A method for a routine, direct analysis for fluoride in electroslag refining esr fluxes, using potentiometry, is described that is faster, more economical, and less operatordependent than previously known methods of fluoride analysis in these materials. The task of producing highquality large ingots from highalloy steels and alloys has not as yet been completely fulfilled. Refinement of grain size by inoculation during electroslag refining esr is known to improve the mechanical properties of 15cdv6 and modified 15cdv6 steels. The process is intoated by that up the bux forms the slag. It was found that the removal efficiency of electroslag refining for. 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.
The present work examines a new method of introducing inoculant during esr, resulting in higher recovery of the inoculant. Prior to welding the gap between the two work pieces is filled with a welding flux. Electroslag remelting for the production of tool steels. It is also used to describe three separate processes, using the principle of electroslag namely i consumable electrode metal refining and cost structure improvement process ii the semicontinuous or 11. However, since uranium is a very active and highly toxic metal, electroslag melting must be conducted in a closed system with a protective environment of an inert gas. For this purpose, oxygen was introduced into titanium during chamber electroslag remelting by three different methods. If you need to print pages from this book, we recommend downloading it as a pdf. Fluoride containing slag, which influences the nonmetallic inclusions to a great extent, has been widely used for the electroslag remelting process.
The molten steel in form of both liquid film on the electrode tip and descending droplets contacts with the slag and get refined due to desulfurization and removal of nonmetallic inclusions sulfides and oxides. Us3389208a us63611767a us3389208a us 3389208 a us3389208 a us 3389208a us 63611767 a us63611767 a us 63611767a us 3389208 a us3389208 a us 3389208a authority us. Drops of the molten electrode metal pass through the slag layer to form a layer of metal underneath. Cast electrodes of commercial aluminum were electroslag refined using kclnaclna 3 alf 6 slag containing na 2 b 4 o 7. During electroslag remelting, the temperature of the slag, which consists of various components caf 2, cao, sio 2, al 2 o 3, and others, exceeds 2500c. Flux 37s is used together with strip electrodes of the cr. Electro slag remelting esr ald vacuum technologies.
Influence of oxygen addition on structure and properties of. Esr is a continuous process, where during the remelting of the consumable electrode, refining and solidification of the steel occur simultaneously. Ingots up to 200 metric tons are produced by electroslag remelting utilizing simultaneous remelting of tens of electrodes. Printed m gri britain effect of electroslag refining on the fracture toughness and fatigue crack propagation rates in heat treated aisi 4340 steel mohan g. Consumableguide welding is a much simplified version of electroslag welding. It is known that metal which is produced by the method of electroslag remelting esr has service properties superior to those of metal made by open refining and casting. Initial trials have demonstrated the viability of electroslag crucible melting for producing cast alloys with low impurity content and superior tensile properties.
Report of the committee on electroslag remelting and plasma. The electroslag melting process page 214 unt digital. It dispenses completely with the rising and gating. An introduction to premium melting carpenter technology. Electroslag cladding provides alternative to standard cladding techniques. Mar 11, 1975 this invention relates to the electroslag refining process and to apparatus for use therewith.
Download fulltext pdf electroslag refining of crnimowmnv ultrahighstrength steel article pdf available in journal of minerals and materials characterization and engineering 0506. Unit for electroslag remelting of metals and alloys with high reaction ability under active metalcontaining fluxes in controlled atmosphere or vacuum. Electroslag remelting furnaces in the 1960s consarcs engineers conceived a new approach to electroslag remelting, quite different from others in use at the time. Electroslag crucible melting of age hardening copper. Esr electroslag remelting is the abbreviated name given to electroslag consumable electrode remelting and secondary refining process. Electroslag technology of production of large forging.
