new methods of electroslag welding have been tried, and narrow gap improved electroslag welding ngi esw was created with the hopes of meeting the toughness requirements of zone 2 bridges. This article discusses the fundamentals of the electroslag process in terms of heat flow conditions and metal transfer and weld pool morphology. Thus the molten metal pool is shielded by molten slag.
Training manual for narrowgap improved electroslag welding, fhwasa96. A conventional automated technique is submerged arc strip cladding sasc, but this isnt the only process. The process is initiated by an arc that heats up the slag. When this method of welding is being performed, a liquefied slag that covers the surface of the weld conducts the electrical current. Electroslag welding is a nontraditional welding process in which molten metal pool is created.
It is a highly productive, single passing welding process for thick material of about 25mm to about 300mm. Electroslag welding is an arc welding process that generate heat by an electric current. Electroslag welding esw of steels total materia article. Electroslag welding esw is a highly productive, single pass welding process for thick greater. Electroslag welding esw has been of interest for many years, because it pro vides one of the highest rates of weld metal deposition.
This method is combination of both arc welding and resistance welding because at starting, heat is generated by establishes an arc between electrode and base metal as in arc welding. For convenience of discussion, it is grouped with arc welding processes. Dmitri kopeliovich electroslag welding is a welding process, in which the heat is generated by an electric current passing between the consumable electrode filler metal and the work piece through a molten slag covering the weld surface. Electroslag welding esw electroslag welding is the welding process in which the heat is generated by an electric current passing between the consumable electrode filler metal and the work piece through a molten slag, which covers the weld surface.
The electroslag welding esw process involves a molten slag that melts the filler metal. Electrogas welding egw is a continuous vertical position arc welding process developed in 1961, in which an arc is struck between a consumable electrode and the workpiece. Recent advances in field electroslag rail welding authors. Electroslag welding is a welding process, in which the heat is generated by an electric current passing between the consumable electrode filler. Even when cold welding, a welder should wear a mask, gloves, and approved clothing. Use of electroslag welding in highway bridges and structures fhwa. The welding process is used to weld large casting and forging when producing a large composite structure. Built on over 60 years of experience designing and manufacturing welding simulators, the gleeble welding simulator provides a complete platform for a wide range of welding simulations and testing capabilities including weld haz simulation, hot tensile testing, nilstrength determination and much more. Electroslag welding an overview sciencedirect topics. For example, gas tungsten arc welding gtaw is not wellsuited to cladding large items or areas that need a large amount of.
Electrogaswelding, advantageous choice for suitable joints. Electroslag and electrogas welding asm international. Consumable guide electroslag welding of 4 to 24 inch. Electroslag welding is a process providing one of the highest weld deposition rates and is therefore most costeffective for suitable applications its unique capability permits to weld in one pass groove joint of two plates, thick 1 to 12 inches 25 to 300 mm and more. Fracture strength of electroslag welding joint with high. The electroslag welding esw process is a potentially attractive operation for the welding of thick plates needed in the construc tion of ships, storage tanks, pressure vessels, bridges, buildings and other structures i 41. Electroslag and electrogas welding of cmn steel twi.
The new process utilized a narrower gap and a fixed, consumable, electrode guide in combination with reduced voltages and higher welding currents. Electroslag welding is a fusion welding process for joining thick work pieces by a single. Filler metal placed at the joint root before welding, and intended to be completely fused into the joint root to become part of. Electroslag welding is capable of welding plates with thicknesses ranging from 50 mm to more than 900 mm and welding is done in one pass. The electroslag welding esw process, the metal coalescence produced by molten slag.
The electrode is guided into the weld area by either a consumable electrode guide tube, like the one used in electroslag welding, or a moving head. Electroslag welding esw the electroslag welding esw process involves a molten slag that melts the filler metal and the surfaces of the workpieces to be joined. Electroslag welding esw applications are similar to electrogas welding. The multiple consumable guide electroslag welding esw process provides. Full details about the various welding processes can be found in the cwb modules. Temperature profiles, the size of the heataffected zone. Electroslag welding esw is a highly productive, single pass welding process for thick greater than 50 mm materials in a vertical or close to vertical position. Electrogas welding egw is an vertical positioned arc welding process, is used for welding the edges of sections vertically and in one pass with the pieces placed edge to edge butt joint. When esw is used to surface machine parts, metalcored tubular wire. Applications, advantages and disadvantages of electroslag. The original purpose of developing egw was of adapting the esw process for welding thinner plates.
The benefits sought were high deposition rates and efficient welding. The weld pool is shielded by this slag which moves along the full cross section of the joints as welding progresses. What is electroslag welding and its working principles. Kemudian dijelaskan juga mengenai disain sambungan dan jenisjenis sambungan. Esw process are appropriate for applying welded deposits over large surface areas by means of. A constant current cc welding machine is one which has a static. The overlaying with a strip electrode, socalled bandoverlaying, features the use of thin, wide strip electrodes in combination with fluxes instead of wire electrodes for submerged arc welding saw and electroslag welding esw as illustrated in figure 1. In ultrasonic welding what creates heat for welding. Lec 14 electroslag and electrogas welding duration. Single or multiple solid as well as fluxcored electrodes may be used. Electroslag welding esw is a singlepass fullpenetration verticalup process in which the heat is generated not by an arc but by the resistance of a molten slag pool at the top of the weld.
A major difference between egw and its cousin electroslag welding is that the arc in egw is not extinguished, instead remains struck throughout the welding. Dia 750 mm electro slag strip clading id overlay by 60 x 0 5 mm. A method of electroslag welding in which filler metal is supplied by an electrode and its guiding member. Owing to the large heat input, the ductility and notch toughness of esw joints are prone to degradation. Electroslag welding esw and electrogas welding egw are two related procedures that are used to weld thicksection materials in the vertical or nearvertical position between retaining shoes. Cladding, often used in manufacturing or repair, is a good way to conserve an expensive alloy. Electroslag welding was derived from a metal manufacturing process called electroslag remelting or refining esr. Electroslag welding esw involves high energy input relative to other welding processes, resulting generally in inferior mechanical properties and specifically in lower toughness of the heataffected zone. Submerged arc, electroslag welding counters process. Weld cladding techniques can be manual or automated. The electroslag welding esw process has some characteristics of submerged arc welding in that it is used. Consumable electrode is used and the weld surface is covered with a molten slag. Plasma arc welding paw electroslag welding esw electrogas welding egw stud welding sw the letter designation may be used to identify the process.
Electron beam welding ebw laser beam welding lbw since there is no arc involved in the electroslag welding process, it is not exactly an arc welding process. Because the weld is made in a single pass for virtually unlimited thickness, its deposition rate is many times higher than the dominant bridge. An electric arc is initially struck by wire that is fed. Two processes currently dominant the market, thermite and flashbutt welding. Electroslag welding easily lends itself to mechanization, thus reducing the requirement for skilled manual welders. It is used for welding parts with thick walls with large diameter parts, pressure vessels, storage tanks and ships.