Barrancos mooney pdf cladding electroslga typically a very continuous operation that requires high amperages and high duty cycles. Electroslag remelting furnaces for more information visit. In the electroslag refining process, an electricallyconductive slag within a mould is maintained in a molten state and at a temperature above the melting point of the metal to be refined. Electroslag refining of crnimowmnv ultrahighstrength steel. The electroslag melting process page 12 unt digital. Unfortunately, this book cant be printed from the openbook. Since the choice of flux is a unique parameter in the electroslag process, two chapters are developed to this subject. Although electroslag welding is mainly used for the joining of mild and lowalloy steels, satisfactory welds have been made in highalloy steels, titanium and aluminium. Test methods for electroslag remelting furnaces are specified in iec 60779. The current required is about 600 a at 40 to 50 volts although higher currents are used for thick plates. Electroslag remelting an electrometallurgical process in which a metal in the form of a consumable electrode is remelted in a bath of an electrically conducting synthetic slag by the action of heat released upon the passage of electric current through the slag. Removal of iron from commercial aluminum by electroslag. This bulletin traces the development of the electroslag melting process from its modest beginnings to the present.
Electroslagwelding, cost effective vertical one pass. Esr refining potential for titanium alloys using a caf2. It gives excellent slag removal and bead appearance also for nballoyed strip electrodes. The objectives of the research reported herein include 1 testing the feasibility of preparing very lowsulfur steels electroslag and electricarcfurnace processes, 2 evaluating the possibility of eliminating an external desulfurization step in the electricarcfurnace process to produce such steels, 3. Esr refining potential for titanium alloys using a caf 2. The resulting improvements in the efficiency and performance of the process established consarc as the leading manufacturer of esr systems worldwide. A method of forming an ingot of refined metal by the electroslag refining process comprises the steps of introducing into the lower open end of a cooled mould a solid uncooled electricallyconductive member of a material weldably compatible with the metal to be refined, the member having a surface area sufficient to conduct the full working current employed in the process. The electroslag refining esr process is one of the most important secondary refining processes owing to its relatively low production cost, low capital investment and ability to produce high quality steel with desired chemistry and homogenous structure. Computational modeling of the electroslag remelting esr. Introduction this process was developed originally in the erstwhile ussr in 1930. Applies to electroheat installations for remelting and, in some cases, for refining processes of metals through direct resistance heating of a conductive slag. Evaluation of the electroslag remelting process in medical grade of 316lc stainless steel s. Electroslag remelting esr, also known as electroflux remelting, is a process of remelting and refining steel and other alloys for missioncritical applications in.
The influence of esr on improvement in service properties of 20hgs2h steel, in remelting for refining, naukova dumka, kiev, pp. It is also found that the ductility, impact toughness and. The electroslag remelting esr process is a foundry method to refine and mold molten metals based. Us6350293b1 bottom pour electroslag refining systems and. The watercooled copper mold provides relatively high gradient of temperature resulting in. The electroslag refining process esr is a variant of the group of consumable electrode remelting processes esr, var, ebr and par for producing ingots of higher quality than that of the original material by means of controlled solidification and chemical refining.
Journal of minerals and materials characterization and engineering, 2017, 5, 385407. Metallurgy of the electroslag remelting process due to the superheated slag that is continuously in touch with the electrode tip, a liquid film of metal forms at the electrode tip. The electro slag refining process esr is a variant of the group of consumable electrode remelting processes esr, var, ebr and par. Electroslag welding an overview sciencedirect topics. Refining usually results in the elimination of a number of casting or solidification defects, such as shrinkage porosity, gas porosity, pipe, micro and macro segregation. Despite it is one of the most abundant elements in the earths crust, it is. The method, which significantly increases the quality of the metals and alloys produced, was.
Nov 26, 2015 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 droplets enters the molten steel pool, bottom of which is progressively solidifying. Designs and manufactures furnace systems for a variety of metallurgical processes, including. The electroslag melting process page 214 digital library. The electroslag remelting esr process is used to remelt and refine steels and various super.
In the refining process, a slag or flux is used both as a heat source and as a refining medium. This report is based upon the electroslag refining esr operations undertaken by the commonwealth steel company, waratah, nsw, and draws upon detailed technical records of both production and experimental operations over an extended period. Important basic mechanisms such as electrochemistry, thermochemistry, and heat transport are described. Removal of nonmetallic inclusions from aluminum by electroslag. The bottom pour electroslag refining system comprises an electroslag refining crucible. Electroslag remelting its status, mechanism and refining.
Pdf the electroslag remelting process esr is important because it provides better control of the solidification. The effect of electroslag refining on iron reduction from commercial aluminum was investigated. Effect of electroslag refining on the fracture toughness and. The electroslag refining technique is one of the modern tools which is capable of imparting superior mechanical and chemical properties to metals and alloys. Effect of inoculation during electroslag refining on grain. 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. The gestation period was long and torturous going from principles written down in 1892 to actual research in 1935 to full. State key laboratory of advanced metallurgy, university of science and technology beijing, beijing 83, china. Equipment used for electroslag welding operations 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. Using of electroslag technology for refining of titanium and alloys on its base from nitrogenrich inclusions. The mounting ring supports the starter in a crucible below an ingot being electroslag refined. Effects of electroslag refining on removal of iron impurity and alumina inclusions from aluminum were studied on a laboratoryscale apparatus.
Electroslag melting is also known as electroflux melting is a process of melting and refining steel and super alloys for mission critical application. Titanium production by magnesium thermal reduction in the. Figure 1 shows a schematic diagram of the esr process that uses a stationary. Electro slag remelting esr is a process used for remelting and refining of steels and special alloys which are used for critical applications in aircraft, thermal and nuclear power plants, defense hardware, etc. Electroslag refining 10 is a secondary refining process already well established for ferrous materials. Pdf electroslag refining of crnimowmnv ultrahighstrength steel. With every increase of the requirements of the users and the properties of thick plates and forgings and the appropriate increase of the complexity of the alloying systems of steel and alloys this problem becomes more acute, in particular in the production of certain. Unrefined metal is introduced into the mould and is refined as it passes in.
The technology of electroslag remelting esr meets these demands. The electroslag crucible melting process, developed on the well established principles of electroslag refining, has been used to cast age hardening cu05cr alloys using copper scrap. Determination of total fluoride content in electroslag. Review on desulfurization in electroslag remelting esr. After passing through the flux, the alloy slowly cools down and solidifies again into a remelted ingot 1, 2, 3,4,5. This simplification stems mainly from the use of a wire guide. Rezaei3 1 institute of advanced technologies for metallic materials, tarbiat modares university, tehran, iran. Influence of oxygen addition on structure and properties. An electroslag refining starter includes a refined disk fixedly joined in a central aperture of a mounting ring. 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. The disk is consumed during starting and is replaceable in the same mounting ring for subsequent reuse.
An electric arc is initially struck by wire that is fed. Another timesaving benefit of the essc process stems from the electroslag refining that occurs when the molten metal passes through the slag bath. Since the usa patent of electroslag remelting esr metallurgy was held by p. Unlimited viewing of the articlechapter pdf and any associated supplements and figures. 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. Evaluation of the electroslag remelting process in medical. Electroslag welding a gocess ft19co of meta as as filler metal is achieved from heat 9ervaed the resgance of mciten slag, weld pod shielded motten wt. This can be attributed to the better conditions which exist for refi ning in the specially chosen slag and for the crystallization of the metal in the case of esr. In an earlier work, an ultrahigh strength steel, designated as 03ccrmov esr 03c10mo03v, which is a modified version of afnor 15cdv6 steel, has been developed by increasing carbon content from 015 to 028% and by processing the steel through electroslag refining esr with inoculation by either niobium or zirconium during esr. As the developing droplets pass through the slag, the metal is cleaned of nonmetallic impurities which are removed by chemical reaction with the slag or by physical. Prasad department of metallurgy, indian institute of science, bangalore 560012, india abstracthe aisi 4340 steel has been.
Problems of special electrometallurgy, 3, 2002, 10. Coldstarting techniques for use with the experimental electroslag refining furnace at mrl have been examined. Based on more than forty years of experience with both processes, deutsche edelstahlwerke have excellent knowhow and process engineering in place, which is optimally adapted to meet their customers requirements. Consumable electrode furnace for electroslag refining download pdf info publication number us3389208a. Electroslag remelting esr, also known as electroflux remelting, is a process of remelting and refining steel and other alloys for missioncritical applications in aircraft, thermal power stations, nuclear power plants, military technology, etc the electroslag remelting esr process is used to remelt and refine steels and various superalloys, resulting in highquality ingots. Dec 12, 2014 single or multiple solid as well as fluxcored electrodes may be used.
The molten droplets formed at the tip of the electrode fall through the molten slag, and collect in a pool on the baseplate to solidify. Flux samples were prepared using a rapid sodium carbonateborate fusion with subsequent digestion in dilute nitric acid prior to chelant. The ingots are used for manufacturing heavy parts for electric power generating units turbine shafts, generator rotor shafts. A bottom pour electroslag refining system refines raw material into refined liquid metal. The steel dripping from the electrode is then freed from contamination.
Electroslag remelting esr, also known as electroflux remelting, is a process of remelting and refining steel and other alloys for missioncritical applications in aircraft, thermal power stations, nuclear power plants, military technology, etc. On melting of electrodes during electroslag remelting. Control of hydrogen during esr process sciencedirect. Electroslagwelding, cost effective vertical one pass process. In electroslag refining the slag normally provides a cover for the molten metal or alloy pool and eliminates the costly vacuum systems that are required for vacuumarc melting. Iron reduction in aluminum by electroslag refining. Electroslag welding was derived from a metal manufacturing process called electroslag remelting or refining esr. It principle is based on the electroslag welding process. Investigation on the effect of electrode tip on formation of metal. Two coldstarting devices based on exothermic reactions and resistanceheating, respectively, have both been developed to the stage where reliable starting can be achieved. The current work is devoted to the investigation of oxygen impact on the structure and properties of titanium. Strip cladding has been around for decades, and historically, submerged arc strip cladding sasc has been the most commonly used process, offering deposition rates of about 33 pounds per hour. Experimental results indicate that the iron content decreases with increasing na 2 b 4 o 7 addition and remelting time, and the iron content decreases from 0.
The current running through the slag via the electrode heats up the slag due to its high electric resistance to the point that the tip of the electrode, which is immersed in the slag, is liquefied. Jul 22, 1975 the present invention relates generally to an electroslag refining process for uranium and uranium alloys, and more particularly to such a process where scrap material is refined in such a manner that the oxygen content therein is reduced to less than about 100 parts per million ppm. Nov 26, 2019 titanium is widely used in specific applications due to its high strength, low density and good chemical stability. The electroslag refining experiments were carried out using kclnaclna 3 alf 6 slag. Flux for electroslag welding sandvik 37s se811 81 sandviken sweden march 2005 general description sandvik 37s is a highly basic, agglomerated flux for electroslag strip surfacing. Electroslag remelting article about electroslag remelting. Process for electroslag refining of uranium and uranium. Factors influencing power consumption and powersaving measures. Esw is similar to electrogas welding, but the main difference is the arc starts in a different location. In the first part the heat necessary to melt an electrode with a flat tip shape is calculated. Effect of electroslag refining on microstructure and. May 14, 2014 many factors influence the nonmetallic inclusions in electroslag steel including furnace atmosphere and inclusions content in the consumable electrode, slag amount and its composition, power input, melting rate, filling ratio, and so on.90 1518 426 38 1455 819 493 644 915 44 251 1002 1194 1528 825 96 1178 700 616 643 1394 451 379 1504 552 868 500 188 1049 483 636 1144 871 1531 1234 718 1442 1320 34 1360 522 78 1181